Shortly after the discovery of penicillin in 1929, Alexander Fleming already pointed out the possibility of resistance during an interview with the New York Times. The first case of penicillin resistance was reported only one year after clinical trials began; within 20 years, 80% of Staphylococcus aureus isolates were resistant to penicillin (Lobanovska and Pilla, 2017).

Over the years, clients and patients have gotten used to receiving a pill to quickly fix their ailments. Often, antibiotics have been prescribed for illnesses they were not effective against, including viral challenges. This has unnecessarily accelerated the rate of resistance development. To reverse this trend, education is key. At the same time, the judicious use of antibiotics, meaning the correct antibiotic for the challenge plus proper administration and duration of use, is paramount for all medical professionals to help preserve the efficacy of these critical substances.

Antibiotic use in animal production must be reduced

For many years, animal producers have used antibiotics as growth promoters. The E.U. banned this type of use in 2006, and the United States followed in 2017. Evaluations have shown a decrease in antibiotic use in the U.S.: In 2014, according to the FDA, 17,000 tons of antibiotics were sold in the United States for livestock, representing 80 percent of all U.S. antibiotics sales. In 2019, a total of about 11,000 tons of antibiotics were sold for use in food-producing animals (FDA, 2020).

As the number of isolated multi-drug resistant bacteria increases and the discovery and approval of new antibiotics slows, it is imperative that the use of antibiotics in animal production, especially those that are critically important for humans, is reduced to a minimum. Hence, antibiotics should only be used to treat, control, or prevent diseases in case of imminent risk, but not for growth-promoting purposes.

Scanning electron micrograph of methicillin-resistant Staphylococcus aureus bacteria (yellow) and a dead human white blood cell (red). Credit: National Institute of Allergy and Infectious Diseases/NIH

Customers’ requests for antibiotic-free chicken push antibiotic reduction

Many birds are already raised without antibiotics in the US and elsewhere because of the demands of the market. Since 2016, chicken antibiotic sales decreased by 62% (Dall, 2020). Frequently, the goal of these antibiotic-free (ABF) production programs is to differentiate products in a highly competitive commodity market. The reduction of antibiotic use has been a secondary, generally unintended consequence.

Nevertheless, to meet customer demands for ABF products, antibiotics that are not important to human health but for production (e.g., ionophores) have also been eliminated. In many cases, this has negatively affected growth performance and bird health. As the requirements for production efficiency and welfare standards increase, transitioning from “conventional” to ABF production poses a challenge for everyone involved.

Antibiotic reduction through improved management

One must never trade animal welfare for reduced antibiotics use, but the need for them can be decreased through improved management practices. Flock health starts with genetics companies selecting birds that are resilient to disease and management challenges and continues all the way to the processing plant. All of the inputs and practices must be optimized in modern poultry production to maintain a high level of performance and animal welfare while reducing reliance on antibiotics.

Antibiotic-free requires diligent management

When antibiotics are not available, attention to detail becomes more decisive. All aspects of production are important, but the most critical stages are those that affect the downstream process. The pullets, breeders, and hatchery require the most meticulous care. Additionally, all production factors must meet the highest quality standards: feed, light, air quality, water quality, litter quality, biosecurity, vaccination, sanitation, nutrition and feeding.

Antibiotic reduction requires meticulous attention to detail to safeguard animal welfare.

Non-antibiotic feed additives support ABF programs

ABF production is all about sustainability. For agricultural operations to survive and thrive in the future, one has to move away from the old paradigm of “saving the way to success”. This is not impossible in ABF production, but misses out on the larger picture of long-term profitability, investment in innovation, and system change.

Non-antibiotic feed and water additives are essential resources to support sustainable management. To mention a few, probiotics, prebiotics, toxin binders, organic acids, and phy­tomolecules are all options for reducing the need for antibiotics based on different modes of action. Phytomolecules, for example, often have antimicrobial properties, some toxin binders can bind bacterial toxins, and pre- and probiotics support the gut flora. There are many kinds of solutions on the market; the key is to find the right ones for your issues.

Antibiotic stewardship: together for a healthier future

There is already a large body of literature demonstrating the benefits of alternative or complementary solutions. More importantly, there are already many people that successfully raise birds and other animals without antibiotics. Whenever possible, leverage your professional network and talk to trusted people with unique experiences. Working together, we can build a healthier future for people and animals.

The Antibiotic Reduction series

The series that debuts here consists of a set of articles offering professionals a practical overview of poultry production with reduced antibiotic use. The independent expert in charge, starting with the next article in the series, is Dr. TJ Gaydos, who holds a Master’s degree in Avian Medicine and is a diplomate of the American College of Poultry Veterinarians.

Dr. Gaydos works with integrated poultry companies and allied industries, focusing on bird health and antibiotic-free production performance. He has spent his veterinary career working to improve intestinal health, animal welfare, production efficiency, and reduce zoonotic diseases. He works extensively with intestinal health, probiotics and prebiotics, and other non-antimicrobial feed additives.

Topics covered under Dr. Gaydos’s guidance include biosecurity, nutrition, pullet management, hatchery sanitation, gut health, and more. Together they provide an extensive look at the producers’ pain points and potential strategies to maintain bird health while mitigating the need for antibiotics.

References

AccessScience Editors, “U.S. Bans Antibiotics Use for Enhancing Growth in Livestock.” Access Science. McGraw-Hill Education, January 1, 1970. https://www.accessscience.com/content/u-s-bans-antibiotics-use-for-enhancing-growth-in-livestock/BR0125171.

Dall, Chris. “FDA Reports Another Rise in Antibiotic Sales for Livestock.” FDA Reports Another Rise in Antibiotic Sales for Livestock | International Biosecurity and Prevention Forum, December 16, 2020. https://www.ibpforum.org/news/fda-reports-another-rise-antibiotic-sales-livestock.

Lobanovska, Mariya, and Giulia Pilla . “Penicillin’s Discovery and Antibiotic Resistance: Lessons for the Future?” Yale Journal of Biology and Medicine. 90, no. 1 (March 29, 2017): 135–45.

U.S. Food and Drug Administration. “2020 Summary Report On Antimicrobials Sold or Distributed for Use in Food-Producing Animals” Food and Drug Administration, 2019. https://www.fda.gov/media/144427/download.

The threat of molds and yeasts in animal feed

Yeasts and molds can have both positive and negative effects on products consumed by animals and humans. On the one hand, yeasts are used to produce fermented products, such as bread, wine, and beer. On the other hand, yeasts and molds promote the spoilage of raw materials, food, and feeds (Lowes et al., 2000). Molds are among the most potent food and feed spoilers. They can be very resilient to environmental stress, which is a concern in climate change scenarios (Perrone et al., 2020) and enables them to withstand feed preservation measures (Punt et al., 2020).

Several hundred species of molds and yeasts can invade a large variety of raw materials and feeds. They show an easy adaptation to different environments; for instance, they can grow and reproduce in media with pH levels ranging from 2 to above 9 (Tournas et al., 2001). However, the majority of yeasts and molds require free oxygen to grow and thrive.

Excess moisture, high water activity, and high temperatures in feedstuffs are the main mold growth factors that concern the feed industry (Mohapatra et al., 2017).  At storage, grains’ moisture content should not exceed 13%, and the water activity of raw materials, feedstuffs, and finished feed should be maintained below 0.8 (Dijksterhuis et al., 2019).  Controlling these points contributes to preventing the growth of most pathogens and undesirable microorganisms.

Mold growth reduces the nutritional value of feed, which affects animal health and performance

The microbiology of molds and how they affect the feed

The microbial growth dynamic of grain storage depends on several factors, including the harvest season, grain temperature and moisture content, as well as the type of facility and its environment. For instance, in some areas, grains are harvested at the beginning of the cold season and stored through the following warm season. Storage molds constitute a significant threat to the quality of these raw materials, especially during the warm months, when the stored grains may become hotter than the surrounding environment. This leads to condensation, which increases moisture and water activity. Molds easily thrive in these conditions.

Storage molds reduce the nutritional and commercial value of grains and feeds. For grains, their commercial value decreases when the appearance of kernels changes in a manner recognized by the grain industry as kernel damage. The chemical composition of feeds may deteriorate due to enzymatic actions, resulting in a loss of nutrients (energy, vitamins) and the production of free fatty acids and other unwanted by-products (Reed et al., 2007).

Extensive research has established the factors that influence mold-induced deterioration during grain storage and which management strategies are required:

• Moisture content and water activity (a function of the temperature, moisture content, and substrate) – Microorganisms have a limiting water activity below which they cannot grow; therefore, drying the grains below that critical level is part of an effective mold control strategy (Mannaa & Kim, 2017).
• Temperature – Grain-contaminating molds thrive in tropical regions, where high temperature and humidity conditions predominate. In general, molds are inactive if the grains are stored below 20 °C (Mousa et al., 2013). However, the temperature of stored grains increases as molds begin to grow in the warmer and/or wetter parts of the grain/feed mass and feed, and heat is generated due to respiration, accelerating the deterioration rate. Moreover, the presence of a temperature gradient in the feedstuffs causes air to move, accelerating the transfer of moisture to cooler grain (Mannaa & Kim, 2017).
• Grain quality, including previous storage conditions, insect infestation, presence of broken kernels, and impurities – When grain is too warm, the rate of insects’ breeding is higher (they respond to higher temperatures), the grain contains more humidity and may carry fungal spores. Broken kernels are an easier target for mold and insect infestations than whole ones, increasing the possibility of spoilage (Marcos Valle et al., 2021).
• Duration of storage, management, and aeration influence the oxygen and carbon dioxide concentration in the grain mass, which plays a role in mold growth (Marcos Valle et al., 2021).

The consequences of storage deterioration include:

• worse organoleptic properties (aspect, texture, taste, and aroma) of grains and feeds
• more kernel damage,
• higher fat acidity,
• slight increase in protein content as non-protein constituents are consumed by mold respiration, causing
• lower energy value of the grain/feed (Reed et al., 2007), and
• lower content of vitamins A, B1, D3, E, and K.

Molds and mycotoxins: a toxic relationship for animal health

Beyond their negative impact on feed quality, some fungal genera such as Aspergillus, Penicillium, Alternaria, and Fusarium can produce mycotoxins, secondary metabolites that have toxic effects on humans and animals (Greco et al., 2015). Roughly 60% of raw materials produced for agriculture purposes worldwide are estimated to be contaminated by fungi and mycotoxins (Eskola et al., 2020). Mycotoxins can induce toxic, carcinogenic, and mutagenic reactions even at low concentrations. Their presence in the final feed is a sign of alert as, usually, these metabolites are resistant to technological treatments. Thus, it is important to stop them from entering the feed production chain (Leyva Salas et al., 2017).

Feed-contaminating Fusarium species produce mycotoxins such as trichothecenes, zearalenone, and Fumonisin.

Organic acids: Unrivaled in preventing feed spoilage

It is crucial to reduce the feed losses and improve animal health by controlling fungal contamination at all stages of the feed production chain: from pre-harvest strategies on the field to post-harvest management during storage and even at feed processing. Throughout these processes, producers can apply different management practices. For instance, in field crops, fungal growth can be prevented through crop rotation and tillage; the use of fungicides is a later measure when mold presence exceeds critical levels.

Post-harvest management of grains and their by-products includes drying and storage management through moisture and temperature monitoring and aeration programs. Other spoilage-prevention measures include good hygiene practices and thermal treatments in feed production. However, feed producers and farmers face limitations in applying and linking such measures to tackle the occurrence of these undesirable pathogens (Dijksterhuis et al., 2019).

Certain organic acids, such as propionic, sorbic, benzoic, and acetic acids, have proven effective in preventing mold growth and feed spoilage. These organic acids are used globally now, not only for improving animal nutrition but also for supporting animal health (Dijksterhuis et al., 2019).

Pro-Stabil BSL is a product that harnesses the feed preservation effects of organic acids and combines them with surfactants. This means that it can offer a strong yeast and mold inhibition while maintaining the moisture in feed, thus reducing the risk of microbial challenges while prolonging the shelf life of feedstuffs and compound feeds.

