Biosecurity is the foundation for disease prevention. It includes all measures to reduce the risk of introduction and spread of infectious agents, using our knowledge of disease transmission processes.

Biosecurity is all the more important in antibiotic reduction scenarios: consistently high biosecurity standards can contribute substantially to the reduction of antimicrobial resistance, by preventing the introduction of resistance genes to the farm, and also by lowering the need for antimicrobials.

Higher biosecurity, lower use of antimicrobials

Laanen et al. (2013) studied the profile of swine farmers across Europe, finding a relation between a high level of internal biosecurity, an efficient control of infectious diseases, and a reduced need for antimicrobials.

In another study, Gelaude et al. (2014) examined Belgian broiler farms, concluding that antimicrobial use could be reduced by almost 30% when biosecurity and other farm issues were improved within a year. Collineau et at. (2017) studied swine farms in Belgium, France, Germany and Sweden. On average, antimicrobial use dropped by 47% – but farms with higher biosecurity compliance and a holistic approach (e.g. management and nutrition changes) needed even fewer antimicrobials.

Interventions pay off

Of course, the interventions necessary to achieve an increased level of biosecurity carry some costs. However, such interventions, especially if combined with better management of newborn animals and nutritional improvements, also strengthen productivity.

The same studies, which report that biosecurity improvements decrease antimicrobial use, also report stronger animal performance. For broilers, Laanen et al.  (2013) found a reduction of 0.5 percentage points in mortality and one point in FCR. For pigs, Collineau et al. (2017) found an improvement during both the pre-weaning and the fattening period of 0.7 and 0.9 percentage points, respectively.

Execution is a challenge

Biosecurity is considered the cheapest and most effective intervention in antibiotic reduction programs, but compliance is often difficult to achieve and thus low. It sounds simple: stop the introduction and spread of diseases.

However, in practice, this involves adopting a new set of attitudes and behaviors across all animal production and care activities. Measures should not be constraints, but part of a holistic process to improve the health of animals and people, to reduce antibiotics and boost performance.

Best practices

If you want to design a biosecurity program or improve an existing one, consider these three factors:

1. Know your menace
   Identify and prioritize the disease agents of greatest concern to the facility, focusing on the processes that carry a risk of pathogen entrance and spread, and are frequently repeated. Additionally, consider the size of the facility – more animals means higher risk.

2. Know your place
   Define the status quo, ideally using external questionnaires or audits (e.g. BioCheck UGent). This helps you identify and gaps in your biosecurity plan. Measures need to be based on the principles of separation (between high and low-risk animals and areas) and reduction (lower the infection pressure).

3. Know your processes
   An exhaustive evaluation of the daily farm practices – e.g. the movement of personnel, equipment and visitors, and or used litter management – will help you find weak spots so you can eliminate, prevent, or minimize the potential of disease.

The bottom line

Biosecurity measures are the basis for disease prevention in any profitable animal production system. Preventing the entrance and spread of disease pays off through performance improvements and lower antimicrobial use. Taking this to the next level, where biosecurity compliance complements improvements in management, health, and nutrition, sets your production up for long-term success.

By Marisabel Caballero and Fellipe Freitas Barbosa

References are available on request.

Older laying birds are still a valuable asset, as long as they are managed for performance and productivity. Eggshell quality is one of the elements that, without proper management, can quickly deteriorate. It is therefore essential that the egg producer takes into account all the necessary elements for the formation of high-quality eggs.

The eggshell, in a nutshell

The eggshell represents ten percent of the entire egg, by weight[i]. For instance, a 60-gram egg contains approximately 6 g of shell. Out of this particular shell, approximately 95% is CaCO₃[ii], with a total of 2.3 g of Calcium (Ca).

But where does the calcium in the eggshell come from?

The Ca required for the eggshell is obtained, in variable proportions, directly from the feed or water additives (absorbed from the gut and transported via the blood to the shell gland), or from the bone (resorbed by osteoclasts and the Ca transported to the blood to the shell gland).

Maintaining eggshell quality and bone calcium: Mission Impossible?

Eggshell quality is often negatively correlated to bone strength[iii], most probably because body calcium is redirected to the shell to the detriment of the bones and the other way around. This impacts the long-term health of the skeleton; however, modern laying hens can maintain shell quality while preserving bone mineralization[iv].

60 to 75% of shell Ca is derived from the diet on shell-forming days

Approximately 60 to 75% of shell Ca is derived directly from the diet on shell-forming days[v]. This means that the greater the proportion of Ca coming directly from the feed or water additives, the better the eggshell quality can be. Therefore, the factors that can improve shell quality will also reduce the need to mobilize bone Ca and can also help to maintain skeletal health.

In old laying birds, generally after peak production, the ability to deposit Ca onto the shell remains relatively constant[vi], so an increase in egg size after peak production will tend to result in reduced shell quality. Dietary requirements for Ca tend to increase and those for phosphorus (P) tend to decrease as hens age.

Also, as hens age, the efficiency of Ca metabolism decreases[vii]. Increases in dietary Ca and a widening of the Ca:available P ratio are intended to counter this issue. Excess dietary P can also reduce shell quality[viii].

Because of its importance in Ca and P absorption from the gut, adequate dietary vitamin D activity must also be provided[ix]. Feeding of the vitamin D metabolite 25-OH vitamin D3 can help to maintain skeletal and shell quality in high-producing laying hens[x].

Ca metabolism is a complex game

Ca metabolism is regulated by various hormones such as calcitonin, 1,25-dihydroxyvitamin D3 (calcitriol), and parathyroid hormone. Estrogen, androgens, and prostaglandins also appear to have an important role in avian Ca metabolism.

Source: Ricardo (2008)

Egg formation and Ca requirements

Source

A hen ovulates approximately 15 to 75 minutes following oviposition[xi], and the ovum takes approximately 4.25 hours to reach the shell gland[xii], at which point calcification takes approximately 17 hours[xiii]. Hens generally lay eggs in the morning and early in the afternoon[xiv]. The hen can use the Ca and P made available through diet to recover medullary bone losses during the next 5 hours after oviposition.

Once the ovum reaches the shell gland, the demand for calcium naturally increases greatly as eggshell formation progresses. The highest eggshell mineral accretion takes place 5 – 15 hours after the egg enters the shell gland[xv], which normally happens later in the afternoon and during the night preceding egg laying.

Hourly Ca requirements for eggshell calcification

Ca dietary requirements vary with species, age, breeding status, and dietary levels of vitamin D. Egg-laying birds and growing birds require more Ca than adult non-breeding birds.

Common eggshell quality problems and causes

In many cases, the source of eggshell problems can be detected by recognizing the specific markers. For instance, cracked, soft-shelled or corrugated eggs can be caused by saline water, or the impact of mycotoxins; shell-les eggs can be caused by improper amounts of Ca, P, Mn or vitamin D3, as well as by infectious bronchitis or Newcastle disease IB. However, among the main causes of eggshell quality issues is heat stress.

In hot temperatures, increased respiration rates can cause an increase in CO₂ loss. The reduction of the pool of bicarbonate ions can result in respiratory alkalosis and an increase in blood pH[xvi]. A reduction in bicarbonate ions in the shell gland reduces the formation of CaCO₃ and decreases shell quality.

Under heat stress, birds will also tend to decrease their feed intake during the day to reduce diet-induced thermogenesis. Calcium intake is therefore also reduced, and shell quality decreases as a consequence.

3 solutions for eggshell quality in older layers

Midnight feeding in hot climates

At midnight, when temperatures are typically cooler, the addition of one to two hours of light can help the birds increase feed consumption[xvii]. Midnight feeding can also have the benefit of providing a dietary source of Ca to support eggshell formation during the night and reduce reliance on bone reserves[xviii].

Nutrition supplements

Along with Calcium, some micro-minerals can also influence eggshell quality. Zinc, Manganese and Copper act as cofactors of enzymes involved in the mineralization process during eggshell formation. Although European Union legislation restricts the use of high levels of these minerals, several studies in layers indicate increased egg shell resistance by increasing the dietary concentrations of microminerals. Using organic forms of Zinc, Manganese and Copper appears to be an alternative way to increase the absorption of these minerals, as organic forms appear to be more digestible than inorganic forms. Considering the high cost of organic minerals, a mix of organic and inorganic forms of critical minerals could be a better option.

Liquid Ca supplements

If a hen is fed a diet containing only a small-particle Ca sources, such as finely ground limestone, the intestine will be deprived of a source of Ca during the night, when demand for Ca is highest. At that point, the hen will be entirely reliant on bone Ca to support eggshell formation. A combination of Ca supplementation through water additives can be a good alternative as readily available Ca to the hen to support high Ca requirements during the late afternoon and through the night. Liquid Ca additives also offer further precise and user-friendly    application.

Stimuvital IP: a liquid solution from EW Nutrition

Stimuvital IP (formerly Shellimprover) is a liquid nutritional additive for laying hens, supporting the quality of eggshells and bone health. It contains a cocktail of Ca and vitamins whose benefits in laying birds are well proven through field studies, existing literature, and years of market experience.