Trial results: Pro-Stabil BSL is a great tool to reduce mold growth and manage moisture

Pro-Stabil BSL contains a synergistic blend of organic acids and a surfactant that leads to

» Improved moisture dispersion in the feed

» Increased water retention (reduced water activity)

» Improved anti-mold agent dispersion in the feed and grain

Trial results show a significant decrease in mold growth when Prostabil BSL was added to compound feed. In addition, when moisture was added at 2%, moisture from the environment was also observed, but the mold counts still decreased (Figure 1).

Figure 1: Effects of Pro-Stabil BSL with addition of 2 % moisture on feed quality indicators

When adding Pro-Stabil BSL to animal feed, the following benefits can be expected:

• Reduction and prevention of mold growth and recontamination
• Improved moisture management
• Improved feed mill efficiency production
• Improved microbiological quality of grains and feed
• Shrinkage management by increasing moisture in feed with no risk of mold development
• Reduced water dissipation

Mold growth can lead to sensory defects in feed and reduce its nutritional value. It can also harm animals through the production of mycotoxins. Pro-Stabil BSL offers a safe solution that is also easy to handle. Using the preservative properties of organic acids, Pro-Stabil BSL helps to reduce feed spoilage and its associated effects on animal health and performance.

References

Dijksterhuis, Jan, Martin Meijer, Tineke van Doorn, Jos Houbraken, and Paul Bruinenberg. “The Preservative Propionic Acid Differentially Affects Survival of Conidia and Germ Tubes of Feed Spoilage Fungi.” International Journal of Food Microbiology 306 (2019): 108258. https://doi.org/10.1016/j.ijfoodmicro.2019.108258.

Eskola, Mari, Gregor Kos, Christopher T. Elliott, Jana Hajšlová, Sultan Mayar, and Rudolf Krska. “Worldwide contamination of food-crops with mycotoxins: Validity of the widely cited ‘FAO estimate’ of 25%.” Critical Reviews in Food Science and Nutrition 60, no. 16 (2020): 2773-2789. https://doi.org/10.1080/10408398.2019.1658570

Greco, Mariana, Minna Kemppainen, Graciela Pose, and Alejandro Pardo. “Taxonomic Characterization and Secondary Metabolite Profiling Of Aspergillus Section Aspergillus Contaminating Feeds And Feedstauffs.” Toxins 7, no. 9 (2015): 3512–37. https://doi.org/10.3390/toxins7093512.

Harein, P., & Meronuck, R. (1995). Stored grain losses due to insects and molds and the importance of proper grain management. In V. Krischik, G. W. Cuperus, & D. Galliart (Eds.), Stored product management (pp. 29e31). Oklahoma Cooperative Extension Service Publication. E-912.

Leyva Salas, Marcia, Jérôme Mounier, Florence Valence, Monika Coton, Anne Thierry, and Emmanuel Coton. “Antifungal Microbial Agents for Food Biopreservation—a Review.” Microorganisms 5, no. 3 (2017): 37. https://doi.org/10.3390/microorganisms5030037.

Lowes, K. F., C. A. Shearman, J. Payne, D. MacKenzie, D. B. Archer, R. J. Merry, and M. J. Gasson. “Prevention of Yeast Spoilage in Feed and Food by the Yeast Mycocin Hmk.” Applied and Environmental Microbiology 66, no. 3 (2000): 1066–76. https://doi.org/10.1128/aem.66.3.1066-1076.2000.

Mannaa, Mohammed, and Ki Deok Kim. “Influence of temperature and Water activity on Deleterious fungi AND Mycotoxin production during grain storage.” Mycobiology 45, no. 4 (2017): 240–254. https://doi.org/10.5941/myco.2017.45.4.240.

Marcos Valle, F. J., Castellari, C., Yommi, A., Pereyra, M. A., & R. Bartosik. “Evolution of grain microbiota during hermetic storage of corn (zea mays l.).” Journal of Stored Products Research 92 (2021): 101788. https://doi.org/10.1016/j.jspr.2021.101788.

Mohapatra, D., Kumar, S., Kotwaliwale, N., and K. K. Singh. “Critical factors responsible for fungi growth in stored food grains and non-Chemical approaches for their control.” Industrial Crops and Products 108 (2017): 162–182. https://doi.org/10.1016/j.indcrop.2017.06.039.

Mousa, W., Ghazali, F. M., Jinap, S., Ghazali, H. M., and S. Radu. “Modeling growth rate and assessing AFLATOXINS production by Aspergillus flavusas a function of Water activity and temperature on polished and brown rice.” Journal of Food Science 78, no. 1 (2013). https://doi.org/10.1111/j.1750-3841.2012.02986.x.

Perrone G, Ferrara M, Medina A, Pascale M, and N. Magan. “Toxigenic Fungi and Mycotoxins in a Climate Change Scenario: Ecology, Genomics, Distribution, Prediction and Prevention of the Risk.” Microorganisms 8, no. 10 (2020): 1496. https://doi.org/10.3390/microorganisms8101496.

Punt, Maarten, Tom van den Brule, Wieke R. Teertstra, Jan Dijksterhuis, Heidy M.W. den Besten, Robin A. Ohm, and Han A.B. Wösten. “Impact of Maturation and Growth Temperature on Cell-size Distribution, Heat-Resistance, Compatible Solute Composition and Transcription Profiles of Penicillium Roqueforti Conidia.” Food Research International 136 (2020): 109287. https://doi.org/10.1016/j.foodres.2020.109287.

Reed, Carl, Stella Doyungan, Brian Ioerger, and Anna Getchell. “Response of Storage Molds to Different Initial Moisture Contents of Maize (Corn) Stored AT 25°C, and Effect on Respiration Rate and Nutrient Composition.” Journal of Stored Products Research 43, no. 4 (2007): 443–58. https://doi.org/10.1016/j.jspr.2006.12.006.

Tournas, Valerie, Michael E. Stack, Phillip B. Mislivec, Herbert A. Koch, and Ruth Bandler. “Bacteriological Analytical Manual Chapter 18: Yeasts, Molds and Mycotoxins.” U.S. Food and Drug Administration. April 2001. https://www.fda.gov/food/laboratory-methods-food/bam-chapter-18-yeasts-molds-and-mycotoxins.

By Technical Team, EW Nutrition

In modern swine production, one of the key aspects for success is a balanced diet. This essentially means ensuring that the animal meets its daily nutritional requirements for maintenance, growth, and reproduction. In order to provide an appropriate diet and safe feed for the animals, the sensory and nutritional characteristics of the feed must be preserved and issues like the oxidation of the feed must be avoided.

This article aims to highlight why oxidation in  feed can become a big concern for swine producers, what the problems resulting from oxidation in pig feed are, and present practical solutions to improve feed quality and pig performance by controlling the oxidation.

Feed oxidation: What are the dangers?

In pig diets, various sources of lipids are added to increase caloric density, provide essential fatty acids, improve feed palatability, improve pellet quality, and reduce dust (Keer et al., 2015). Some of the feed ingredients are more susceptible to oxidation because of their physical and chemical characteristics, such as milled grains and ingredients of animal origin and vegetable oils with a high content of polyunsaturated fatty acids.

Oxidative rancidity is a type of lipid deterioration. In the oxidation process, the free radicals react with lipids and proteins and induce cellular and tissue damage.

Some consequences of oxidative deterioration are the destruction of fat-soluble vitamins, supplemental fats, and oils. Preserving these ingredients is crucial because fats and oils provide a high quantity of energy and essential fatty acids. At the same time, vitamins, such as those present in vitamin premixes, are indispensable for optimal animal growth and performance.

The oxidation process also results in by-products with strong unpleasant taste and odor, and even toxic metabolites. In addition, oxidized feed has less protein, amino acids, and energy content. All these factors are relevant when resources, in the current scenario of high prices of feed ingredients and inputs, might be wasted due to poor feed management.

Performance losses caused by oxidation

Lipid oxidation can incur several losses regarding the pigs’ performance. Feeding oxidized lipids significantly decreases growth rate, feed intake and efficiency, immune function, and weight gain efficiency in pigs, especially in breeding animals, since the exposure occurs over long periods.

The ingestion of products resulting from the oxidative deterioration of fatty acids leads to irritability of the intestinal mucosa, diarrhea, and, in extreme cases, can result in liver degeneration and cell death. DeRouchey et al. (2004) observed reduced growth rates in pigs that are fed rancid white grease. Ringseis et al. (2007) reported that feeding oxidized sunflower oil increased oxidative stress markers in the small intestine of pigs, while Boler et al. (2012) reported that feeding pigs oxidized corn oil reduced growth performance (Table 1). Lu et al. (2014a) reported signs of liver damage in pigs subjected to dietary oxidative stress, increasing plasma bilirubin content, and enlarged liver size.

Table 1. Effects of dietary corn oil quality and antioxidant inclusion on barrow performance (Source: Boler et al., 2012)

There are some theories as to why oxidized feed causes such effects. According to Dibner et al. (1996), vitamins and polyunsaturated fatty acids deteriorate in the absence of antioxidants, and oxidized fats and their byproducts can negatively affect cells, resulting in changes in membrane permeability, viscosity, secretory activity, and membrane-bound enzyme activity. These primary effects lead to observable systemic effects. In order to prevent these damaging consequences, antioxidants have become a widely used alternative.

The power of antioxidants

Chemical antioxidants (Table 2) are added to animal feeds to delay fat and vitamin oxidation, which keeps the diet palatable and helps prolong the feed’s shelf life, ultimately maintaining the quality of the ingredients (Jacela et al., 2010). They prevent the binding of oxygen to free radicals. Dietary antioxidants have also been used in several species of animals to replace vitamin E, which is known for its antioxidant powers. Antioxidants are highly applicable in warm climates, when high levels of fat are added to the diet, and in areas where byproducts high in unsaturated fats are commonly used.

Table 2. Commonly used chemical antioxidants

Lu et al. (2014b) studied the effects of dietary supplementation with a blend of antioxidants (ethoxyquin and propyl gallate) on carcass characteristics, meat quality, and fatty acid profile in finishing pigs fed a diet high in oxidants. They reported that the inclusion of antioxidants minimized the effects of the high oxidant diet. The treatments including antioxidants, whether combined with vitamin E or not, had positive results in carcass weight, back fat, loin characteristics, and extractable lipid percentage.

Fernandez-Duenas (2009) studied the use of antioxidants in feed containing fresh or oxidized corn oil and its effects on animal performance, the oxidative status of tissues, meat quality, shelf life, and the antioxidant activity of skeletal muscle of finishing pigs. They reported that barrows fed with diets with the antioxidant blend showed increased feed efficiency. Orengo et al. (2021) showed that feeds protected with antioxidants could compensate for low vitamin E supply with regard to growth performance in the starter phase. Hung et al., 2017 theorized that the impacts on growth performance are likely related to the lack of adequate antioxidant capacity of the diet and oxidative stress status.

As literature and application results show, the use of antioxidants in pig feed is crucial to minimize adverse effects from oxidized feed and allow the animals to express their full performance potential.

SANTOQUIN: preserving feed quality

From a practical standpoint, swine producers must consider some criteria for selecting a good antioxidant, which must preserve feed components, be nontoxic for humans and pigs, show effectiveness at very low concentrations, and be economically sustainable.

Considering those major characteristics, EW Nutrition offers a range of antioxidant solutions for the preservation of feed ingredients and feeds for poultry and swine through their SANTOQUIN product line. Santoquin is a feed preservative that protects supplemental fats, oils, meals, and vitamin premixes and protect feed from oxidation. Santoquin provides unsurpassed protection from oxidative rancidity, and it has proven effects against oxidation in feeds (Figure 1) ensuring the prolonged shelf life of feeds, especially during suboptimal storage conditions, such as those with high environmental temperature and elevated levels of moisture.

Figure 1. Antioxidant efficacy and competitiveness. SANTOQUIN MAX feed preservative is a proprietary antioxidant blend that effectively prolongs the shelf life of feed and feed ingredients by reducing oxidation rate.

Studies have been conducted to show the beneficial effects of Santoquin. Ethoxyquin, contained in Santoquin, has been used in the swine industry for over five decades and has been shown to improve growth performance and markers of oxidative status in pigs (Dibner et al., 1996). Ethoxyquin is also known for being the most efficacious and cost-effective antioxidant. Lu et al. (2014b) showed that the addition of an antioxidant blend (ethoxyquin and propyl gallate) protected pigs fed with a high-oxidant diet from oxidative stress more efficiently than vitamin E supplementation (Figure 2).

Figure 2. Concentrations of vitamins A and E across treatments in the plasma (A) and muscle (B). HO: high oxidant diet containing 5% oxidized soybean oil (peroxide value at approximately 180 mEq/kg of oil, 9 mEq/kg in the diet) and 10% of a PUFA source (providing approximately 55.57% of crude fat that contains docosahexaenoic acid [ DHA] at 36.75%, and 2.05% DHA in the diet); VE: the HO diet with 11 IU/kg of added vitamin E; AOX: the HO diet with an antioxidant blend (ethoxyquin and propyl gallate, 135 mg/kg); VE+AOX: the HO diet with both vitamin E and antioxidant blend; SC: a standard corn–soy control diet with nonoxidized oil and no PUFA source. The HO pigs were switched to the SC diet after day 82 as an intervention for poor health and performance. The samples came from two pigs from each pen. The VE treatment lost 1 replicate during the feeding phase and transportation period (n = 4), while in other treatments, n =5. (Source: Lu et al., 2014b)

Conclusion

The negative effects of oxidation in pig feed can result in diets with lower biological energy value. To avoid that, antioxidants help maintain intestinal health, ensure a safe food intake, preserve the ingredients and resources used in pig production. Overall, antioxidants help swine producers improve feed conversion and achieve more productive animals and lower mortality caused by toxicity. At the end of the day, the use of antioxidants is associated with better profitability.

References

Boler, D. D., Fernández-Dueñas, D. M., Kutzler, L. W., Zhao, J., Harrell, R. J., Campion, D. R., Mckeith, F. K., Killefer, J., & Dilger, A. C. (2012). Effects of oxidized corn oil and a synthetic antioxidant blend on performance, oxidative status of tissues, and fresh meat quality in finishing barrows. Journal of Animal Science, 90(13), 5159–5169. https://doi.org/10.2527/jas.2012-5266

DeRouchey, J. M., Hancock, J. D., Hines, R. H., Maloney, C. A., Lee, D. J., Cao, H., Dean, D. W., & Park, J. S. (2004). Effects of rancidity and free fatty acids in choice white grease on growth performance and nutrient digestibility in weanling pigs. Journal of Animal Science, 82(10), 2937–2944. https://doi.org/10.2527/2004.82102937x

Dibner, J. J., Atwell, C. A., Kitchell, M. L., Shermer, W. D., & Ivey, F. J. (1996). Feeding of oxidized fats to broilers and swine: Effects on enterocyte turnover, hepatocyte proliferation and the gut associated lymphoid tissue. Animal Feed Science and Technology, 62(1 SPEC. ISS.), 1–13. https://doi.org/10.1016/S0377-8401(96)01000-0

Fernández-dueñas, D. M. (2009). Impact of oxidized corn oil and synthetic antioxidant on swine performance, antioxidant status of tissues, pork quality, and shelf life evaluation.

Hung, Y. T., Hanson, A. R., Shurson, G. C., & Urriola, P. E. (2017). Peroxidized lipids reduce growth performance of poultry and swine: A meta-analysis. Animal Feed Science and Technology, 231, 47–58. https://doi.org/10.1016/j.anifeedsci.2017.06.013

Jacela, J. Y., DeRouchey, J. M., Tokach, M. D., Goodband, R. D., Nelssen, J. L., Renter, D. G., & Dritz, S. S. (2010). Feed additives for swine: Fact sheets–flavors and mold inhibitors, mycotoxin binders, and antioxidants. Journal of Swine Health and Production, 18(1), 27-32.

Kerr, B. J., Kellner, T. A., & Shurson, G. C. (2015). Characteristics of lipids and their feeding value in swine diets. Journal of Animal Science and Biotechnology, 6(1), 1-23. https://doi.org/10.1186/s40104-015-0028-x

Lu, T., Harper, A. F., Zhao, J., Estienne, M. J., & Dalloul, R. A. (2014). Supplementing antioxidants to pigs fed diets high in oxidants: I. Effects on growth performance, liver function, and oxidative status. Journal of animal science, 92(12), 5455-5463. https://doi.org/10.2527/jas.2013-7109

Lu, T., Harper, A. F., Dibner, J. J., Scheffler, J. M., Corl, B. A., Estienne, M. J., Zhao, J., & Dalloul, R. A. (2014b). Supplementing antioxidants to pigs fed diets high in oxidants: II. Effects on carcass characteristics, meat quality, and fatty acid profile. Journal of Animal Science, 92(12), 5464–5475. https://doi.org/10.2527/jas.2013-7112

Orengo, J., Hernández, F., Martínez-Miró, S., Sánchez, C. J., Peres Rubio, C., & Madrid, J. (2021). Effects of commercial antioxidants in feed on growth performance and oxidative stress status of weaned piglets. Animals, 11(2), 1–13. https://doi.org/10.3390/ani11020266

Ringseis, R., Piwek, N., & Eder, K. (2007). Oxidized fat induces oxidative stress but has no effect on NF-κB-mediated proinflammatory gene transcription in porcine intestinal epithelial cells. Inflammation Research, 56(3), 118–125. https://doi.org/10.1007/s00011-006-6122-y

VISBEK, GERMANY, 23 August – Bad news for feed producers: after supply chain disruptions and raw material unavailability, now weather-related challenges in Europe will most likely affect this year’s crop quantity and quality. Cold temperatures, heatwaves, tornados, and hailstorms are expected to adversely affect the quality and quantity of the harvest.

The moisture brought by the rainfalls is generally expected to affect the quality of the crops. The torrential rains in France, Germany, etc. have darkened Central and Western farmers’ prospects: while the quantity may be there, the quality of wheat and corn is under question. Sprouting grains, diseased crops, and fungi may dampen the optimism brought by numbers alone.

Further east, droughts have posed different issues. Still, countries such as Romania and Bulgaria seem to have weathered the challenges somewhat better and are seeing YoY increases in their wheat and corn crop output.

In Great Britain, rainfall has not caused dramatic drops in crop output but has nevertheless greatly increased mycotoxin risk up to a “moderate to high” level.

Depending on the type of mycotoxin, weather challenges and storage conditions are the most common contributors to severe infestation. This year’s intemperate weather has, in fact, been ideal for a large spectrum of fungi. Fungal risks can be calculated at the two critical times: at flowering and at harvest and baling, when there is an increased risk of storage molds and mycotoxin production.

Preliminary analysis shows Europe’s wheat crops at potential risk of DON, as well as potentially Aflatoxin and Fumonisin infestation and more. Specialists continue to collect and monitor harvest results and adjust recommendations; however, we can definitely expect the presence of moderate, if not quite high levels of mycotoxin risk this year.

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By Technical Team, EW Nutrition

In July, Public Health England (PHE), an executive agency of the Department of Health and Social Care in the United Kingdom, reported a rise of norovirus outbreaks in the country. Norovirus, a highly contagious virus similar to the coronavirus, is the main cause of viral food poisoning from shellfish. Symptoms include vomiting, diarrhea, cramps, as well as muscle aches and headaches.

The PHE press release shows an increase in outbreaks during the last two months, returning to pre-pandemic levels. According to the organization, the number of outbreaks has nearly tripled when compared to the same time period in the last 5 years, affecting people of all age groups and settings in England. Closed places where the virus can spread quickly, especially childcare facilities and nursing homes, are the most affected, as shown below.

Enteric virus outbreaks reported in England during the 2020/2021 season. Source:  National Norovirus and Rotavirus Bulletin, Public Health England, 2021 National Norovirus and Rotavirus Bulletin (publishing.service.gov.uk)

Norovirus: A global problem

The issue is not restricted to England. According to the CDC (Centers for Disease Control and Prevention), about one out of every five cases of acute gastroenteritis that leads to diarrhea and vomiting is caused by norovirus, responsible for over 200,000 deaths and a global economic burden of more than $60 billion. The large costs come from healthcare costs and productivity losses and can be seen in low, middle, and high-income countries as shown below.

Global economic burden of norovirus gastroenteritis. Source: https://doi.org/10.1371/journal.pone.0151219.t003

Prevention is key

Noroviruses is easily transmitted through contact with infected individuals or contaminated surfaces. There are many ways to reduce the spread of the virus (e.g., washing the hand thoroughly with soap and water) but prevention is key.

The outbreaks often occur from contaminated oysters or other shellfish which are consumed raw, making foodborne transmission accountable for a considerable number of cases. The conventional cleaning and purifying methods currently used in the industry cannot reliably reduce the number of norovirus contained in its digestive organ, therefore it is of extreme necessity to look new solutions to improve safety in shellfish production. And this is exactly what EW Nutrition does.

Combatting the norovirus: the IgY solution

With our mission to mitigate the impact of antimicrobial resistance in mind, we developed a new technology to improve food safety in shellfish production. Our solution is based on a high value source of natural egg immunoglobulins (IgY), which will prevent the virus from infecting the oyster’s digestive organ.

This method consists in adding anti-norovirus IgY to the seawater during the depuration process, which is a postharvest treatment where the shellfish are placed in tanks of clean seawater to reduce contaminant levels and allow shellfish to cleanse or purge themselves by continuation of their normal filter-feeding and digestive processes.

Natural, effective, and safe

While depuration is a highly effective and very common commercial practice for removing different pathogens, several studies show that the depuration process alone is not enough to remove completely or lower the norovirus to a safe level. On the other hand, various trial results show that shellfish treated with EW Nutrition technology is completely free from or has very low amount of live norovirus, allowing a safe consumption of raw oysters and minimizing the risk of any other outbreaks.

For more information about our solution, you can reach out to Lucas Queiroz or to your local EW Nutrition contact.

References

Bartsch et al. 2016. Global Economic Burden of Norovirus Gastroenteritis. https://doi.org/10.1371/journal.pone.0151219

 Lee, R.; Lovatelli, A.; Ababouch, L. Bivalve depuration: fundamental and practical aspects. FAO Fisheries Technical Paper. No. 511. Rome, FAO. 2008. 139p.

National Norovirus and Rotavirus Bulletin, Public Health England, 2021 National Norovirus and Rotavirus Bulletin (publishing.service.gov.uk)

Norovirus outbreaks increasing in England – GOV.UK (www.gov.uk)

Norovirus Worldwide | CDC

by Predrag Persak, Regional Technical Manager North Europe, EW Nutrition

The main sustainability challenge for broiler production lies in securing enough high-quality, nutritious, safe, and readily available food at a reasonable cost. At times, feed ingredients have to be included that are not nutritionally ideal and might compromise one’s broilers’ health and wellbeing. However, counteracting this threat with prophylactic antibiotics is not acceptable: We must minimize the use of antibiotics to mitigate antimicrobial resistance. The way forward is to go beyond static and linear nutritional value-to-price thinking. A dynamic nutritional strategy focusing on the interdependencies between ingredients, gut, microbiome, and digestion, enables sustainable ABF broiler production.

Sustainable ABF broiler production requires a dynamic, gut health-oriented nutritional strategy

Sustainability vs. ABF production – is there a trade-off?

The United Nations’ 1987 Brundtland report offers a clear definition of sustainability as “development that meets the needs of the present without compromising the ability of future generations to meet their own needs.” “Ability” includes the availability of resources – and in broiler production, which is one of the most efficient livestock productions, resources have always been a top priority. As a constantly evolving industry, broiler production has been quick to adopt sustainability into its management strategies. The use of the resource that is antibiotics, however, poses particular challenges.

Humans and animals depend on antibiotics to fight microbial infections. It is essential to maintain their efficacy so that future generations can lead healthy lives. Antibiotic efficacy is under threat from the development of antimicrobial resistance, which emerges from overuse and misuse in both human and veterinary medicine. Across the globe, broilers are still raised with the assistance of antibiotics. Either for disease therapy, to prevent disease occurrence, and still, in some parts of the world, to enhance performance. Driven by regulatory and consumer demands, broiler production with minimal or no use of antibiotics is rapidly gaining importance.