Benefits proven in Australia field trial

22,500 layer birds were split into two equal-size groups, one of which (11250 birds) was supplemented with Stimuvital IP for 3 days every two weeks, starting from age 53^rd to 63^rd week. Improvements in eggshell thickness and strength could be noticed after the application of Shellimprover. Egg weight was consistent in Stimuvital IP -supplemented birds.3 days every fortnight by using the Easy@ system. In total, the 11250 birds received (2 (feed lines) x 3 (times per days) x 265ml x 3 (days) x 6 (week 53, 55, 57, 59, 61, 63) 28620mll of Stimuvital IP.

Benefits proven in China field trial

The field trial was carried out on a commercial layer farm. A control group and Stimuvital IP (Shellimprover) group had 50,000 birds each. Stimuvital IP was supplemented for 3 days every two weeks, starting from age 57^th to 62^nd week. The Stimuvital IP supplementation improved eggshell quality, including eggshell thickness, laying rate, and number of saleable eggs during the trial period.

Optimizing quantity, quality, and overall profitability for layer producers

Ca concentration in the blood is controlled by many interacting feedback loops that involve Ca, phosphate, PTH, vitamin D₃, and calcitonin. Supplementation of Vitamin D₃ can help maintain skeletal and shell quality in high-producing laying hens[xxiv].

Stimuvital IP offers an essential cocktail that caters to the additional requirements of Ca and vitamins in older laying birds. It thus supports Ca metabolism and eggshell quality. And, in the end, better eggshell quality reduces broken egg percentage and optimizes the number of salable eggs and profitability for layer producers.

Notes

[i] Pelicia et al., 2009; Bello and Korver, 2019

[ii] Nys et al., 2004

[iii] Orban and Roland Sr, 1990

[iv] Bello and Korver, 2019

[v] Driggers and Comar, 1949

[vi] Roland Sr et al., 1975

[vii] Wistedt et al., 2019

[viii] Miles et al., 1983

[ix] Wen et al., 2019

[x] Silva, 2017; Akbari Moghaddam Kakhki et al., 2019

[xi] Beuving and Vonder, 1981

[xii] Roberts, 2004

[xiii] Hincke et al., 2012

[xiv] Samiullah et al., 2016; Hunniford et al., 2017

[xv] Hincke et al., 2012

[xvi] Franco-Jimenez et al., 2007

[xvii] van Staaveren et al., 2018

[xviii] Harms et al., 1996

[xix] Chowdhury, 1990

[xx] Leach and Gross, 1983

[xxi] Zhang et al., 2017

[xxii] Atteh and Leeson, 1983

[xxiii] Atteh and Leeson, 1985

[xxiv] Silva, 2017; Akbari Moghaddam Kakhki et al., 2019

Full references are available upon request.

Why moisture management requires both surfactants and organic acids

Moisture management starts with monitoring certain indicators. The moisture content measures the total amount of water contained in a substance, usually expressed as a percentage of the total weight. Feed manufacturers track the moisture contents of raw materials, mash feed, and pellets during all processing stages  to optimize quality, yields, and profitability.

For the purpose of preventing mold growth, however, another indicator is even more critical: water activity (a_w) is technically defined as the ratio of partial vapor pressure of water in a substance to the partial vapor pressure of pure water under the same temperature and pressure conditions. What this captures is the energy state of water in a substance, i.e. its potential for (bio)chemical activity, including the growth of bacteria, yeasts, and molds. Simply put, microorganisms will usually not grow below a certain water activity level, and the higher the water activity, the higher the chance of microbial growth (Roos, 2003).

Minimum water activity (a_w) for growth and toxin production of toxigenic fungi affecting grains

Adapted from Magan, Aldred, and Sanchis (2004)

Can we condition feed with pure water?

Why does this matter? The intense friction during grinding and mixing results in heat; subsequently, moisture from the mash feed is lost in the form of vapor. These losses need to be mitigated, when the feed is too dry, the milling equipment cannot function optimally and the pellet quality deteriorates. However, simply adding water does not work well: Pure water does not readily bind to the feed; it effectively “sits on top” of the feed surface, increases the feed’s water activity and thus becomes a perfect substrate for microbial growth. Plus, pure water steam largely evaporates again when the feed is cooled.

Surfactants

Hence, at the conditioning phase, it is critical to add surfactants to the hydrating solution. Surfactants change the way water behaves: by reducing the surface tension of water, they enable the feed particles to absorb the water and ensure that it is evenly distributed throughout the feed. There are numerous beneficial effects as improved moisture retention

• facilitates the starch gelatinization during conditioning (important for pellet digestibility and durability),
• minimizes feed shrinkage at the cooling stage,
• reduces friction and hence the energy required for the pellet die (improving milling efficiency), and
• curbs microbial growth by reducing water activity.

While surfactants contribute to mold control, feed manufacturers also require the help of organic acids to optimize the moisture content in feed while reliably preventing mold (re)contamination hazards along the distribution chain.

Organic acids

Let us consider how the most effective one, propionic acid, works: In its non-dissociated state, propionic acid has all its hydrogen ions attached to the molecule. Once it enters a mold cell, the propionic acid dissociates, meaning the hydrogen ions separate from the molecule. They reduce the intracellular pH in the mold cell and inhibit its metabolic pathways, ultimately leading to cell death (Smith et al., 1983).

Common feed ingredients such as soybean meal, maize, wheat, barley, and dehulled oats are often stored for several months. Given variable and likely challenging temperature, oxygen, and moisture conditions, their water activity levels can easily escalate (Mannaa and  Kim, 2017) – rendering the long-lasting anti-fungal activity of targeted organic acid preconditioning even more important.

SURF•ACE: Improve mill performance and pellet quality

A synergistic blend of organic acids and surfactants can achieve the objective of adding moisture without risking either the subsequent loss of moisture during cooling or the development of mold. This is the working principle behind SURF•ACE^TM feed mill processing aid, carefully formulated to best achieve the dual objective of higher feed quality and higher production efficiency. This objective is achieved in concordance with optimal resource use and lower energy requirements, thus also contributing to the feed industry’s environmental commitments.

Improved press yield

The effect of adding SURF•ACE to diets with increasing levels of fat were evaluated at more than 40 feed mills, with production capacities ranging from 5 to 20 tons per hour, under identical electricity consumption conditions. The results show that the addition of SURF•ACE to the preconditioning solution increases press throughout (t/h), relative to pure water preconditioning, by between 9 and 23 %, depending on how much preconditioning solution is applied and the level of fat in the diet:

Addition of SURF•ACE increases press throughput

*Including large volumes of hydrating solution in high-fat diets might adversely affect the durability values of the feed

What is the role of fat in this scenario? Dietary fat acts as a lubricant between the feed and the pellet die, reducing the pressure within the die. The higher the percentage of fat included in the mixer, the lower the energy required to process the mash (Pope, Brake, und Fahrenholz, 2018). The surfactants contained in SURF•ACE have an emulsifying effect; they help bind water to the fat element of the feed. The emulsion of water and fat “behaves” like fat, improving the lubrication of press and generating a higher throughput for the same electricity consumption.

Higher pellet quality

Importantly, adding SURF•ACE does not negatively affect pellet durability, a common issue in high-fat diets (Moritz et al., 2003). On the contrary, it enhances pellet durability as more crystal starch becomes gelatinized. This translates into improved results for Holmen pellet durability testing:

Addition of SURF•ACE improves pellet durability

Pellets need to withstand significant pneumatic handling, for example, during bagging and transport, and in the feed lines. The Holmen durability tester simulates this handling, and calculates the percentage of fine generated, expressed as a pellet durability index (PDI). Across six different poultry compound feed types, SURF•ACE improves pellet quality and thus the PDI. Fewer fines equate to less reprocessing for feed manufacturers and higher palatability for animals.

The next level in compound feed production

Achieving optimal moisture levels in compound feed is a complex balancing act involving technical constraints, raw material variability, microbial challenges, and the price pressures of competitive feed markets. Feed mills generally operate within a particular comfort zone, a throughput and quality level at which they minimize production problems. Thanks to its dual surfactant and preservative effects, SURF•ACE feed mill processing aid expands the comfort zone in two dimensions: From an economic point of view, the improved lubrication gives mills the choice of either pushing their performance levels closer to their equipment’s potential capacity or achieving the same results at lower electricity use. From a feed quality angle, effective mold prevention and improved pellet quality allow for safer, more palatable feed – and from there we come full circle, to safe, nutritious food for all of us.

References

Magan, Naresh, David Aldred, and Vicente Sanchis. “The Role of Spoilage Fungi in Seed Deterioration.” Essay. In Fungal Biotechnology in Agricultural, Food, and Environmental Applications, edited by Dilip K. Arora, 311–23. New York: Marcel Dekker, 2004.

Mannaa, Mohamed, and Ki Deok Kim. “Influence of Temperature and Water Activity on Deleterious Fungi and Mycotoxin Production during Grain Storage.” Mycobiology 45, no. 4 (2017): 240–54. https://doi.org/10.5941/myco.2017.45.4.240.

Moritz, J. S., K. J. Wilson, K. R. Cramer, R. S. Beyer, L. J. McKinney, W. B. Cavalcanti, and X. Mo. “Effect of Formulation Density, Moisture, and Surfactant on Feed Manufacturing, Pellet Quality, and Broiler Performance.” Journal of Applied Poultry Research 11, no. 2 (2002): 155–63. https://doi.org/10.1093/japr/11.2.155.