The challenges of antibiotic-free broiler production

ABF systems encounter numerous challenges since production requirements change drastically. Stock density must be lower; it takes longer to reach the desired weight; and more feed is needed to produce the same amount, with a higher risk of morbidity and mortality (Cervantes, 2015). The latter can result in more birds needing treatment with medically important antimicrobial drugs. All those challenges need to be overcome by adopting suitable strategies related to nutrition, genetics, management, biosecurity, welfare, and food safety.

As animal nutritionists, our focus lies on nutrition, feed, feed materials, additives, feed processing, feeding, and their (positive or negative) influence on the sustainability of ABF broiler production. However, we cannot look at these dimensions of production as a separate process. They are linked in the whole food chain and are affected by changes that happen in other related parts. An obvious example is feed production, which has an enormous impact on the overall sustainability of ABF broiler production:

• Due to raw material shortages, diets are becoming ever more complex, containing more single feed ingredients. For some of them, we need a better understanding of their impact on ABF broiler production (e.g., sunflower, rapeseed, beans, lupins).
• The nutritional composition of raw materials changes due to limitations in fertilizer use, and variability within the same raw material group is expected to increase.
• New food waste-reducing feed materials can enhance feed security but also require nutritional profiling to integrate them into diets.
• Local feed material production in humid and warm environments can introduce various pathogens into the feed/food chain.
• Increases in known and the emergence of new antinutrients and feed components that impair animal health, performance, and feed efficiency.
• Sustainability-driven pesticide reduction raises concerns about mycotoxins contaminating feed ingredients.
• Nutrient reduction to support gut health and, primarily, lower the excretion of nitrogen and phosphorous, negatively affects growth, nutritional standards, and the ability to freely select feed materials to include in broiler diets.
• The value (of which price is also part) of raw materials will be compromised, due to availability and nutritional variability.

Mycotoxin contaminated-feed can damage production animals’ performance, health, and welfare

When striving for a sustainable ABF broiler production approach, the possibility for errors becomes higher, while the error margin becomes smaller. The solution lies in helping the animals to mitigate the impact of stressors by focusing on the interaction of ingredients, gut, microbiome, and digestion. It is a holistic approach centered on gut health. Keeping the intestines BEAUTIful will help you produce in challenging conditions without the use of antimicrobials.

Keep the broiler gut BEAUTIful and resilient to stress

The BEAUTIful formula captures the six areas producers need to target for supporting broiler gut health:

Barrier

If it’s working correctly, the effective gatekeeper knows what gets in and what stays out. When the barrier function is compromised due to stress, pathogens can cause infections, disrupt health, and negatively impact broiler immunity. Necrotic enteritis, femoral head necrosis, and bacterial chondronecrosis with osteomyelitis (BCO) are common diseases that affect today’s broiler production (Wideman, 2015). As the source of nutrients, feed serves as a modulator of various physiological functions in the intestinal tract, including intestinal barrier function.

Enzymatic digestion

The gut is where endogenous and exogenous enzymes perform their hydrolysis functions to break down complex nutrients into the parts that can be used either by the intestinal tissue itself or for the whole animal. One part of hybrid enzymatic digestion is the fermentation by commensal microbes, in which complex materials form end-products of high biological values (such as short-chain fatty acids, SCFA).

Absorption

Maintaining the gut’s resorptive capacity is essential to secure the total intake of digested nutrients. Otherwise, pathogenic bacteria might use the excess nutrients to grow, form toxins, and affect the birds’ health and productivity.

United microbiome

The intestine of a broiler chicken is colonized by more than 800 species of bacteria and other inhabitants, such as viruses and simple organisms that are still unknown. By competitive exclusion and secretion of bacteriocins (volatile fatty acids, organic acids, and natural antimicrobial compounds), commensal bacteria keep the host safe from an overgrowth of dangerous bacteria (e.g., Salmonella, Campylobacter, and Clostridium perfringens). The fine-tuned diversity in the intestinal flora and balance in all interactions between it, the host, and the ingesta are needed for birds to stay healthy and perform well.

Transport

Birds’ digestive tract volumes are smaller than those of mammals with similar body weight. This means that they achieve more efficient nutrient digestion in a shorter retention time, averaging between 5 and 6 hours. Passing the small intestine usually takes around 3 hours, of which 1 hour is spent in the duodenum and jejunum. Transport times are affected by the feeding system and the extent to which material enters the caeca. Reflux of material from the distal to the proximal small intestine is an important feature that helps digestion and maintenance of a healthy gut.

Immunity

The intestinal microbiota is critically important for the development and stimulation of the immune system. The intestine is the key immunological organ, comprised of myeloid and lymphoid cells, and a site for producing many immune cell types needed to initiate and mediate immunity. Together with the microbiome, dendritic cells induce antigen-specific responses and form immunoglobulin A, which works in the intestinal lumen.

Natural gut health solution for sustainable ABF broiler production

In practice, supporting broiler gut health requires a holistic approach that includes natural feed additive solutions. Phytomolecules are compounds that certain plants develop as defenses mechanisms. Phytomolecules-based solutions should feature prominently in sustainable ABF broiler production approaches due to their advantageous properties:

Enhance digestion, manage variability

Sustainability necessitates efficient resource utilization. Digestion support needs to be a priority to use the available feed in its entirety. This is particularly important if antibiotics use needs to be minimized: a maximum of nutrients should be utilized by the animal; otherwise, they feed potentially harmful bacteria, necessitating antibiotic treatments. Enhancing digestibility is the focus when we are dealing with variable feed materials or feed changes that represent stress to the animal. Selected phytomolecules have proven efficient at improving performance due to enhanced digestion (Zhai et al. 2018).

Work on microbiome and pathogens

The antimicrobial activity of certain phytomolecules can prevent the overgrowth of pathogens in the gastrointestinal tract, thereby reducing dysbacteriosis (Liu et al., 2018) and specific diseases such as necrotic enteritis. Studies on broilers show that they also reduce the adhesion of pathogens to the wall of the intestine. Certain phytomolecules even possess antimicrobial characteristics against antibiotic-resistant pathogens.

Keep gut integrity

Phytomolecules help maintain tight junction integrity, thus preventing leaky gut (Li et al., 2009). As a result, the potential flow of bacteria and their toxins from the gut lumen into the bloodstream is mitigated. Their properties thus make phytomolecules a promising alternative to the non-therapeutic use of antibiotics. 

Trial results: Phytomolecules enhance broiler gut health

To test the efficacy of phytomolecules, we conducted a large-scale field study in Brazil, under practical conditions. The focus was on growth performance, and no growth-promoting antibiotics were used. Lasting 5 months, the trial involved more than 2 million broilers. The birds were divided into a control and a trial group, with two repetitions per group. Both groups were fed the standard feed of the farm. The trial group additionally received 100g of Activo per MT in its finisher feed for 3 weeks. The study clearly shows that Activo supplementation improves performance parameters (daily weight gain, average total gain, and improved feed efficiency), which resulted in a higher production efficiency factor (PEF):

• Activo groups had a 3 % higher average daily weight gain and reached their slaughtering age earlier
• The final weight of Activo groups was about 2.5 % higher than in the control group
• With a 2 points better feed conversion, the animals of the Activo group achieved a 13.67 points higher PEF

Figure 1: Broiler performance results, Activo vs. non-supplemented control group 

Conclusion

Antibiotic-free broiler production is a challenging endeavor: producers need to maintain animal welfare and keep up efficiency while making farming profitable. Over time, these challenges will affect producers even more as sustainability requirements increase across all parts of the broiler production chain. On top of that, coccidiostats, which are essential for efficient broiler production, are increasingly being questioned, which will require concerted research into feed additive solutions.

To make sustainable ABF broiler production the norm, it is unavoidable to adopt suitable strategies related to nutrition, genetics, management, biosecurity, welfare, and food safety. Effective, scientifically and practically proven tools already exist: Thanks to their positive impact on intestinal health, phytomolecules reliably support sustainable broiler production without antibiotics.

References

Cervantes, Hector M. “Antibiotic-Free Poultry Production: Is It Sustainable?” Journal of Applied Poultry Research 24, no. 1 (2015): 91–97. https://doi.org/10.3382/japr/pfv006.

Li, Y., H.Y. Cai, G.H. Liu, X.L. Dong, W.H. Chang, S. Zhang, A.J. Zheng, and G.L. Chen. “Effects of Stress Simulated by Dexamethasone on Jejunal Glucose Transport in Broilers.” Poultry Science 88, no. 2 (2009): 330–37. https://doi.org/10.3382/ps.2008-00257.

Liu, ShuDong, MinHo Song, Won Yun, JiHwan Lee, ChangHee Lee, WooGi Kwak, NamSoo Han, HyeunBum Kim, and JinHo Cho. “Effects of Oral Administration of Different Dosages of Carvacrol Essential Oils on Intestinal Barrier Function in Broilers.” Journal of Animal Physiology and Animal Nutrition 102, no. 5 (2018): 1257–65. https://doi.org/10.1111/jpn.12944.

Wideman, Robert F. “Bacterial Chondronecrosis with Osteomyelitis and Lameness in Broilers: a Review.” Poultry Science 95, no. 2 (2016): 325–44. https://doi.org/10.3382/ps/pev320.

Zhai, Hengxiao, Hong Liu, Shikui Wang, Jinlong Wu, and Anna-Maria Kluenter. “Potential of Essential Oils for Poultry and Pigs.” Animal Nutrition 4, no. 2 (2018): 179–86. https://doi.org/10.1016/j.aninu.2018.01.005.

Over the past 60 years, antibiotics have played an essential role in the swine industry as a tool that swine producers rely on to control diseases and to reduce mortality. Besides, antibiotics are also known to improve performance, even when used in subtherapeutic doses. The perceived overuse of antibiotics in pig production, especially as growth promoters (AGP), have raised concerns from governments and public opinion, regarding the emergence of multidrug-resistant bacteria, adding a threat not only to animal but also human health. The challenges raised regarding AGPs and the need for their reduction in livestock led to the development of combined strategies such as the “One Health Approach”, where animal health, human health, and the environment are interlaced and must be considered in any animal production system.

In this scenario of intense changes, swine producers must evaluate strategies to adapt their production systems to accomplish the global pressure to reduce antibiotics and still have a profitable operation.

Many of these concerns focus on piglet nutrition, since the use of sub-therapeutic levels of antimicrobials as growth promotors is still a regular practice for preventing post-weaning diarrhea in many countries (Heo et al., 2013; Waititu et al., 2015). Taking that into consideration, this article serves as a practical guide to swine producers through AGP removal and its impacts on piglet performance and nutrition Three crucial points will be addressed:

1. Why is AGP removal a global trend?
2. What are the major consequences for piglet nutrition and performance?
3. What alternatives do we have to guarantee optimum piglet performance in this scenario?

AGP removal: a global issue

Discussions on the future of the swine industry include understanding how and why AGP removal became such important topic worldwide. Historically, European countries have led discussions on eliminating AGP from livestock production. In Sweden, AGPs were banned from their farms as early as 1986. This move culminated into a total ban of AGPs in the European Union in 2006. Other countries followed same steps. In Korea, AGPs were removed from livestock operations in 2011. The USA is also putting efforts into limiting AGPs and the use of antibiotics in pig farms, as published in guidance revised by the Food and Drug Administration (FDA, 2019). In 2016, Brazil and China banned Colistin, and the Brazilian government also announced the removal of Tylosin, Tiamulin, and Lincomycin in 2020. Moreover, countries like India, Vietnam, Bangladesh, Buthan, and Indonesia have announced strategies for AGP restrictions (Cardinal et al., 2019; Davies and Walsh, 2018).

The major argument against AGPs and antibiotics in general is the already mentioned risk of the development of antimicrobial resistance, limiting the available tools to control and prevent diseases in human health. This point is substantiated by the fact that resistant pathogens are not static and exclusive to livestock, but can also spread to human beings (Barbosa and Bünzen, 2021). Moreover, concerns have been raised in regard to the fact that antibiotics in pig production are also used by humans – mainly third-generation antibiotics. The pressure on pig producers increased and it is today multifactorial: from official regulatory departments and stakeholders at different levels, who need to consider public concerns about antimicrobial resistance and its impact on livestock, human health, and the sustainability of farm operations (Stein, 2002).

It is evident that the process of reducing or banning antibiotics and AGPs in pig production is already a global issue and increasing as it takes on new dimensions. As Cardinal et al. (2019) suggest, that process is irreversible. Companies that want to access the global pork market and comply with increasingly stricter regulations on AGPs must re-invent their practices. This, however, is nothing new for the pig industry. For example, pig producers from the US and Brazil have adapted their operations in order to not use ractopamine to meet the requirements from the European and Asian markets. We can be sure, therefore, that the global pig industry will find a way to replace antibiotics.

With that in mind, the next step is to evaluate the consequences of AGP withdrawal from pig diets and how that affects the animals’ overall performance.

Consequences in piglet health and performance

Swine producers know very well that weaning pigs is challenging. Piglets are exposed to many biological stressors during that transitioning period, including introducing the piglets to new feed composition (going from milk to plant-based diets), abrupt separation from the sow, transportation and handling, exposure to new social interactions, and environmental adaptations, to name a few. Such stressors and physiological challenges can negatively impact health, growth performance, and feed intake due to immune systems dysfunctions (Campbell et al. 2013). Antibiotics have been a very powerful tool to mitigate this performance drop. The question then is, how difficult can this process become when AGPs are removed entirely?

Many farmers around the world still depend on AGPs to make the weaning period less stressful for piglets. One main benefit is that antibiotics will reduce the incidence of PWD, with subsequent improved growth performance (Long et al., 2018). The weaning process can create ideal conditions for the overgrowth of pathogens, as the piglets’ immune system is not completely developed and therefore not able to fight back. Those pathogens present in the gastrointestinal tract can lead to post-weaning diarrhea (PWD), among many other clinical diseases (Han et al., 2021). PWD is caused by Escherichia coli and is a global issue in the swine industry, as it compromises feed intake and growth performance throughout the pig’s life, also being a common cause for losses due to young pig death (Zimmerman, 2019).

Cardinal et al. (2021) also highlight that the hypothesis of a reduced intestinal inflammatory response is one explanation for the positive relationship between the use of AGPs and piglet weight gain.  Pluske et al. (2018) point out that overstimulation of the immune system can negatively affect pig growth rate and feed use efficiency. The process is physiologically expensive in terms of energy and also can cause excessive prostaglandin E2 (PGE2) production, leading to fever, anorexia, and reduction in pig performance. For instance, Mazutti et al. (2016) showed an increased weight gain of up to 1.74 kg per pig in animals that received colistin or tylosin in sub-therapeutic levels throughout the nursery. Helm et al. (2019) found that pigs medicated with chlortetracycline in sub-therapeutic levels increased average daily gain in 0.110 kg/day. Both attribute the higher weight to the decreased costs of immune activation determined by the action of AGPs on intestinal microflora.

On the other hand, although AGPs are an alternative for controlling bacterial diseases, they have also proved to be potentially deleterious to the beneficial microbiota and have long-lasting effects caused by microbial dysbiosis – abundance of potential pathogens, such as Escherichia and Clostridium; and a reduction of beneficial bacteria, such as Bacteroides, Bifidobacterium, and Lactobacillus (Guevarra et al., 2019; Correa-Fiz, 2019). Furthermore, AGPs reduced microbiota diversity, which was accompanied by general health worsening in the piglets (Correa-Fiz, 2019).

It is also important to highlight that the abrupt stress caused by suckling to weaning transition has consequences in diverse aspects of the function and structure of the intestine, which includes crypt hyperplasia, villous atrophy, intestinal inflammation, and lower activities of epithelial brush border enzyme (Jiang et al., 2019). Also, the movement of bacteria from the gut to the body can occur when the intestinal barrier function is deteriorated, which results in severe diarrhea and growth retardation. Therefore, nutrition and management strategies during that period are critical, and key gut nutrients must be used to support gut function and growth performance.

With all of that, it is more than never necessary to better understand the intestinal composition of young pigs and finding strategies to promote gut health are critical measures for preventing the overgrowth and colonization of opportunistic pathogens, and therefore being able to replace AGPs (Castillo et al., 2007).

Viable alternatives for protecting the piglets

The good news is that the swine industry already has effective alternatives that can replace AGP products and guarantee good animal performance.

Immunoglobulins from egg yolk (IgY) have proven to be a successful alternative to weaned piglet nutrition. Investigations have shown that egg antibodies improve the piglets’ gut microbiota, making it more stable (Han et al., 2021). Moreover, IgY optimizes piglet immunity and performance while reducing occurrences of diarrhea caused by E. coli, rotavirus, and Salmonella sp. (Li et al., 2016).

Phytomolecules (PM) are also potential alternatives for AGP removal, as they are bioactive compounds with antibacterial, antioxidant, and anti-inflammatory characteristics (Damjanović-Vratnica et al., 2011; Lee and Shibamoto, 2001). When used for piglet diet supplementation, phytomolecules optimize intestinal health and improve growth performance (Zhai et al., 2018).

Han et al. (2021) evaluated a combination of IgY (Globigen^® Jump Start, EW Nutrition) and phytomolecules (Activo^®, EW Nutrition) supplementation in weaned piglets’ diets. Results from that study (Table 1 and 2) showed that this strategy decreases the incidence of PWD and coliforms, increases feed intake, and improves the intestinal morphology of weaned pigs, making that combination a viable AGP replacement.

Table 1. Effect of dietary treatments on the growth performance of weaned pigs challenged with E. coli K88 (SOURCE: Han et al., 2021).

Table 2. Effect of dietary treatments on the post-weaning diarrhea incidence of weaned pigs challenged with E. coli K88 (%) (SOURCE: Han et al., 2021).

A trial conducted at the Institute of Animal Sciences of the Chinese Academy of Agricultural Sciences, China, supplemented weaning pigs challenged by E. coli K88 with a combination of PM (Activo^®, EW Nutrition) and IgY (Globigen^® Jump Start). The trial reported that this combination (AC/GJS) showed fewer diarrhea occurrences than in animals from the positive group (PC) during the first week after the challenge and similar diarrhea incidence to the AGP group during the 7th and 17th days after challenge (Figure 1).

Figure 1 – Incidence of diarrhea (%). NC: negative group, PC: positive group, AGP: supplementation with AGP, AC/GJS: combination of PM (Activo, EW Nutrition) and IgY (Globigen Jump Start).

The same trial also showed that the combination of these non-antibiotic additives was as efficient as the AGPs in improving pig performance under bacterial enteric challenges, showing positive effects on body weight, average daily gain (Figure 2), and feed conversion rate (Figure 3).

Figure 2 – Body weight (kg) and average daily gain (g). NC: negative group, PC: positive group, AGP: supplementation with AGP, AC/GJS: combination of PM (Activo, EW Nutrition) and IgY (Globigen Jump Start).

Figure 3 – Feed conversion rate. NC: negative group, PC: positive group, AGP: supplementation with AGP, AC/GJS: combination of PM (Activo, EW Nutrition) and IgY (Globigen Jump Start).

The multiple benefits of using IgY in piglet nutrition strategies are also highlighted by Rosa et al. (2015), Figure 4, and Prudius (2021).

Figure 4. Effect of treatments on the performance of newly weaned piglets. Means (±SEM) followed by letters a,b,c in the same group of columns differ (p < 0.05). NC (not challenged with ETEC, and diet with 40 ppm of colistin, 2300 ppm of zinc, and 150 ppm of copper). Treatments challenged with ETEC: GLOBIGEN® (0.2% of GLOBIGEN®); DPP (4% of dry porcine plasma); and PC (basal diet) (SOURCE: Rosa et al., 2015).

Conclusions

AGP removal and overall antibiotic reduction seems to be the only direction that the global swine industry must take for the future. From the front line, swine producers demand cost-effective AGP-free products that don’t compromise growth performance and animal health. Along with this demand, finding the best strategies for piglet nutrition in this scenario is critical in minimizing the adverse effects of weaning stress. With that in mind, alternatives such as egg immunoglobulins and phytomolecules are commercial options that are already showing great results and benefits, helping swine producers to go a step further into the future of swine nutrition.

References

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Pozzebon da Rosa, Daniele, Maite de Moraes Vieira, Alexandre Mello Kessler, Tiane Martin de Moura, Ana Paula Guedes Frazzon, Concepta Margaret McManus, Fábio Ritter Marx, Raquel Melchior and Andrea Machado Leal Ribeiro, “Efficacy of hyperimmunized hen egg yolks in the control of diarrhea in newly weaned piglets,” Food and Agricultural Immunology 26, no. 5 (2015): 622-634. https://doi.org/10.1080/09540105.2014.998639

Freitas Barbosa, Fellipe, Silvano Bünzen. Produção de suínos em épocas de restrição aos antimicrobianos–uma visão global. In: Suinocultura e Avicultura: do básico a zootecnia de precisão (2021): 14-33. https://dx.doi.org/10.37885/210203382

Correa-Fiz, Florencia, José Maurício Gonçalves dos Santos, Francesc Illas and Virginia Aragon, “Antimicrobial removal on piglets promotes health and higher bacterial diversity in the nasal microbiota,” Scientific reports 9, no. 1 (2019): 1-9. https://doi.org/10.1038/s41598-019-43022-y

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Davies, Madlen and Timothy R. Walsh, “A colistin crisis in India,” The Lancet. Infectious diseases 18, no. 3 (2018): 256-257. https://doi.org/10.1016/s1473-3099(18)30072-0

Castillo, Marisol, Susana M Martín-Orúe, Miquel Nofrarías, Edgar G Manzanilla and Josep Gasa, “Changes in caecal microbiota and mucosal morphology of weaned pigs”, Veterinary microbiology 124, no. 3-4 (2007): 239-247. https://doi.org/10.1016/j.vetmic.2007.04.026

Dyar, Oliver J, Jia Yin, Lilu Ding, Karin Wikander, Tianyang Zhang, Chengtao Sun, Yang Wang, Christina Greko, Qiang Sun and Cecilia Stålsby Lundborg, “Antibiotic use in people and pigs: a One Health survey of rural residents’ knowledge, attitudes and practices in Shandong province, China”, Journal of Antimicrobial Chemotherapy 73, no. 10 (2018): 2893-2899. https://doi.org/10.1093/jac/dky240

Prudius, T. Y., Gutsol, A. V., Gutsol, N. V., & Mysenko, O. O “Globigen Jump Start usage as a replacer for blood plasma in prestarter feed for piglets,” Scientific Messenger of LNU of Veterinary Medicine and Biotechnologies, Series: Agricultural sciences 23, no. 94 (2021): 111-116. https://doi.org/10.32718/nvlvet-a9420

Guevarra, Robin B., Jun Hyung Lee, Sun Hee Lee, Min-Jae Seok, Doo Wan Kim, Bit Na Kang, Timothy J. Johnson, Richard E. Isaacson and Hyeun Bum, “Piglet gut microbial shifts early in life: causes and effects,” Journal of animal science and biotechnology 10, no. 1 (2019): 1-10. https://dx.doi.org/10.1186%2Fs40104-018-0308-3

Waititu, Samuel M., Jung M. Heo, Rob Patterson and Charles M. Nyachoti, “Dose-response effects of in-feed antibiotics on growth performance and nutrient utilization in weaned pigs fed diets supplemented with yeast-based nucleotides,” Animal Nutrition 1, no. 3 (2015): 166-169. https://doi.org/10.1016/j.aninu.2015.08.007

Xiaoyu Li, Ying Yao, Xitao Wang, Yuhong Zhen, Philip A Thacker, Lili Wang, Ming Shi, Junjun Zhao, Ying Zong, Ni Wang, Yongping Xu. “Chicken egg yolk antibodies (IgY) modulate the intestinal mucosal immune response in a mouse model of Salmonella typhimurium infection,” International immunopharmacology 36, (2016) 305-314. https://doi.org/10.1016/j.intimp.2016.04.036

Yunsheng Han, Tengfei Zhan, Chaohua Tang, Qingyu Zhao, Dieudonné M Dansou, Yanan Yu, Fellipe F Barbosa, Junmin Zhang. Effect of Replacing in-Feed Antibiotic Growth Promoters with a Combination of Egg Immunoglobulins and Phytomolecules on the Performance, Serum Immunity, and Intestinal Health of Weaned Pigs Challenged with Escherichia coli K88. Animals 11, no. 5 (2021): 1292. https://doi.o

by Ruturaj Patil, Product Manager Phytogenic Liquids, EW Nutrition

Commercial poultry operations have undergone enormous changes in production practices over the last 50 years. Genetic selection for high production rates, along with upgraded management techniques and dietary measures, have led to increased performance standards in all poultry operations (Kogut et al., 2017). However, it is sensible to now look into whether poultry performance may soon reach a ceiling due to genetic and/or physiological limits. So, aiming at further performance optimization, poultry researchers and producers are now focusing on gut health.