Moritz, J. S., K. R. Cramer, K. J. Wilson, and R. S. Beyer. “Feed Manufacture and Feeding of Rations with Graded Levels of Added Moisture Formulated to Different Energy Densities.” Journal of Applied Poultry Research 12, no. 3 (October 1, 2003): 371–81. https://doi.org/10.1093/japr/12.3.371.

Pope, J. T., J. Brake, and A. C. Fahrenholz. “Post-Pellet Liquid Application Fat Disproportionately Coats Fines and Affects Mixed-Sex Broiler Live Performance from 16 to 42 d of Age.” Journal of Applied Poultry Research 27, no. 1 (March 1, 2018): 124–31. https://doi.org/10.3382/japr/pfx054.

Roos, Y. H. “WATER ACTIVITY | Effect on Food Stability.” Essay. In Encyclopedia of Food Sciences and Nutrition Second Edition, edited by Luiz Trugo and Paul M. Finglas, 6094–6101. Cambridge, MA: Academic Press, 2003.

Smith, Philip A., Talmadge S. Nelson, Linda K. Kirby, Zelpha B. Johnson, and Joseph N. Beasley. “Influence of Temperature, Moisture, and Propionic Acid on Mold Growth and Toxin Production on Corn.” Poultry Science 62, no. 3 (1983): 419–23. https://doi.org/10.3382/ps.0620419.

by  Merideth Parke, Regional Technical Manager, EW Nutrition

To contain and reverse antimicrobial resistance, consumers and government regulators expect changes in pork production with the clear goal to reduce antibiotic use. For healthy, profitable pig production with simultaneous antibiotic reduction, a holistic strategy is required: refocusing human attitudes and habits, optimal pig health and welfare, and applying potential antibiotic alternatives.

Pig producers need to manage pathogenic pressure while reducing antibiotics

Intensive pig production has stress points associated with essential husbandry procedures such as weaning, health interventions, and dietary modifications. Stress is widely accepted to have a negative impact on immune system effectiveness, enhancing opportunities for pathogenic bacteria to invade at a local or systemic level. The gastrointestinal and respiratory systems are highly susceptible to developing disease as a result of these combined factors. Interventions such as antibiotics are commonly implemented to reduce the impact of pathogens and manage pig health. Processes that minimize the number of pathogens in the environment are the foundation for a successful antibiotic reduction plan. The challenge is to smartly combine strategies to keep the gastrointestinal and respiratory tract intact and robust.

Phytomolecules, the specific active defense compounds found in plants, have been identified as capable of enhancing pig health through antimicrobial (Cimanga et al., 2002, Franz et al., 2010), antioxidative (Katalinic et al., 2006, Damjanovic-Vratnica et al., 2007, Lee et al., 2011), digestion-stimulating and immune-supportive functions. As many thousands of phytomolecules exist,  laboratory research has focused on identifying those with the capability of microbial management, facilitating the end goal of reducing the reliance on antibiotics for pig health and welfare and the production of safe pork (Zhai et al., 2018).

Which roles can phytomolecules play in reducing antibiotics?

The gastrointestinal tract benefits from applying phytomolecules such as capsaicin, carvacrol, and cinnamaldehyde, as they:

• support a balanced and stable biome,
• prevent dysbiosis, maintain tight junction integrity (Liu et al., 2018),
• increase secretion of digestive enzymes, and
• enhance gut contractility (Zhai et al., 2018).

Pigs most susceptible and in need of phytomolecule gastrointestinal supportive actions are piglets at weaning and pigs of all ages undergoing stress, pathogen challenges, and/or dietary changes.

Porcine respiratory disease is a complex multifactorial disorder. It frequently requires antibiotics to manage infection pressure and clinical disease to maintain pig health, welfare, and production performance. Causal pathogens may be transmitted by direct contact between pigs in saliva (Murase et al., 2018) or bioaerosols (LeBel et al., 2019), via the nasal or oral cavities (inhalation directly into the airways and lungs), or via an unhealthy gut. Phytomolecules such as carvacrol and cinnamaldehyde have antimicrobial properties. Hence, they may help contain respiratory pathogens in their natural habitat (the upper respiratory tract) or during transit through the oronasal cavity and gastrointestinal tract (Swildens et al., 2004, Lee et al., 2001).

In addition to supporting the gastrointestinal and respiratory systems, phytomolecules such as menthol and 1,8-cineole have been shown to enhance the physical and adaptive immune systems in multiple species (Brown et al., 2017, Barbour et al., 2013). When applied via drinking water, adherence to the oronasal mucosa facilitates the inhalation of the active phytomolecule compounds into the respiratory tract. There, they act as mucolytics, muscle relaxants, and enhancers of the mucociliary clearance mechanism (Başer and Buchbauer, 2020). Phytomolecules have also been documented to positively influence the adaptive immune system, promoting both humoral and cell-mediated immune responses (Awaad et al., 2010, Gopi et al., 2014, Serafino et al., 2008).

How phytomolecules feature in the holistic approach to antibiotic reduction

Antibiotic reduction programs positively enact social responsibility by reducing the risk to farmworkers of exposure to antimicrobial-resistant bacteria. They also help maintain or increase efficiency in safe pork production – pork with minimal risk of antibiotic residues.

Implementation of a successful health program with reduced antibiotic use will require:

• application of strict internal and external biosecurity processes;
• evaluation and monitoring of AMR bacteria;
• partnerships with specialist nutritionists to target a lifetime healthy gut biome; and
• phytomolecule-assisted health management (Figure 1).

A combination of in vitro and in vivo studies provides evidence that specific phytomolecules can support both enteric and respiratory systems through biome stabilisation and pathogen management (Bajabai et al., 2020). Antimicrobial activity of thymol, carvacrol, and cinnamaldehyde has been reported against respiratory pathogens including S. suis, A. pleuropneumoniae, and H. parasuis (LeBel et al., 2019); multi-drug resistant and ESBL bacteria (Bozin et al., 2006); enteric pathogens including E. coli, Salmonella enteritidis, Salmonella cholerasuis, and Salmonella typhimurium (Penalver et al., 2005); Clostridium spp., E. coli spp., Brachyspira hyodysenteriae (Vande Maelle et al., 2015); and Lawsonia intracellularis (Draskovic et al., 2018). These results have shown phytomolecules to be effective antimicrobial alternatives for incorporation into holistic pig health programs.

Additionally, the inclusion of phytomolecules into pig production systems also enhances production performance by reducing the negative impact of stress on the pig and increasing the positive effects on gut health and nutrient utilization (Franz et al., 2010). Phytomolecules that directly impact digestive actions include capsaicin, which optimizes the production of digestive enzymes and increases serotonin for gut contraction maintenance and improved digesta mixing (Zhai et al., 2018). Cineol’s antioxidative activities provide support during times of stress (Cimanga et al., 2002).

Phytomolecules are key to reducing antibiotics in pig production

The pig industry searches for alternatives to therapeutic, prophylactic, and growth-promoting antibiotic applications to keep available antibiotics effective for longer – and to address the social responsibility of mitigating AMR. This search for ways to produce safe pork has made it clear that only a combination of management and antibiotic alternatives can achieve these aligned goals.

Biosecurity, hygiene, stress reduction, and husbandry and nutritional advances form the foundation for the strategic application of specific phytomolecules (Zeng et al. 2016). Supporting pig production and health, this complete holistic solution (EIP-AGRI) moves the pig industry into a future where antibiotic reduction or removal, with equivalent or increased production of safe pork, becomes a reality.

References

Awaard M, Abdel-Alim G, Sayed K, Kawkab, Ahmed1 A, Nada A , Metwalli A, Alkhalaf A. “Immunostimulant effects of essential oils of peppermint and eucalyptus in chickens”. Pakistan Veterinary Journal (2010). 2:61-66. http://www.pvj.com.pk/

Bajagai YS, Alsemgeest J, Moore RJ, Van TTH, Stanley D. “Phytogenic products, used as alternatives to antibiotic growth promoters, modify the intestinal microbiota derived from a range of production systems: an in vitro model”. Applied Microbiology and Biotechnology (2020). 104:10631-10640. https://doi.org/10.1007/s00253-020-10998-x

Barbour EK, Shaib H, Azhar E, Kumosani T, Iyer A, Harakey S, Damanhouri G, Chaudary A, Bragg RR. “Modulation by essential oil of vaccine response and production improvement in chicken challenged with velogenic Newcastle disease virus”. Journal of Applied Microbiology (2013). 115, 1278-1286. https://doi:10.1111/jam.12334

Biljana Damjanovic-Vratnica, Tatjana Dakov, Danijela Sukovic, Jovanka Damjanovic. “Antimicrobial effect of essential oil isolated from Eucalyptus globulus Labill” (2011). Czech Journal of Food Science 27(3):277-284. https://www.agriculturejournals.cz/publicFiles/39925.pdf

Bozin B, Mimica-Dukic N, Smin N, Anackov G. “Characterization of the volatile composition of essential oils of some Lamiaceae spices and the antimicrobial and antioxidant activities of the entire oils” Journal of Agriculture and Food Chemicals (2006). 54:1822-1828 https://pubs.acs.org/doi/10.1021/jf051922u