Gut health management is key to sustainably improve poultry performance

The caveat, of course, is that, due to concerns about antimicrobial resistance, antimicrobial growth promoters (AGPs) no longer offer the easy answer to gut health issues they once were. To preserve antibiotics’ efficacy for cases where they are indispensable, gut health-oriented performance enhancement needs to come from other sources. This article reviews the principles of gut health management in poultry and shows how Activo liquid, a phytomolecules-based in-water solution, strengthens poultry performance by targeting gut health.

Gut health: the cradle of poultry performance

Gastrointestinal health in poultry birds encompasses three dimensions: microflora balance, gut structural integrity, and immune system status. The gut plays a vital and diverse role as it hosts most microorganisms in the body, contains more than twenty different hormones, digests and absorbs the nutrients, and accounts for 20% of body energy expenditure (Choct, 2021). When gut health is compromised, digestion and nutrient absorption are affected, with likely detrimental effects on feed conversion, followed by economic loss and greater disease susceptibility.  Disease resistance and nutrient utilization largely depend on maintaining a beneficial gut antioxidant status, improving gut integrity, and modulating the gut microbiota (Oviedo-Rondón, 2019).

In birds, the gut is separated into five distinct regions (Figure 1): crop, proventriculus, gizzard, small intestine (duodenum, jejunum, and ileum), and large intestine (ceca, cloaca, and vent). Each of these regions has a specific role in the secretion of digestive juices and enzymes, the grinding of feed particles and then the digestion and absorption of nutrients (Bailey 2019).

Figure 1: Schematic overview of poultry gastrointestinal tract

Factors affecting gut health

Gut health is influenced by the balance between the physiological health status of host, the gut microbiota, and a range of specific factors, all of which producers need to consider. From a management perspective, key factors encompass deprived gut health, biosecurity, and production stress, which is elevated during certain critical stages (see table 1). Environmental factors include humidity, temperature, and ventilation. Dietary factors, such as feed and water quality, feed composition, and mycotoxin contamination, also impact the development and ongoing state of poultry birds’ intestinal microbiota.

Table 1: Critical stages for gut health issues in poultry birds

The future is here: antibiotic reduction through improved gut health

There is a strong trend towards antibiotic-free (ABF) poultry production, fueled by AGP bans in certain regions (such as the European Union) and increasing consumer interest in avoiding products containing traces of AGPs. ABF systems can be profitable as long as the prices for the final ABF products can cover the investment costs necessary to produce these products. Larger-scale, sustainable ABF production will depend on developing a more profound understanding of intestinal health alongside the development of practical applications that foster gut health throughout each step of the production system.

Feed additive solutions to support birds during challenging situations

Feed additive manufacturers are looking into accessible alternatives to mitigate the need for antibiotics in ABF systems, requiring enormous research and development efforts. At EW Nutrition, our approach is to offer a holistic antibiotic reduction program for gut health management in poultry. The program comprises feed- and water-based solutions to support gut health during high-challenge periods. Activo liquid, an in-water solution containing standardized amounts of selected phytomolecules, is a key component of our program. Based on its three-fold mode of action, Activo liquid provides gut health support that improves livability and feed efficiency:

• Antimicrobial activity hinders the growth of potential pathogens
• Better gut integrity and positive microbiota optimize feed efficiency and gut health
• Antioxidant activity at the gut level prevent free radical formation and oxidative stress

As a water-based solution, Activo liquid provides a quick and flexible option for gut health control on poultry farms. The benefits of Activo liquid supplementation have been demonstrated through several scientific and field studies globally.

Activo liquid reduces mortality and improves feed conversion in broilers

Numerous field studies for antibiotic-free broilers across different countries and breeds show: on average, the inclusion of Activo liquid reduces mortality by 0.6% and improves FCR by 5%, compared to non-supplemented control groups (Figure 2).

Figure 2: Changes in livability and feed conversion rate in Activo liquid-supplemented broilers

Activo Liquid supports broiler breeders from start of lay to pre-peak production

Broiler breeders are prone to gut-related issues from the start of lay to pre-peak production (age 24 to 32 weeks). This period is characterized by sudden changes in feed consumption and high production stress. Field studies from Thailand show that Activo liquid supplementation in this phase leads to improved livability and higher laying rates.

A of 34,000 female broiler breeders during the first 9 weeks of production found that for the group receiving Activo Liquid  (200 ml / 1000 L, 5 days per week, 6 hours per day):

• The average laying rate/HH increased by 7.2 % during the trial period,
• Nearly 3  more  hatching  eggs  per  hen  housed  and  about  5  more  hatching  eggs  than  the  genetic standard were produced, and
• Mortality decreased by 0.2 % points compared to the control.

Another study, again evaluating the first 9 weeks of production using 20,000 birds, also found that broiler breeders supplemented with  Activo  Liquid show reduced mortality, a higher laying rate, and more hatching eggs per hen housed (Figure 3).

Figure 3: Performance results from Cobb broiler breeders, Activo liquid supplementation vs. control

Activo program improves layer productivity

Commercial layers often becomes challenged due to stress originating from management issues, gut pathogens, and an improper assimilation of nutrients. The negative impact on gut health can result in poor uniformity, low livability, and impaired body weight gain. The Activo program (a combination of Activo powder and liquid) has been found to improve layer performance, likely because its phytogenic components foster better intestinal integrity and microbiome diversity.

A study of 8 replicates with 36 Hy-line brown laying hens was conducted in China, for instance, testing the inclusion of both Activo (100 g / MT of feed) and Activo Liquid (250 ml / 1000 L for 4 days, every 2 weeks, from week 15 to week 25). It found that the Activo program  can effectively support the animals in coping with NSP-rich diets (Figure 4). Supplemented layers showed 3.36% higher egg production, representing more than 3.5 eggs and more than 150 grams of additional egg mass per hen housed during the period.  Better  gut  health  in  the  Activo  Program  gut  was evidenced  by  a  better  hen  body  weight ,  as  well  as  higher  yolk  color, lower  FCR, and improved  intestinal morphology parameters.

Figure 4: Performance results from Hy-line layers, Activo program vs. control

Conclusion: future improvements in poultry performance will come from the gut

As the trend towards ABF poultry production gains momentum, a concerted focus on supporting birds’ gut health is key to achieving optimal performance. Multiple field studies of Activo liquid application demonstrate that, due to their antimicrobial and antioxidant properties, the phytomolecules present in Activo liquid effectively support birds’ intestinal health during challenging periods.

In combination with good dietary, hygiene and management practices, phytomolecules offer a potent tool for reducing the use of antibiotics. The inclusion of Activo liquid in their birds’ diets allows poultry producers to achieve better gut health and, thus, stronger performance results in a sustainable way.

References

Bailey, Richard A. “Gut Health in Poultry: the World within – Update.” The Poultry Site, July 6, 2021. https://www.thepoultrysite.com/articles/gut-health-in-poultry-the-world-within-1.

Choct, Mingan. “The Importance of Managing Gut Health in Poultry.” Poultry Hub Australia, November 26, 2014. https://www.poultryhub.org/importance-managing-gut-health-poultry.

Kogut, Michael H., Xiaonan Yin, Jianmin Yuan, and Leon Bloom. “Gut Health in Poultry.” CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources 12, no. 031 (October 1, 2017): 1–7. https://doi.org/10.1079/pavsnnr201712031.

Oviedo-Rondón, Edgar O. “Holistic View of Intestinal Health in Poultry.” Animal Feed Science and Technology 250 (2019): 1–8. https://doi.org/10.1016/j.anifeedsci.2019.01.009.

by Inge Heinzl, Editor, and Technical Team, EW Nutrition

What is your most crucial key feed performance indicator? We posted this question on an online professional platform and got more than 330 answers from professionals in the industry:

• 55 % of the respondents considered feed efficiency or feed conversion rate (FCR) the key indicator, and
• 35 % listed feed cost / kg produced as their most important indicator.

As feed represents 60-70 % of the total production costs, feed efficiency has a high impact on farm profitability – especially in times of high feed prices. Furthermore, for the meat industry, an optimal FCR is essential for competitiveness against other protein sources. Finally, for food economists, feed efficiency is connected to the optimal use of natural resources (Patience et al., 2015).

In this article, we explain the factors that influence feed efficiency and show options to support animals in optimally utilizing the feed – directly improving the profitability of your operation.

How to measure the feed conversion rate

The FCR shows how efficiently animals utilize their diet for maintenance and net production. In the case of fattening animals, it is meat production; for dairy cows, it is milk, and for layers, it is egg mass (kg) or a specific egg quantity.

The feed conversion rate is the mathematical relation obtained by dividing the amount of feed the animal consumed by the production it provided. The FCR is an index for the degree of feed utilization and shows the amount of feed needed by the animal to produce one kg of meat or egg mass, or, e.g., 10 eggs.

When comparing the FCRs of different groups of animals (e.g., from different houses or farms), some considerations are important:

• Feed consumed is not feed disappeared: Due to differences in feeder design and feeder adjustment, these two values can differ by 10-30 %. If FCR is calculated for economic purposes, the wasted feed must be included, as it causes costs and must be paid by the farmer. However, if FCR is calculated for scientific purposes (e.g., a performance trial), only the feed consumed should be included.
• Even if they are same-aged animals, individuals or groups differ in weight. Hence, they have different requirements for maintenance and also diverging quantity left for production. To avoid mistakes, weight-corrected FCR can be used.
• Nutrient utilization also depends on genotype and sex; thus, comparisons should consider these factors as they also influence weight gain and body composition (Patience et al., 2015).

Many factors influence the FCR

There are internal and external factors that influence feed efficiency. Internal factors originate in the animal and include genetics, age, body composition, and health status. In contrast, external factors include feed composition, processing, and quality, as well as the environment, welfare enrichment, and social aspects.

1. Species

Different species have different body sizes and physiology and, therefore, vary in their growth and maintenance requirements, impacting their efficiency in converting the feed.

Table 1: FCRs of different species

Compared to terrestrial animals, for example, fish and other aquatic animals have a low FCR. Being poikilothermic (animals whose body temperature ranges widely), they don’t spend energy on maintaining their body temperature if the surrounding water is within their optimal range. As they are physically supported by water, they also need less energy to work against gravity. Furthermore, carnivorous fish are offered highly digestible, nutrient-dense feed, which lowers their requirements in quantity. Omnivorous fish, on the other hand, also consume feedstuffs not provided by the producer (e.g., algae and krill), which is not considered in the calculation. Broilers are the only farm animals achieving a similar FCR.

2. Sex, age, and growth phase

Sex determines gene expression related to the regulation of feed intake and nutrient utilization. Males have a better feed conversion and put on more lean meat than females and castrates, which grow slower and easier run to fat.

Young animals have a fast growth rate and are offered nutritionally dense feed; hence, their FCR is lower. When the animal grows and gains weight, its energy requirement for maintenance increases and its growth rate and the feed nutrient density diminish.

Table 2: FCR during different life phases of pigs (based on Adam and Bütfering, 2009)

3. Health and gut health

Health decisively impacts feed conversion. An animal that is challenged by pathogens reduces its feed intake and, thus, decreases growth. Additionally, the body needs energy for the immune defense, the replacement of damaged or lost tissue, and heat production, in case of fever. As many immune components are rich in protein, this is the first nutrient to become limited.