Brown SK, Garver WS, Orlando RA. “1,8-cineole: An Underappreciated Anti-inflammatory Therpeutic” Journal of Biomolecular Research &Therapeutics (2017). 6:1 1-6  https://doi: 10.4172/2167-7956.1000154

Cimanga K., Kambu K., Tona L., Apers S., De Bruyne T., Hermans N., Totte J., Pieters L., Vlietinck A.J. “Correlation between chemical composition and antibacterial activity of essential oils of some aromatic medicinal plants growing in the Democratic Republic of Congo”. Journal of Ethnopharmacology (2002) 79: 213–220. https://doi.org/10.1016/s0378-8741(01)00384-1

Draskovic V, Bosnjak-Neumuller J, Vasiljevic M, Petrujkic B, Aleksic N, Kukolj V, Stanimirovic Z. “Influence of phytogenic feed additive on Lawsonia intracellularis infection in pigs” Preventative Veterinary Medicine (2018). 151: 46-51 https://doi.org/10.1016/j.prevetmed.2018.01.002

European Innovation Partnership Agricultural Productivity and Sustainability (EIP-AGRI). https://ec.europa.eu/eip/agriculture/en/european-innovation-partnership-agricultural

Franz C., Baser KHC, Windisch W. “Essential oils and aromatic plants in animal feeding-a European perspective. A review Flavour”. Flavour and Fragrance Journal (2010) 25:327-40. https://doi.org/10.1002/ffj.1967

Gopi M, Karthik K, Manjunathachar H, Tamilmahan P, Kesavan M, Dashprakash M, Balaraju B, Purushothaman M. “Essential oils as a feed additive in poultry nutrition”. Advances in  Animal and Veterinary Sciences (2014) 1:17.  https://doi.10.14737/journal.aavs/2014.2.1.1.7

Başer, Kemal Hüsnü Can, and Gerhard Buchbauer. Handbook of Essential Oils Science, Technology, and Applications. Boca Raton: CRC Press, 2020.

Hengziao Zhai, Hong Liu, Shikui Wang, Jinlong Wu, Anna-Maria Kluenter. “Potential of essential oils for poultry and pigs.” Animal Nutrition 4 (2018): 179-186.  https://doi.org/10.1016/j.aninu.2018.01.005

Katalinic V., Milos M., Kulisic T., Jukic M. “Screening of 70 medicinal plant extracts for antioxidant capacity and total phenols”. Food Chemistry (2006) 94(4):550-557.  https://doi.org/10.1016/j.foodchem.2004.12.004

LeBel G., Vaillancourt K., Bercier P., Grenier D. “Antibacterial activity against porcine respiratory bacterial pathogens and in vitro biocompatibility of essential oils”. Archives of Microbiology (2019) 201:833-840; https://doi.org/10.1007/s00203-019-01655-7

Lee KG, Shibamoto T. “Antioxidant activities of volatile components isolated from Eucalyptus species”. Journal of the Science of Food and Agriculture (2001). 81:1573-1597. https://doi.org/10.1002/jsfa.980

Liu SD, Song MH, Yun W, Lee JH, Lee CH, Kwak WG Han NS, Kim HB, Cho JH. “Effects of oral administration of different dosages of carvacrol essential oils on intestinal barrier function in broilers” Journal of Animal Physiology and Animal Production (2018) https://doi.org/10.1111/jpn.12944

Murase K, Watanabe T, Arai S, Kim H, Tohya M, Ishida-Kuroki K, Vo T, Nguyen T, Nakagawa I, Osawa R, Nguyen N, Sekizaki T. “Characterization of pig saliva as the major natural habitat of Streptococcus suis by analyzing oral, fecal, vaginal, and environmental microbiota”. PLoS ONE (2019). 14(4). https://doi.org/10.1371/journal.pone.0215983

Nethmap MARAN report 2018. https://www.wur.nl/upload_mm/7/b/0/5e568649-c674-420e-a2ca-acc8ca56f016_Maran%202018.pdf

Penalver P, Huerta B, Borge C, Astorga R, Romero R, Perea A. “Antimicrobial activity of 5 essential oils against origin strains of the Enterobacteriaceae family”. Acta Pathologica Microbiologica, et Immunologica Scandinavica (2005) 113:1-6. AromaticScience, LLC Antimicrobial activity of five essential oils against origin strains of the Enterobacteriaceae family.

Serafino A, Vallebona PS, Adnreola F, Zonfrillo M, Mercuri L, Federici M, Rasi G, Garaci E, Pierimarchi P. “Stimulatory effect of Eucalyptus essential oil on innate cell-mediated immune response” BioMed Central (2008). 9:17 https//:doi:10.1186/1471-2172-9-17

Swildens B, Stockhofe-Zurwieden N, van der Meulen J, Wisselink HJ, Nielen M. “Intestinal translocation of Streptococcus suis type 2 EF+ in pigs”. Veterinary Microbiology (2004) 103:29-33. https://doi: 10.1016/j.vetmic.2004.06.010

Vande Maele L, Heyndrickx M, Maes D, De Pauw N, Mahu M, Verlinden M, Haesbrouck F, Martel A, Pasmans F, Boyen F. “In vitro susceptibility of Brachyspira hyodysenteriae to organic acids and essential oil components”. Journal of Veterinary Medical Science (2016). 78(2):325-328.  https://doi.org/10/1292/jvms.15-0341

Zeng Z, Zhang S, Wang H, Piao X. “Essential oil and aromatic plants as feed additives in non-ruminant nutrition: a review”. Journal of Animal Science and Biotechnology (2015) 6:7. https://doi.org?10/1186/s40104-015-004-5

How to achieve feed hygiene

Feed hygiene requires the control of microorganisms throughout the feed production chain. However, producers or retailers can rarely certify or verify feedstuffs’ safety due to the wide range of potential microbial contamination agents and hazards encountered in different feed environments (den Hartog, 2003). The relationship between feed and microorganisms varies, depending on the conditions: feed can transport pathogenic microorganisms and thus directly transmit disease; likewise, microorganisms can also be responsible for feed spoilage and thereby indirectly cause issues (Baer, Miller, and Dilger, 2013).

Since its foundation, the World Organization for Animal Health (OIE) has established standards, guidelines, and recommendations for toxin risk management, including for microorganisms that are transmissible via feed. Recurring outbreaks of Salmonella, Escherichia coli, and other familiar Enterobacteriaceae are a key concern for animal health professionals and the feed industry (Elsayed et al., 2021). However, as factors ranging from climate change to genetic mutations come into play, feed producers are working with moving targets; some of the most significant issues they might face tomorrow are unknown today. There are no easy solutions to these multifactorial problems – but in any case, corrective measures need to include quality control and quality assurance for assessing and managing the pathogenic and microbial risk situation.

To improve animal productivity sustainably, producers regularly experiment with modifying production techniques, innovating feed formulations, but also exploring new ingredients. The inclusion of new ingredients such as animal proteins, oils, and fermented products, among others, heightens the need for strict feed quality monitoring (Truelock et al., 2020). New ingredients come with causative agents of feedborne illnesses, some of which might be unknown (Goodarzi Boroojeni et al., 2016). Therefore, feed and animal producers need to consider how feed changes impact feed safety and include these hazards in their planning and risk assessments.

Better feed hygiene is crucial

For any animal production, feed processing constitutes the most crucial part of feed hygiene management, as it covers all treatments of the feed before ingestion. It is referred to as “hydrothermal processing” due to the use of heat that is required to kill most of the pathogens in raw materials, feedstuffs, and compound feed (Jones, 2011). However, whether or not hydrothermal processing will effectively eliminate a given pathogen depends on its heat resistance. Moreover, factors such as the type of feed components involved and water activity levels also need to be considered to reduce microbial pressure (Doyle and Mazzotta, 2000).

The new generation of feed milling equipment – besides elevating feed costs – can also improve feed quality (Truelock et al., 2020). These technologies tend to enhance feed stability and hygiene by modifying the physicochemical properties of the ingredients. This improves the absorption of nutrients, thereby enabling a higher feed intake efficiency with positive results for animal performance (Abdollahi, Svihus, and Ravindran, 2013). However, while increasing processing time at a given temperature can lead to a better decontamination process, it can also negatively affect some nutrients’ dynamics. This includes enzymes, proteins, minerals, vitamins, fiber and starch, and especially non-starch polysaccharides (Goodarzi Boroojeni et al., 2014).

Organic acids as a solution of feed hygiene risk management

Hence, while significant progress in feed science and feed production technology has already been made, researchers and the industry are still searching for alternative approaches to supporting feed hygiene (Goodarzi Boroojeni et al., 2016). Organic acids are a central research field as they offer promising antimicrobial properties. In combination with feed mill techniques, they already play an essential role in feed preservation (Brul et al., 2002). Despite their efficacy in inhibiting microbial growth, weak organic acids are safe to handle (especially when they are buffered) compared to inorganic acids.

In addition to their preservative effect in feed, it has been shown that organic acids can support gut health. They are not just antimicrobial agents but also acidifiers that display their impact in the stomachs of monogastric animals (Tugnoli et al., 2020).