An imbalance in the gut microbiome also impacts feed conversion: pathogenic microorganisms damage tissues, impair nutrient digestion and absorption, and their metabolic products are harmful. Furthermore, pathogens consume nutrients intended for the host and continue to proliferate at its expense.

4. Environment

The environment influences the way the animals spend their maintenance energy. According to Patience (2012), when a 70 kg pig is offered feed ad libitum, 34 % of the daily energy is used for maintenance. For each °C below the thermoneutral zone, an additional 1.5% of feed is needed for maintenance. In heat stress, each °C above the optimum range decreases feed intake by 2%. Therefore, the feed needs to be denser to fulfill the requirement, or the animal will lose weight. Social stress also influences animal performance, especially chronic stress situations. Keeping the animals in their thermoneutral zone and mitigating the impact of stressors means more energy can go towards performance.

5. Feed quantity, composition, and quality

The feed is the source of nutrients animals convert into production. So, it’s natural that its quality and composition, and the availability of nutrients affect feed efficiency.

Better FCR by increasing nutrient density and digestibility

Higher energy content in the diet and better protein digestibility improve FCR. Saldaña et al. (2015) assert that increasing the energy content of a diet led to a linear decrease of the average daily feed intake but improved FCR quadratically. The energy intake by itself remained equal. However, these diet improvements also increase costs, and a cost-benefit analysis should be conducted.

Feed form and particle size play an important role

Feed processing can improve nutrient utilization. Particle size, moisture content, and whether the feed is offered as pellets or mash influence feed efficiency. Reducing the particle size leads to a higher contact surface for digestive enzymes and higher digestibility. Chewning et al. (2012) tested the effect of particle size and feed form on FCR in broilers. They found that pellet diets enable better FCRs than mash diets – one reason is the lower feed waste, another one the smaller feed particle size in the pelleted feed. Comparing the different tested mash diets, the birds receiving feed with a particle size of 300 µm performed better than the birds getting a diet with 600 µm particles.

Richert and DeRouchey (2015) show that pigs’ feed efficiency improved by 1.3 % for every 100 µm when the particle size was reduced from 1000 µm to 400 µm , as the contact surface for the digestible enzymes increased. In weaning piglets of 28-42 days, the increase of particle size from 394 µm to 695 µm worsened FCR from 1.213 to 1.245 (Almeida et al., 2020). There is a flipside to smaller particle size as well, however: high quantities of fines in the diet can lead to stomach ulceration in pigs (Vukmirović et al., 2021).

Non-starch polysaccharide (NSP)-rich cereals worsen FCR

The carbohydrates in feedstuffs such as wheat, rye, and barley are not only energy suppliers, and if not managed well, the inclusion of these raw materials can deteriorate feed conversion. Vegetable structural substances such as cellulose, hemicellulose, or lignin (e.g., in bran), are difficult or even impossible to utilize as they lack the necessary enzymes.

Figure 1: Contents of arabinoxylan and ß-glucan in grain (according to Bach Knudsen, 1997)

Additionally, water-soluble NSPs (e.g., pectins, but also ß-glucans and pentosans) have a high water absorption capacity. These gel-forming properties increase the viscosity of the digesta. High viscosity reduces the passage rate and makes it more difficult for digestive enzymes and bile acids to come into contact with the feed components. Also, nutrients’ contact with the resorptive surface is reduced.

Another disadvantage of NSPs is their “cage effect.” The water-insoluble NSPs cellulose and hemicellulose trap nutrients such as proteins and digestible carbohydrates. Consequently, again, digestive enzymes cannot reach them, and they are not available to the organism.

Molds and mycotoxins impair feed quality, but also animal health

Molds reduce the nutrient and energy content of the feed and negatively impact feed efficiency. They are dependent on active water in the feed and feed ingredients. Compared to bacteria, which need about 0.9-0.97 Aw (active water), most molds require only 0.86 Aw.

Table 3: Comparison of 28-day-old chicks performance fed not-infested and molded corn

Besides spoiling raw materials and feed and reducing their nutritional value, molds also produce mycotoxins which negatively impact animal health, including gut health. They damage the intestinal villi and tight junctions, reducing the surface for nutrient absorption. In a trial with broiler chickens, Kolawole et al. (2020) showed a strong positive correlation between the FCR and the exposure to different mycotoxins. The increase in levels of toxin mixtures resulted in poor FCR. Williams and Blaney (1994) found similar results with growing pigs. The animals received diets containing 50 % and 75 % of corn with 11.5 mg nivalenol and 3 mg zearalenone per kg. The inclusion of contaminated corn led to a deterioration of feed efficiency from 2.45 (control) to 3.49 and 3.23.

Oxidation of fats also affects feed quality

DDGS (distiller’s dried grains with solubles), by-products of corn distillation processes, are often used as animal feed, especially for pigs. The starch content is depleted in the distillation process and thus removed. The fat, however, is concentrated, and DDGS reach a similar energy content as corn.

Pigs also receive fats from different sources (e.g., soybean or corn oil, restaurant grease, animal-vegetable blends), especially in summer. Due to heat, the animals eat less, so increasing energy density in the feed is a possibility to maintain the energy intake.  The high fat content, however, makes these feeds susceptible to oxidation at high temperatures.

The oxidation of feedstuffs manifests in the rancidity of fats, destruction of the fat-soluble vitamins A, D, and E, carotenoids (pigments), and amino acids, leading to a lower nutritional value of the feed.

Use adequate supplements to enhance FCR

The feed industry offers many solutions to improve the FCR for different species. They usually target the animal’s digestive health or maintain/enhance feed quality, including increasing nutrient availability.

1. Boost your animals’ gut health

Producers can improve gut health by preventing the overgrowth of harmful microorganisms and by mitigating the effects of harmful substances. For this purpose, two kinds of feed additives are particularly suitable: phytomolecules and products mitigating the impact of toxins and mycotoxins.

Phytomolecules help stabilize the balance of the microbiome

By preventing the proliferation of pathogens, phytomolecules help the animal in three ways:

1. They prevent pathogens from damaging the gut wall
2. They deter and mitigate inflammation
3. By inhibiting the overgrowth of pathogens, they promote better nutrient utilization by the animal

Only a healthy gut can optimally digest feed and absorb nutrients.

In trials testing the phytogenic Activo product range, supplemented animals showed the following FCR improvements compared to non-supplemented control groups (Figure 2).  Note that phy­tomolecules also have a digestive effect that contributes to the FCR improvements:

Figure 2: FCR improvements for animals receiving Activo

Products mitigating the adverse effects of toxins

Both mycotoxins and bacterial toxins negatively impact gut health. Mycotoxins are ingested with the feed; bacterial toxins appear when certain bacteria proliferate in the gut, e.g., gram-negative bacteria releasing LPS or Clostridium perfringens producing NetB and Alpha-toxin.

Products that mitigate the harmful effects of toxins help to protect gut health and maintain an optimal feed efficiency, as shown with a trial conducted with Mastersorb Gold:

Table 4: Trial design, the impact of Mastersorb Gold on broilers challenged with zearalenone and DON-contaminated feed

Figure 3: Average FCR for broilers, with or without zearalenone and DON challenge, with or without Mastersorb Gold supplementation

2. Improve nutrient utilization

Maximum use of the nutrients contained in the feed can be obtained with the help of feed additives that promote digestion. Targeting the animal, selected phytomolecules are used for their digestive properties. Focusing on the feed, specific enzymes can unlock nutrients and thus improve feed efficiency.

Phytomolecules support the animal’s digestive system

Phytomolecules promote optimal digestion and absorption of nutrients by stimulating the secretion of digestive juices, such as saliva or bile, enhancing enzyme activity, and favoring good GIT motility (Platel and Srinivasan, 2004). FCR improvements thanks to the use of a phy­tomolecules-based product (Activo) are shown in figure 2.

Enzymes release more nutrients from feed

Enzymes can degrade arabinoxylans, for example. Arabinoxylans are the most common NSP fraction in all cereals – and are undigestible for monogastric animals. Enzymes can make these substances available for animals, allowing for complete nutrient utilization.  Additionally, nutrients trapped due to the cage effect are released, altogether increasing the energy content of the diet and improving FCR.

3. Be proactive about preserving feed quality

The quality of feed can deteriorate, for instance, when nutrients oxidize, or mold infestation occurs. Oxidation by-products promote oxidative stress in the intestine and may lead to tissue damage. Molds, in turn, take advantage of the nutrients contained in the feed and produce mycotoxins. Both cases illustrate the importance of preventing feed quality issues. Feed additives such as antioxidants and mold inhibitors mitigate these risks.

Antioxidants prevent feed oxidation

Antioxidants scavenge free radicals and protect the feed from spoilage. In animals, they mitigate the adverse effects of oxidative stress. Antioxidants in pig nutrition can stabilize DDGS and other fatty ingredients in the feed, maintaining nutrient integrity and availability. Figure 4 shows the FCR improvement that a producer in the US obtained when using the antioxidant product Santoquin in pork finisher diets containing 30% DDGS.

Figure 4: FCR improvement in pigs receiving Santoquin (trial with a Midwest pork producer)

In DDGS-free diets, which are more common in poultry production, antioxidants also help optimize FCR, as shown by the results of a comprehensive broiler field study in 2015 (figure 5).

Figure 5: FCR in broilers receiving Santoquin, compared to a non-supplemented control group

Inhibiting molds and keeping feed moisture

To round off the topic of feed quality preservation, one should consider mold inhibitors, which also play an essential role. Used at the feed mill, these products blend two types of ingredients with their different modes of action: surfactants and organic acids. Surfactants bind active water so that the moisture of the feed persists, but fungi cannot survive. Organic acids, on the other hand, have anti-fungal properties, directly acting against molds. Both actions together prevent the reduction of energy in the feed, keeping feed efficiency at optimal levels.

Conclusion

The improvement of feed efficiency ranks as one of the most, if not the most, critical measures to cope with rising feed costs. By achieving optimal nutrient utilization, producers can make the most out of the available raw materials.

The feed industry offers diverse solutions to support animal producers in optimizing feed efficiency. Improving gut health, mitigating the negative impact of harmful substances, and maintaining feed quality are crucial steps to achieving the best possible FCR and, hence, cost-effective animal production.

References

Adam, F., and L. Bütfering. “Wann Müssen Meine Schweine an Den Haken?” top agrar. top agrar online, October 1, 2009. https://www.topagrar.com/schwein/aus-dem-heft/wann-muessen-meineschweine-an-den-haken-9685161.html.

Almeida, Leopoldo Malcorra, Vitor Augusto Zavelinski, Katiucia Cristine Sonálio, Kariny Fonseca da Silva, Keysuke Muramatsu, and Alex Maiorka. “Effect of Feed Particle Size in Pelleted Diets on Growth Performance and Digestibility of Weaning Piglets.” Livestock Science 244 (2021). https://doi.org/10.1016/j.livsci.2020.104364.

Chewning, C.G., C.R. Stark, and J. Brake. “Effects of Particle Size and Feed Form on Broiler Performance.” Journal of Applied Poultry Research 21, no. 4 (2012): 830–37. https://doi.org/10.3382/japr.2012-00553.

Gaines, A. M., B. A. Peerson, and O. F. Mendoza. “Herd Management Factors That Influence Whole Feed Efficiency.” Essay. In Feed Efficiency in Swine, edited by J. Patience, 15–39. Wageningen Academic, 2012.

Kolawole, Oluwatobi, Abigail Graham, Caroline Donaldson, Bronagh Owens, Wilfred A. Abia, Julie Meneely, Michael J. Alcorn, Lisa Connolly, and Christopher T. Elliott. “Low Doses of Mycotoxin Mixtures below EU Regulatory Limits Can Negatively Affect the Performance of Broiler Chickens: A Longitudinal Study.” Toxins 12, no. 7 (2020): 433. https://doi.org/10.3390/toxins12070433.

Patience, J. F. “The Influence of Dietary Energy on Feed Efficiency in Grow-Finish Swine.” Essay. In In Feed Efficiency in Swine, edited by J. Patience, 15–39. Wageningen Academic, 2012.