A combined solution for microbial contamination challenges

To support the feed industry and animal production in light of feed safety challenges in AGP-free production, EW Nutrition focuses research efforts on maximizing the beneficial effect of organic acids. The ACIDOMIX range of products supports the stabilization of the gastrointestinal microflora, inhibiting pathogenic bacterial growth in feed and water. Acidomix is an efficient acidifier specially formulated to have strong antimicrobial effects applicable in feed hygiene programs. Various powder and liquid solutions offer a wide range of benefits:

• Strong antimicrobial effect, supporting the prevention of bacterial infections
• Reducing the incidence of dysbiosis
• Acidifying the feed and digestive tract
• Supporting the improvement of production performance
• Preventing feed re-contamination
• Flexible application

Feedstuffs and compound feed are at risk of contamination and re-contamination throughout the feed production chain: processing, transportation, delivery, storage, and on-farm. Thus, a holistic and integrated approach that includes optimized feed mill processing and customized organic acids is required to improve the feed’s hygiene status. The positive effects are clear: feed producers benefit economically, animal producers reap the effects of improved animal health and performance, and people get to enjoy producing and consuming safe and nutritious food.

References

Abdollahi, M R, B Svihus, and V Ravindran. 2013. “Pelleting of Broiler Diets: An Overview with Emphasis on Pellet Quality and Nutritional Value.” Animal Feed Science and Technology 179 (1–4): 1–23. https://doi.org/10.1016/j.anifeedsci.2012.10.011.

Baer, Arica A, Michael J Miller, and Anna C Dilger. 2013. “Pathogens of Interest to the Pork Industry: A Review of Research on Interventions to Assure Food Safety.” Comprehensive Reviews in Food Science and Food Safety 12 (2): 183–217. https://doi.org/10.1111/1541-4337.12001.

Brul, Stanley, Peter Coote, Suus Oomes, Femke Mensonides, Klaas Hellingwerf, and Frans Klis. 2002. “Physiological Actions of Preservative Agents: Prospective of Use of Modern Microbiological Techniques in Assessing Microbial Behaviour in Food Preservation.” International Journal of Food Microbiology 79 (1–2): 55–64. https://doi.org/10.1016/s0168-1605(02)00179-4.

Doyle, M Ellin, and Alejandro S Mazzotta. 2000. “Review of Studies on the Thermal Resistance of Salmonellae.” Journal of Food Protection 63 (6): 779–95. https://doi.org/10.4315/0362-028x-63.6.779.

Elsayed, Mohamed Sabry Abd Elraheam, Awad A Shehata, Ahmed Mohamed Ammar, Tamer S Allam, and Reda Tarabees. 2021. “The Beneficial Effects of a Multistrain Potential Probiotic, Formic, and Lactic Acids with Different Vaccination Regimens on Broiler Chickens Challenged with Multidrug-Resistant Escherichia Coli and Salmonella.” Saudi Journal of Biological Sciences. https://doi.org/10.1016/j.sjbs.2021.02.017.

Goodarzi Boroojeni, Farshad, Birger Svihus, Heinrich Graf von Reichenbach, and Jürgen Zentek. 2016. “The Effects of Hydrothermal Processing on Feed Hygiene, Nutrient Availability, Intestinal Microbiota and Morphology in Poultry—A Review.” Animal Feed Science and Technology 220: 187–215. https://doi.org/10.1016/j.anifeedsci.2016.07.010.

Den Hartog, Johan den. 2003. “Feed for Food: HACCP in the Animal Feed Industry.” Food Control 14 (2): 95–99. https://doi.org/10.1016/S0956-7135(02)00111-1.

Jones, Frank T. 2011. “A Review of Practical Salmonella Control Measures in Animal Feed.” Journal of Applied Poultry Research 20 (1): 102–13. https://doi.org/10.3382/japr.2010-00281.

Truelock, Courtney N, Mike D Tokach, Charles R Stark, and Chad B Paulk. 2020. “Pelleting and Starch Characteristics of Diets Containing Different Corn Varieties.” Translational Animal Science 4 (4): txaa189. https://doi.org/10.1093/tas/txaa189.

Tugnoli, Benedetta, Giulia Giovagnoni, Andrea Piva, and Ester Grilli. 2020. “From Acidifiers to Intestinal Health Enhancers: How Organic Acids Can Improve Growth Efficiency of Pigs.” Animals 10 (1): 134. https://doi.org/10.3390/ani10010134.

Goodarzi Boroojeni, F., W. Vahjen, A. Mader, F. Knorr, I. Ruhnke, I. Röhe, A. Hafeez, C. Villodre, K. Männer, and J. Zentek. “The Effects of Different Thermal Treatments and Organic Acid Levels in Feed on Microbial Composition and Activity in Gastrointestinal Tract of Broilers.” Poultry Science 93, no. 6 (June 1, 2014): 1440–52. https://doi.org/10.3382/ps.2013-03763.

In contrast to humans, piglets do not receive any maternal immunoglobulins via the placenta. It is therefore of vital importance for these young animals to receive maternal antibodies via the colostrum as soon as possible after birth. Otherwise, they are more vulnerable to illnesses in their early stages of life.

In this article, we look in-depth at how the immune system works and which role antibodies play in it.  We then consider why immunoglobulins from the egg (IgY) might potentially be a powerful tool for supporting young animals immunologically, allowing producers to maintain young animals’ health and to promote their performance.

How the immune system defends the body: three barriers

The immune system aims to prevent pathogens such as viruses, bacteria, and fungi from entering the body or to eliminate them when they have already entered. Furthermore, it seeks to prepare the body for quicker reactions, in case of subsequent infections, by building an immunological memory. Generally, in case of an attack by pathogens, there are three barriers against the “enemy” (Figure 1).

Figure 1: The three barriers of the immune response

First barrier: the immediate, physical defense upon contact with pathogens

The animal body has several anatomical features that prevent pathogens from entering in the first place, such as cilia and mucus. Skin, intestines and nose lining are colonized by a community of beneficial micro-organisms that form a physical barrier against pathogens. Other barriers include the urinary system, the acid pH of the stomach, as well as tears and saliva, which contain antibacterial lysozymes.

Second barrier: the unspecific, native defense that does most of the work

If the mechanical mechanisms of defense were not successful, the unspecific, innate immune defense enters into play (Murphy and Weaver, 2018, 47ff.). At this stage, the body needs to differentiate between “known” and “alien” agents, and between “potentially harmful” and “harmless” ones.

To identify alien, potentially harmful agents, the unspecific defense looks for so-called PAMPs (pathogen associated molecular patterns). These are general characteristics often displayed by pathogens, such as lipopolysaccharides in the bacterial membrane or double-stranded RNA in viruses. Everything that shows PAMPs is heavily targeted.

The unspecific defense can be further divided into the humoral and the cellular defense. The humoral defense consists of substances dissolved in the body fluids, such as enzymes, reactive oxygen compounds, signal molecules and a whole cascade of proteins. Some of these substances kill pathogens directly; others “mark” the pathogens and “call for” the help of leucocytes.

The cellular defense consists of different leucocytes, also known as white blood cells (because they do not contain any red hemoglobin). The main task of leucocytes is the defense of the body against pathogens, hence many leucocytes are capable of phagocytosis (the ingestion of other cells). To prevent phagocytes from accidentally ingesting the body’s own cells, these own cells are marked with the so-called major histocompatibility complex (MHC). This acts as a red flag, saying “I belong to the body!”.

The cellular defense consists of:

• Neutrophil granulocytes (60-70% of the leucocytes), which mainly act against bacteria
• Eosinophil and basophil granulocytes (1.5% of the leucocytes), which mainly act against parasites
• Natural killer cells, which mainly act against viruses
• Monocytes (3-8% of the leucocytes; they differentiate into macrophages and dendritic cells)

Figure 1: The three barriers of the immune response

The monocytes, as well as their macrophage and dendritic cell “offspring”, are the bridge to the next step, the specific defense. When these phagocytes digest pathogens, minuscule protein structures (antigens) of the pathogens remain. These antigens are unique to each pathogen. During a process called antigen presentation, the antigens are tied to the cell’s MHC and transported to the cell surface. This triggers the production of specific antibodies, the immune system’s third barrier.

Third barrier: the specific immune defense that creates antibodies and immunological memory

The specific (also called adaptive or acquired) immune response kicks in a few days after contact with specific pathogens and is mostly carried out by lymphocytes called T and B cells (Murphy and Weaver, 2018, 177ff.). They are active at the cellular and the humoral level, respectively.

T cells possess receptors on their surface through which they can recognize the antigens presented to them by phagocytes. What they do subsequently depends on the subtype of the T cell:

• Cytotoxic T cells (CD8+) directly destroy the antigen-phagocyte-combination
• T helper cells (CD4+) attract other cells that can destroy the pathogens (e.g. macrophages) and stimulate B cells to produce antibodies against them

B cells also possess receptors through which they can recognize antigens. Once they spot an antigen (and T helper cells “confirm” that an immune response is required), they divide and mature into so-called plasma cells. Plasma cells, in turn, secrete plenty of antibodies (or immunoglobulins) into the bloodstream and the lymphatic system. Antibodies are protein structures that lock onto and neutralize antigens through different mechanisms.

The chemical reaction between antibodies and antigens is the body’s most powerful immune response through which it can protect itself from pathogens and their toxins. Antibody production continues for several days to remove the antigens, and antibodies usually remain in circulation for a few months.