Patience, John F., Mariana C. Rossoni-Serão, and Néstor A. Gutiérrez. “A Review of Feed Efficiency in Swine: Biology and Application.” Journal of Animal Science and Biotechnology 6, no. 1 (2015). https://doi.org/10.1186/s40104-015-0031-2.

Platel, K., and K. Srinivasan. “Digestive Stimulant Action of Spices: A Myth or Reality?” Indian J Med Res, pp 167-179 119 (May 2004): 167–79. http://www.ncbi.nlm.nih.gov/pubmed/15218978

Richert, B. T., and J. M. DeRouchey. “Swine Feed Processing and Manufacturing.” Pork Information Gateway, September 14, 2015. https://porkgateway.org/resource/swine-feed-processing-and-manufacturing/.

Saldaña, B., P. Guzmán, L. Cámara, J. García, and G.G. Mateos. “Feed Form and Energy Concentration of the Diet Affect Growth Performance and Digestive Tract Traits of Brown-Egg Laying Pullets from Hatching to 17 Weeks of Age.” Poultry Science 94, no. 8 (2015): 1879–93. https://doi.org/10.3382/ps/pev145.

Vukmirović, Đuro, Radmilo Čolović, Slađana Rakita, Tea Brlek, Olivera Đuragić, and David Solà-Oriol. “Importance of Feed Structure (Particle Size) and Feed Form (Mash vs. Pellets) in Pig Nutrition – A Review.” Animal Feed Science and Technology 233 (2017): 133–44. https://doi.org/10.1016/j.anifeedsci.2017.06.016.

by Technical Team, EW Nutrition

The world demand for milk has seen a sharp rise. Today, we have just over 1 billion dairy cows in the world producing about 1.6 billion tons of milk per year. However, OECD and FAO estimate that numbers will rise up to 1.5 billion dairy cows in 2028, for a total milk production of 2 billion tons . This increase will come at a tremendous cost in terms of global warming: Each day, dairy cows can produce 250 to 500 litres of methane, a powerful greenhouse gas (Johnson and Johnson, 1995).

Climate change is not the only reason for zootechnical production to adopt methane reduction strategies. Methane emissions represent an important energy loss for dairy cows, which negatively impacts production performance. In this article, we review why methanogenesis in dairy cows arises, and how the use of phytogenic product Activo Premium can help achieve efficient energy use and reduced climate impact.

Less methane: environmental, regulatory, and business pressures

Methane (CH₄) is considered one of the gases that, together with CO₂ (carbon dioxide) and N₂O (nitrous oxide), traps heat in the atmosphere and, thus, causes global warming. While methane is generated in multiple industries, including the energy and waste sectors, much of the methane present in the atmosphere derives from livestock activities and, in particular, from ruminant farms.

About 28% of total methane emissions derive from agriculture sector and enteric fermentations (digestive processes in which feed is broken down by microorganisms) are responsible for about 65% of the total methane coming from zootechnical sector (Knapp et al., 2014). For this reason, in recent years, strategies for mitigating methane emissions in dairy cows have aroused great interest among researchers and environmentally-conscious consumers.

Regulators have also caught on: In October 2020, the European Commission presented its strategy for reducing methane emissions in Europe. Reductions are essential to achieve the Commission’s climate objectives for 2030 and climate neutrality by 2050. For the livestock sector, the Commission seeks to develop an inventory of innovative mitigating practices by the end of 2021, with a special focus on methane from enteric fermentation.

Uptake of mitigation technologies will be promoted though Member States’ and the Common Agricultural Policy’s “carbon farming” measures. Carbon-balance calculations at farm level are to be encouraged through digital tools; and the Horizon Europe strategic plan 2021-2024 will likely include targeted research on effective reduction strategies, focusing on technology, dietary factors, and nature-based solutions such as phytogenic products.

Even aside from environmental concerns, consumers demands, and regulatory steps, there is a critical business case for dairy producers to lower methane emissions. Given the ever-increasing global demand for dairy products, farmers and other operators in the sector more than ever try to maintain and indeed improve production to maximize yields, both economically and in terms of finished products. Problematically, methane production in the rumen represents a great loss of energy for the animal.

On average, about 6% of the total energy ingested by a dairy cow is transformed into methane, every single day (Succi and Hoffmann, 1993). The less methane a cow produces, the more metabolizable energy (ME) she gets out of her gross energy (GE) intake. A better ME/GE ratio translates into higher net energy of lactation (NEl). Energy losses from methanogenesis thus directly decrease the energy nutritionist can consider as usable during rationing.

Before we review the current research on how an adequate manipulation of the diet and of the rumen environment can mitigate these energy losses, we need to ask ourselves, why is methane formed in the rumen at all?

Animal physiology: how methane is formed in the rumen

Ruminants’ digestion of vegetal ingredients is linked to their rumen’s symbiotic bacterial, protozoan, and fungal flora. This microbiota has all the enzymatic properties necessary for the digestion (or rather pre-digestion) of ingested forage, including some cellulose fractions that monogastric animals cannot use.

In the rumen, the main products deriving from bacterial fermentation are volatile fatty acids and methane. The main volatile fatty acids are acetic acid, propionic and butyric acid, which are mainly absorbed and used by the animal. Meanwhile, methane helps to maintain the oxidative conditions in the rumen’ anaerobic environment, but also represents an energy loss (Czerkawski, 1988).

Methanogenesis is carried out by methanogenic bacteria and archae in the rumen (Guglielmelli, 2009). They use molecular hydrogen and carbon dioxide as a substrate for the synthesis of methane, according to the following equation:

4 H₂ + CO₂ → CH₄ + 2 H₂O

A few other chemical reactions contribute to methanogenesis, but they all have one thing in common: they require hydrogen ions in the rumen fluid to form methane from CO₂. This gives us the first “point of attack” for reducing methane formation: the diet.

Increase the share of propionic acid

Propionic acid is in competition with methanogens in using hydrogen ions to reduce glucose molecules:

C₆H₁₂O₆ (glucose) + 4 H → 2 C₃H₆O₂ (propionic) + 2 H₂O

It is clear that if propionic fermentations are stimulated through the diet at the expense of the pathways leading to acetate and butyrate (where hydrogen ions are transferred to the rumen environment), the availability of hydrogen for the reduction of CO₂ by methanogenic bacteria decreases.

Diets with a high level of concentrates, and low levels of neutral detergent fibre, yield more propionic acid and less acetic and butyric acid. Set aside lower methane emissions, this increase in energy is desirable during peak lactation: the energy gap that follows from the decrease in ingestion by the animal requires diets with a high amount of substrate for gluconeogenesis. Furthermore, the greater production of propionate sequesters H₂ in the rumen environment and, consequently, less CO₂ is reduced to methane.

Optimize the protozoa count

Most methane-producing bacteria live in symbiosis with most of the protozoan species, they are located on the surface of the protozoan. It follows that optimizing the population of protozoa present in the rumen (through dietary measures) leads to a lower methanogenesis (Patra and Saxena, 2010). Naturally, a minimum amount of protozoa must be maintained to avoid excessively reducing ruminal motility (regular contractions that mix and move the rumen content), which is important for feed digestibility.

Diet is not enough: feed additives to reduce methane production

Dietary measures alone cannot considerably reduce daily methane production. In the past, antibiotic growth promoters belonging to the ionophores family were commonly administered in the EU. These antibiotics increase efficiency and daily weight gain by promoting gluconeogenesis through greater production of propionic acid in the rumen and a consequent reduction in emitted methane (Piva et al., 2014).

The emergence of bacterial forms resistant to growth-promoting antibiotics have forced the EU to ban these molecules to safeguard consumer health. Fortunately, certain feed additives can also help reduce methanogenesis and generate energy saving – without the danger of resistance.

Secondary plant extracts or phytomolecules feature relevant properties, including bactericidal, virucide, and fungicide effects. As we have seen, it is critical to encourage certain fermentations at the expense of others and possibly reduce the organisms directly and indirectly responsible (bacteria and protozoa) for methanogenic fermentations.

Activo Premium: reduce methane and preserve energy

Phytogenic product Activo Premium contains a targeted phytomolecules mix capable of influencing the rumen microbiome in this manner:

Figure 1: Anti-methanogenic properties of selected phytomolecules. Based on Lourenço et al. (2008) and Supapong et al. (2017)  

Activo Premium is a blend of phytomolecules that maximizes production results for both high- and low-energy diets. Studies show that Activo Premium’s effects on the on the rumen microbiome reduce the ratio of acetic to propionic and butyric acid and decrease the energy losses due to methane production.

Field trial: Activo Premium improves rumen fermentation processes

A trial at the University of São Paul, Brazil, sought to evaluate the impact of Activo Premium on rumen fermentation and methane emissions. Nine rumen-cannulated sheep (55 ± 3.7 kg of body weight) were divided into 3 groups, and randomly distributed in a triple 3×3 Latin square design. The animals were fed their experimental diets for 22 days (the sampling period) in the following 3 set-ups: one control group (basal diet without additives); one group receiving a basal diet with 200 mg of Activo Premium per kg of dry matter intake; and one group receiving a basal diet with 400 mg of Activo Premium per kg of dry matter intake.

Figure 2: Ratio of acetate to propionate (p = 0.03)

Figure 3: Protozoa count (p = 0.06; x 10⁵ / ml) and methane production (p < 0.01; l per kg of dry matter). Based on Soltan et al. (2018)

As shown in figures 2 and 3, Activo Premium favourably modifies the ratio of volatile fatty acids and reduces the protozoa count, which, as to be expected, results in reduced methane emissions.

Rumen simulation trial: the more Activo Premium added, the less methane produced

A trial was conducted at the University of Hohenheim (Germany) sought to evaluate the methane-reducing effects of different inclusion rates of Activo Premium, using a continuous long-term rumen simulation technique (Rusitec). Four different inclusion levels of Activo Premium (0, 2.1, 4.2, and 8.4 mg/d) were added to a diet with a ratio of concentrates to roughages of 80% to 20%, respectively.

Five consecutive Rusitec runs with one replication of each of the four inclusion schedules were performed. The run lasted for 14 days; 7 days were used for adaptation and the later 7 days for sampling. The fermenters were heated to 39°C. During the sampling period, total gas production and methane concentration of the total gas produced were measured every 24 h.

Figure 4: Methane emission (ml / day) for increasing inclusion rates of Activo Premium

In this trial with a rumen simulation system, Activo Premium significantly reduced methane volume (Figure 4): from 231 ml/d for the diet without any Activo Premium to 172 ml/d for the highest inclusion rate of Activo Premium.

Activo Premium: reduce methane emissions, support your profits and our planet

Both in vivo and in vitro trials have shown with high statistical reliability that Activo Premium can positively modulate rumen fermentations. The strategic combination of phytomolecules appears highly effective as a natural dietary supplementation option to modulate ruminal fermentation and decrease methane emissions. Adding Activo Premium to dairy cows’ diet will likely contribute significantly to reducing their methane emissions and optimizing their energy balance – improving animal performance while curbing the climate change impact, a win-win for everyone.

References

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Guglielmelli, Antonietta (2009) Studio sulla produzione di metano nei ruminanti: valutazione in vitro di alimenti e diete. [Tesi di dottorato] (Unpublished) http://www.fedoa.unina.it/3960/

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Piva, Jonatas Thiago, Jeferson Dieckow, Cimélio Bayer, Josiléia Acordi Zanatta, Anibal de Moraes, Michely Tomazi, Volnei Pauletti, Gabriel Barth, and Marisa de Piccolo. “Soil Gaseous N2O and CH4 Emissions and Carbon Pool Due to Integrated Crop-Livestock in a Subtropical Ferralsol.” Agriculture, Ecosystems & Environment 190 (2014): 87–93. https://doi.org/10.1016/j.agee.2013.09.008

Soltan, Y.A., A.S. Natel, R.C. Araujo, A.S. Morsy, and A.L. Abdalla. “Progressive Adaptation of Sheep to a Microencapsulated Blend of Essential Oils: Ruminal Fermentation, Methane Emission, Nutrient Digestibility, and Microbial Protein Synthesis.” Animal Feed Science and Technology 237 (March 2018): 8–18. https://doi.org/10.1016/j.anifeedsci.2018.01.004.

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