Moreover, certain T and B cells memorize the first attack of a pathogen and turn into memory cells. The T memory cells CD4+CD8+, for instance, match the antigens from certain past, latent, and particularly persistent viral infections. This immunological memory, created by acquired immunity, can be thought of as a library of antibodies that the body adds to whenever it deals with a new pathogen or receives a vaccine. In case of a subsequent contact with the pathogen, the right antibody “model” already exists and mass production can start up very quickly.

Why young animals’ immune defense is so vulnerable – and what IgY can do about that

Building one’s immunological memory takes time. A lot of new-born animals are in a vulnerable position: they have not had time yet to acquire immunity of their own, but they are also particularly fragile and susceptible to being attacked by commonly occurring pathogens such as corona and rotaviruses, E. coli and clostridia. The toxins that E. coli and clostridia, for instance, release, may cause diarrhea, edema, endotoxic shock, and even death.

To be protected during the first critical days of their lives, new-born animals thus need to receive a foundational stock of antibodies (passive immunity) from their mother. Humans receive maternal immunoglobulins via the placenta. Piglets, because a sow’s placenta is constructed differently, are dependent on receiving them through the colostrum after birth. If this is not the case – due to inadequate quantity or quality of the colostrum – they need to receive immune support in a different way.

Egg-yolk antibodies have been proposed as a powerful tool for supporting young animals during the critical period after birth. These special proteins support the colostrum supply and guarantee that every animal in the herd has some degree of protection. This protection mostly takes place in the gut. The IgY recognize and tie up pathogens and render them ineffective.

Trial: can egg immunoglobulins support piglet immunity?

In 2009, research at the National Veterinary Research Institute in Pulawy, Poland, was conducted to probe this hypothesis. The objective of the trial was to evaluate whether an oral application of egg immunoglobulins would have a quantifiable, positive influence on the immune system of the piglets. Different immunological parameters were measured, including different types of leucocytes.

Trial design

The test consists of 6 litters with 67 piglets in total divided into two groups. The control group (n=32) received the prophylaxis customary on the farm; the trial group (n=35) additionally received a product based on egg powder (EP)[1], applied at the inclusion rate recommended by the producer. Blood samples were taken on days 0 (before application of the product), 7, 14, and 28. They were analyzed with respect to the percentages of different types of lymphocytes.

Trial results

For the group receiving egg powder, the number of leucocytes in peripheral blood was significantly elevated compared to the control group on the 7th day of life (table 1). The amounts of lymphocytes and monocytes – indicators for the specific immunological defense – were also significantly increased on day 7, whereas the total amount of granulocytes – indicator for the innate, unspecific immune defense – remained constant. Hence, already during the first days, the piglets supplied with EP disposed of a higher level of adaptive (specific) immune defense, compared to the animals in the control group. In addition, there was a significant increase in the number of CD4-positive (CD4+) and CD4-CD8-double positive (CD4+CD8+) T cells in the EP group, compared to the control animals, indicating an active stimulation of the immune system.

Except for CD4+CD8+ T cells (which remained elevated in the EP group), on day 14, the differences in cellular immune response were no longer significant. This is most probably the case because by that time the immune system of the control group had activated its own protective response. The EP product therefore supported the young animals precisely when it was necessary, during the critical first days of life.

Table 1: Hematological parameters measured in piglets after prophylactic application of an egg powder based product (EP1)

¹Ig-PRO P (EW Nutrition)

The improvement of immune status, as indicated by the presence of the specific immune cells, was confirmed by the results for the incidence of diarrhea and mortality (table 2). The animals of the control group showed a nearly 1.5 times higher incidence of diarrhea and a 1.6 times higher rate of mortality. Another explanation of these results could be the mode of action of egg immunoglobulins: by neutralizing the pathogens directly in the gut, they prevent them from causing diarrhea in the first place.

Table 2: Incidence of diarrhea and mortality

In conclusion, this trial demonstrates that immunoglobulins from eggs (IgY) effectively support the immune system of piglets during the critical period of the first days of life.
Thanks to the stimulation of the young animals’ specific immune defense and the direct neutralization of pathogens in the gut, the incidence of diarrhea – one of the main causes of losses during the first weeks of life – decreases. Hence, mind the immunity gap: providing piglets with a suitable egg powder based product sets them up for long-term health, growth, and performance.

By I. Heinzl and S. Regragui Mazili

References:

Foley, J. A., and D. E. Otterby. “Availability, Storage, Treatment, Composition, and Feeding Value of Surplus Colostrum: A Review 1, 2.” Journal of Dairy Science 61, no. 8, 1033-1060. doi.org/10.3168/jds.S0022-0302(78)83686-8.
Heinzl, Inge, and Fellipe Barbosa. “Egg Antibody Technology for Nursery Pig Application.” Swineweb.com. June 24, 2019. Accessed July 17, 2019. https://www.swineweb.com/mind-the-immunity-gap-egg-immunoglobulins-bolster-piglets-immune-system/.
Marquardt, Ronald R., L. Z. Jin, Jung-Woo Kim, Lin Fang, Andrew A. Frohlich, and Samuel K. Baidoo. “Passive Protective Effect of Egg-yolk Antibodies against Enterotoxigenic Escherichia Coli K88 Infection in Neonatal and Early-weaned Piglets.” FEMS Immunology and Medical Microbiology 23, no. 4 (1999): 283-288. https://doi.org/10.1111/j.1574-695X.1999.tb01249.x.
Murphy, Kenneth M., and Casey Weaver. 2018. Janeway Immunologie. 9th ed. Translated by Lothar Seidler. Berlin: Springer.
Nascimbeni, Michelina, Eui-Cheol Shin, Luis Chiriboga, David E. Kleiner, and Barbara Rehermann. “Peripheral CD4 CD8 T Cells Are Differentiated Effector Memory Cells with Antiviral Functions.” Blood 104, no. 2 (2004): 478-486. doi:10.1182/blood-2003-12-4395.
Yokoyama, Hideaki, Robert C. Peralta, Roger Diaz, Sadako Sendo, Yutaka Ikemori, and Yoshikatsu Kodama. “Passive Protective Effect of Chicken Egg Yolk Immunoglobulins.” Infection and Immunity 60, no. 3 (March 1992): 998-1007. https://iai.asm.org/content/iai/60/3/998.full.pdf.

The most important parameters for a pig producer are the number of healthy pigs weaned/sow/year and their weaning weight. Due to improved genetics, it is possible today to find production systems that deliver more than 30 pigs weaned/sow/year. Strategies to increase sow productivity need to take into account the management, feeding, and health of both the piglets and the sows.

Pigs’ start in life – limited energy reserves and practically no immune protection

It is generally known that pigs are born physiologically immature. Their energy reserves are limited. They only possess 1-2 % fat, the main part of which is subcutaneous or structural fat protecting organs, joints and skin. Thus, the young pigs depend on the glucose of the glycogen deposits in the liver as main source of energy. This energy supply only meets their requirements for the first few hours.
Besides that, pigs cannot count on maternal antibodies. Unlike in humans, a sow’s placenta is not built to enable the transfer of these protective cells within the womb. At birth, the amount of protective cells in a pig’s intestine, the main site of pathogenic contamination, is therefore virtually zero. As they are born without any immune protection, new-born pigs rely on an early supply of antibodies from the maternal colostrum. During the first 24-36 hours after birth, antibodies are absorbed in the intestine and pass directly to the bloodstream. The intestinal barrier then closes. Importantly, the content of antibodies in the colostrum decreases with every hour after birth.

Prevention – the best way to protect the progeny!

Given this difficult situation in the early stages of life, it is clear that the farrowing unit should be as comfortable as possible for the young animals:

• It should be warm, as low temperatures contribute to hypoglycemia. The search for body heat at the sow additionally increases the risk of crushing, one of the main causes of pig losses. The problem arising here is that sows and the new-born pigs have different temperature requirements. One good solution is a heat lamp, installed specifically for the piglets.
• It should be clean, and pathogenic pressure should be as low as possible. Due to their poor immune status, young pigs are susceptible to diarrhea-causing pathogens like E. coli and Clostridium perfringens during their first days of life. In order to meet hygiene requirements, the first step is a careful cleaning and disinfection of the farrowing unit prior to placing the sows/gilts.

Sows’ manure – the first source of contamination

Cleaning both the farrowing unit and also the sows/gilts before placing them is helpful. Producers, however, have to understand that a sow is continuously shedding pathogens through her feces and that her young come into contact with them. In fact, sow manure is the first source of contamination for new-born pigs.
There are several methods to decrease pathogens within the sow’s gut. Feeding them natural substances such as probiotics or phytomolecules (also known as secondary plant compounds) in order to improve gut health is one possibility: beneficial microbes such as lactobacilli or bifidobacteria compete with pathogens such as E. coli or clostridia for nutrients and prevent their proliferation. Phytomolecules such as carvacrol and cinnamaldehyde, on the other hand, were found to have antimicrobial properties.
Could feeding them egg immunoglobulins be another possibility?

Egg immunoglobulins – the key to reduce pathogenic pressure?

Yokoyama et al. (1992 and 1997) already showed that immunoglobulins from eggs applied to piglets bind to pathogens within their intestinal tract. If they also bind pathogens in the sow’s gut – generating harmless complexes – this could be the key to reduce pathogenic pressure in the farrowing unit.

Trial

Method
To evaluate this possibility a trial was conducted in Japan. Two groups of eight sows were used. The sows of the control group received standard lactation feed. The trial group was also fed standard feed, but additionally received a supplement containing egg powder product (EPP) with immunoglobulins* at a dosage of 5g/sow twice daily during the last ten days before and the first seven days after delivery. The feces of the sows were obtained by rectal stimulation (in order to rule out contamination from the environment) on day 10 before and day 7 after delivery. The amount of colony-forming units (CFU) of total E. coli, E. coli O141 and Clostridium perfringens was determined.

Results
The results are shown in figure 1. At the beginning of the trial, before the application of the EPP, both groups showed nearly the same level of the pathogens evaluated, with a slight disadvantage for the EPP group. After 17 days of using the EPP, the sows of the EPP group showed lower levels of pathogens in their excrements than the sows of the control group. A reduction in the colony-forming units of total Escherichia coli (from 107.12 to 106.3), Escherichia coli O141 (from 106.8 to 105.6) and of Clostridium perfringens (from 105.17 to 104.24) could be seen.

*The product used in this trial was Globimax® Sow, EW Nutrition.

Egg immunoglobulins – a tool to optimize conditions in the farrowing unit

It is important for pig producers to understand how they can combat adverse influences on their animals’ performance. The results of this trial showed that supplementing the standard sows’ diets with the EPP substantially reduced the amount of pathogenic colonies in sow’s manure. Reducing pathogenic pressure in the farrowing unit is central to reducing the incidence of diarrhea and pre-weaning mortality. Giving young pigs the best possible start in life sets them up for delivering the best possible performance – and more healthy and heavy pigs weaned/sow/year means a more profitable farm.

Figure 1: Amounts of total E. coli, O 141 E. coli and Clostridium perfringens in the feces of sows 10 days before delivery (before the first application of EPP) and 7 days after delivery (after the last application of EPP)

By Inge Heinzl and Fellipe Barbosa

References:

Yokoyama, H., Peralta, R. C., Diaz, R., Sendo, S., Ikemori, Y. and Kodama, Y. (1992): Passive protective effect of chicken egg yolk immunoglobulins against experimental enterotoxigenic Escherichia coli infection in neonatal piglets. Infection and Immunity, March edition, 998-1007.
Yokoyama, H., Hashi, T., Umeda, K., Icatlo, F. C., Kuroki, M., Ikemori, Y. and Kodama, Y. (1997): Reduced intestinal colonization with F18-positive enterotoxigenic Escherichia coli in weaned pigs fed chicken egg antibody against the fimbriae. FEMS Immunology and Medical Microbiology (18), 153-161.

The large majority of poultry specialists in Europe consider phytomolecules as one of the key elements in diets for broilers, broiler breeders, and layers when birds are raised without antibiotics. A quick glance at the market will reveal more commercial products than can possibly be imagined. There are three basic elements you should bear in mind when making your choice:

1. Most phytomolecules are volatile. As such, unprotected products will soon evaporate if left exposed to the open air – as it happens, for instance, with feed prepared in commercial farms. Microencapsulation is therefore essential.
2. There are countless phytomolecules. Consequently, finding the right mix for the task required is essential, as not all mixtures will get you the desired result. When designing a phytomolecule mix, the manufacturer must have the necessary knowledge and experience to achieve the desired result.
3. Phytomolecules are powerful. This is to say that you cannot just keep adding higher quantities to achieve a better result. Finding the exact inclusion rates for the right purpose is a difficult balancing exercise.

In fact, the right protection, the right mix and the right inclusion rates must be combined to ensure that the animals do not refuse the feed (worst case scenario) or just fail to benefit from the inclusion of phytomolecules.

Among the feed additives, phytomolecules (or secondary plant compounds) stand out as a class of active ingredients that may help to improve gut health and thereby reduce the use of antibiotics.  Synthesized by plants as a defense mechanism against pathogens, phytomolecules promote the digestion of feed ingredients (Zhai et al. 2018), prevent loss of gut integrity during enteric challenges (Liu et al. 2018), and have antimicrobial properties that hinder the growth of potential pathogens (Chowdhury, 2018). Phytomolecules can prevent the overgrowth of opportunistic pathogens, thereby reducing the frequency of occurrence of diseases such as necrotic enteritis and dysbacteriosis and thus improve performance data such as daily weight gain and feed efficiency.

Beyond the phytomolecules’ proven effects, what works best in supporting the health and welfare of your animals is, in fact, a holistic program (such as those offered by EW Nutrition) that consists of an effective combination of innovative products and consultancy services in the fields of gut health, nutrition, AMR monitoring, and biosecurity management.

*This article is available in Dutch.

Pigs at birth having insufficient immunity are simply not able to cope with the stress situations they face early in life. They of course become susceptible to the many pathogens common in the farrowing house. The resulting negative effects are added medical costs for treating the pigs and often an increased mortality. Strengthening the immune system by applying egg antibodies (IgY) during the first days of piglet’s life is a proven viable option.

Immunity in pigs

Humans and animals are protected against diseases by specific antibodies (AB). Newborns receive the antibodies maternally (passive immunity) and they produce them after contact with pathogens (active immunity). But unlike humans, who receive maternal AB within the womb, sows possess a multi-layered placenta which prevents the transfer of AB during gestation. Therefore, an early intake of AB from colostrum is essential. This intake should begin immediately after birth as absorption decreases with every hour. But, the maternal antibodies are only a “starter immune kit”. The young pigs immediately must begin to develop their own “active immunity”.

Figure 1: Immune status of the young pig (Sieverding, 2000)

Figure 1 shows gaps of low immunity shortly after birth and about six weeks after, as the level of passive immunity begins to drop and the active immunity starts to build up. The strength of the passive immune protection depends on quantity and quality of the colostrum consumed by the nursery pig. The quality is determined by the pathogens the sows have been confronted with during their life. Young gilts and sows with only short adaptation time into the herd often do not have the farm-specific antibodies needed to pass to their nursing pigs.

How can egg antibodies serve as a tool ? Young pigs are challenged by different pathogens (see figure 2). From studies made by the German internist Felix Klemperer (Klemperer, 1893) we know that hens which come in contact with pathogens (in his studies with tetanus bacillus) produce antibodies against these pathogens. The antibodies are transferred to the egg yolk and are intended for being a starter protection kit for the chicks. Technology allows us today to produce a highly valuable product based on egg powder. It contains significant amounts of natural egg immunoglobulins (IgY – immunoglobulins from the yolk). These egg antibodies mainly act in the gut. There they recognize and tie up pathogens and in this way render them ineffective. Figure 2: Commonly occurring pathogens causing diarrhea in pigs as they age

Not all egg powders are equal

Early work done by Kellner et al. (1994) showed the effectiveness of egg powder containing relevant antibodies against diarrhea causing pathogens in nursery pigs. In the trial they evaluated three groups receiving egg powder with relevant antibodies, egg powder from regular eggs or no additive (negative control).

Results:
(Figure 3: Effects of egg powder with relevant antibodies and egg powder from regular eggs in comparison to a negative control):

• The group that received egg powder containing relevant antibodies completely recovered from diarrhea on day 4.
• In the group fed normal egg powder on day 4 still 9 % suffered from severe diarrhea.
• In the control more than 70 % showed either severe or light diarrhea.

The results show that the effectiveness of egg powder depends on its content of antibodies.

Reducing mortality by oral administration of egg antibodies

The effectiveness of egg antibodies in pigs was demonstrated also in other studies (Erhard et al., 1996, Yokoyama et al., 1992, Nguyen et al., 2005, Yokoyama et al., 1997). One trial conducted in Germany showed promising results concerning reduction of mortality in the farrowing unit. For the trial 96 sows and their litters were divided evenly into three groups (32 sows each) and the pigs were treated as follows:

*EP = Egg powder based product

Results:
Figure 4 shows regardless of the frequency of oral application dosage given to pigs both were very supportive and significantly reduced mortality compared to the control. This resulted in a higher number of weaned pigs than in the control.

Figure 4: Mortality and resulting number of pigs weaned per sow and year

Conclusion

Using egg antibodies in pig nutrition is an effective tool to reduce mortality in young pigs. They can be applied individually by doser (newly weaned pigs) or via powder in the feed. Both practices have proven effectively in commercial operations. To learn more about the application of such technology please contact 1-515-251-7430 or visit our website.

References

Erhard, M.H., Bergmann, J., Renner, M., Hofmann, A. and Heinritzi, K.: Prophylaktische Wirkung von spezifischen Dotterantikörpern bei Escherichia coli K88 (F4)-bedingten Durchfallerkrankungen von Absatzferkeln. J. Vet. Med. A. 43 ; 217-223 (1996).

Kellner, J., Erhard, M.H., Renner, M. and Lösch, U.: Therapeutischer Einsatz von spezifischen Eiantikörpern bei Saugferkeldurchfall – ein Feldversuch. Tierärztliche Umschau 49, Nr.1; 31-34 (1994).

Klemperer, F.: Ueber natürliche Immunität und ihre Verwerthung für die Immunisierungstherapie. Arch. f. Exp. Pathol. Pharmakol. 31, 356-382 (1893)

Nguyen, V. S, Bui, H. N. P. and Nguyen, T. P. N.: Hyperimmunized chicken egg protein improves performance of piglets. Asian Pork Magazine, 18-19; April/May (2005).

Sieverding, E.: Handbuch gesunde Schweine; Kamlage Verlag (2000).

Yokoyama, H., Peralta, R.C., Diaz, R., Sendo, S., Ikemori, Y. and Kodama, Y.: Passive protective effect of chicken egg yolk immunoglobulins against experimental enterotoxigenic Escherichia coli infection in neonatal piglets. Infection and Immunity, 998-1007; Mar. (1992)

Piglets experience significant stress when they are weaned from the sow and change diet, making them susceptible to gastrointestinal disorders. Primarily during the first two weeks after weaning, they are likely to suffer from post-weaning diarrhea (PWD). PWD is a significant problem for pig producers worldwide: it leads to severe dehydration, stunted growth and mortality rates of up to 20-30%. Treatment and additional labor costs further squeeze farm profitability and necessitate unwanted antibiotic interventions.

Zinc oxide: an effective but highly problematic tool

Since the early 1990s zinc oxide (ZnO) has been used to control post-weaning diarrhea and promote growth in piglets, mainly at pharmacological dosages of 2500 to 3000ppm. Its mode of action is still not entirely understood; effects on immune or metabolic processes, altered microbiota, or post-absorptive metabolism are likely to play a role. What is clear is that the use of ZnO in European pig production has strongly increased since the EU banned the use of antibiotic growth promoters such as colistin in 2006 to curb the development of antimicrobial resistance.

Pigs depend on a continuous supply of zinc. Among other roles, this trace element constitutes a functional component of around 300 biochemical enzymes, making it pivotal to most metabolic processes, and by extension to optimal health, production and reproduction.  Modern pig diets thus include zinc supplementation to meet the animals’ requirements. The European Food Safety Authority (EFSA) currently suggests that a total level of 150ppm of zinc in feed matches the animals’ physiological need for zinc. The EFSAs concerns are solely connected to the environmental concerns arising from pharmacological high dosages of ZnO.

These concerns are grave indeed: zinc is a heavy metal after all. Too much zinc is toxic for the animal, hence its physiology ensures that excessive zinc intake is excreted. The bioavailability and absorption of zinc from zinc oxide is particularly low. Therefore most of the zinc given to piglets in this way accumulates in their manure – which is widely used as an organic fertilizer for agricultural soils.

The continual application of manure gradually increases topsoil zinc concentrations; leaching and run-off then lead to contamination of groundwater, surface waters, and sediment. As zinc is non-volatile and non-degradable, it is only a matter of time before concentrations lead to ecotoxic effects, including food crops, aquatic life, and drinking water. Classic mitigation measures such as diluting the manure or keeping certain minimum distances between application areas and surface waters can only slow down the environmental accumulation of zinc, not prevent it.

EU ban: ZnO to be phased out by 2022

In 2017, the European Medicines Agency (EMA) – the EU agency responsible for the scientific evaluation, supervision and safety monitoring of medicines, including veterinary medicinal products – conducted an overall risk-benefit analysis for ZnO. It concluded that the benefits of preventing diarrhea in pigs did not outweigh the significant environmental risks caused by zinc pollution. By June 2022 all EU member states will thus have to withdraw marketing authorizations for veterinary medicinal products containing zinc oxide that are administered orally to food-producing species.

In its decision, the EMA’s Committee for Medicinal Products for Veterinary Use also points out the risk that, due to co-resistance, the use of zinc oxide might promote the development of antimicrobial resistance. High doses of zinc supplementation have been shown to increase the proportion of multidrug-resistant E. coli and Salmonella, two of the most important pathogens in pig production.

What is more, studies show that excessive zinc can accumulate in the liver, the pancreas, and blood serum, and that it permanently reduces the lactobacilli population of the gut flora. With what consequences for performance in the fattening phase? Hence, there are plenty of reasons why getting rid of zinc oxide is a good thing and will ultimately result in even better, more sustainable pig production – but, of course, only if effective replacement strategies to control PWD and boost piglet performance are in place.

Towards zero ZnO: smart feed additives optimize gut health

The search for ZnO alternatives takes us right back to the start, to the piglets’ challenged gastrointestinal tract. During their first three months of life, pigs’ gastrointestinal system undergoes a complex maturation process of its epithelial, immune, and enteric nervous systems. Only once all of these systems are fully developed is the gut capable of delivering its normal functions (digestion, nutrient absorption, immunity, etc.), while also providing an effective barrier against the pathogens, antigens, and toxins in the lumen.

Unlike in nature, where weaning occurs around the time when GIT functions have matured, weaning in commercial pig production takes place during this vulnerable developmental period. Post-weaning diarrhea is ultimately a consequence of intestinal dysbiosis, a state of imbalance in the intestinal microbiome which in turn is induced by the dietary, behavioral, and environmental stressors of the weaning phase (such as separation from the sow, vaccinations, transport, introduction of solid feed).

PWD control thus starts with managing these stressors, which includes ensuring sufficient colostrum intake, gradual feed changes, and meticulous nursery hygiene. Critically, the weaning diet needs to optimally support gut health. Intelligent feed additive solutions are able to

• reduce the pathogenic load in the piglet’s GIT,
• strengthen the piglet’s maturing gut barrier functionality, and
• selectively induce the development of beneficial microorganisms within the microbiome.

A synergistic combination of phytomolecules, medium-chain fatty acids, glycerides of butyric acid, and prebiotics achieves these objectives in a reliable and cost-effective manner. Thanks to their antimicrobial, anti-inflammatory, and digestive properties these selected ingredients effectively support piglets during this critical phase of their postnatal gut development, while also boosting their feed intake.

In the past decade, the European pig sector has successfully adapted to the 2006 ban on antibiotic growth promoters through significant improvements in management and feed practices. Cutting out zinc oxide is an ambitious challenge – but with the support of targeted, functional feed additives, producers will be able to set their piglets up for a strong, sustainable, zero ZnO health and growth performance.

*You can find this article in polish and italian.

References

Amezcua, Rocio, Robert M. Friendship, Catherine E. Dewey, Carlton Gyles, and John M. Fairbrother. “Presentation of postweaning Escherichia coli diarrhea in southern Ontario, prevalence of hemolytic E. coli serogroups involved, and their antimicrobial resistance patterns.” Canadian Journal of Veterinary Research 66, no. 2 (April 2002): 73-8. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC226986/.

Bednorz, Carmen, Kathrin Oelgeschläger, Bianca Kinnemann, Susanne Hartmann, Konrad Neumann, Robert Pieper, Astrid Bethe, et al. “The Broader Context of Antibiotic Resistance: Zinc Feed Supplementation of Piglets Increases the Proportion of Multi-Resistant Escherichia Coli in Vivo.” International Journal of Medical Microbiology 303, no. 6-7 (2013): 396–403. https://doi.org/10.1016/j.ijmm.2013.06.004.

Brugger, Daniel, and Wilhelm M. Windisch. “Strategies and Challenges to Increase the Precision in Feeding Zinc to Monogastric Livestock.” Animal Nutrition 3, no. 2 (March 24, 2017): 103–8. https://doi.org/10.1016/j.aninu.2017.03.002.

Burrough, Eric R., Carson De Mille, and Nicholas K. Gabler. “Zinc Overload in Weaned Pigs: Tissue Accumulation, Pathology, and Growth Impacts.” Journal of Veterinary Diagnostic Investigation 31, no. 4 (June 6, 2019): 537–45. https://doi.org/10.1177/1040638719852144.

De Mille, Carson, Emma T. Helm, Eric R. Burrough, and Nicholas K. Gabler. “Zinc oxide does not alter ex vivo intestinal integrity or active nutrient transport in nursery pigs.” Paper presented at the Zero Zinc Summit, Copenhagen, Denmark, June 17-18, 2019. https://svineproduktion.dk/Services/-/media/3E0A1D2A4CAC409FAA6212B91DFEA537.ashx.

Moeser, Adam J., Calvin S. Pohl, and Mrigendra Rajput. “Weaning Stress and Gastrointestinal Barrier Development: Implications for Lifelong Gut Health in Pigs.” Animal Nutrition 3, no. 4 (December 2017): 313–21. https://doi.org/10.1016/j.aninu.2017.06.003.

Rhouma, Mohamed, Francis Beaudry, William Thériault, and Ann Letellier. “Colistin in Pig Production: Chemistry, Mechanism of Antibacterial Action, Microbial Resistance Emergence, and One Health Perspectives.” Frontiers in Microbiology 7 (November 11, 2016): Article 1789. https://doi.org/10.3389/fmicb.2016.01789.

Starke, Ingo C., Robert Pieper, Konrad Neumann, Jürgen Zentek, and Wilfried Vahjen. “The Impact of High Dietary Zinc Oxide on the Development of the Intestinal Microbiota in Weaned Piglets.” FEMS Microbiology Ecology 87, no. 2 (February 1, 2014): 416–27. https://doi.org/10.1111/1574-6941.12233.