The European Environment Agency (EEA) has recently published a briefing detailing the impact of veterinary antimicrobials on Europe’s environment. Positive developments are to be applauded, however they do not tell the whole story.

The use of antimicrobials for farmed animals and in aquaculture decreased by around 28% between 2018 and 2022. Nonetheless, the rate of antimicrobial resistance continues to rise around the world, including as an important cause of death in the European Economic Area (the EEA includes all EU countries, as well as Norway, Lichtenstein, and Iceland). At present, antimicrobial-resistant infections are estimated to caused 35,000 deaths per year in the European Union. For reference, in the EU, traffic accidents cause around 20,000 deaths per year.

A large number of EU guidelines, policies, and regulations attempt to control and monitor the use of antimicrobials in food-producing animals. This makes the regulatory landscape somewhat confusing, especially that many implementation details are still left to the states.

Figure 1. Overview of the EU regulatory framework applicable to antimicrobials used in food-producing animals

One of the results of unequal implementation is that there is no standardized way of tracking the actual use of antimicrobials in food-producing animals. To collect the numbers, the EEA has used proxy numbers, especially antimicrobial sales data and self-reported data. With such broad strokes, it is to be expected that the actual figures might be higher.

Lower numbers…

According to the European Surveillance of Veterinary Antimicrobial Consumption (ESVAC) database, in the European Economic Area countries, plus Switzerland and the UK, total antimicrobial consumption for farmed animals and aquaculture was estimated at 73.9 mg/PCU* in 2022. This signifies a 30% reduction over 5 years.

In numbers: 4,458 tons of active substances were sold in one years for farmed animals & aquaculture.

*PCU represents a population correction unit (PCU). The PCU takes into account the population and relative weight of animals and “is used the normalize antimicrobial sales data for the size of the animal population that could potentially be treated with these substances. Using this methodology, 1 PCU corresponds to 1 kilogram of animal biomass”.

…But higher risks

In 2021, total antimicrobial consumption in humans – measured in 28 European countries – was estimated at 125.0 mg/kg. This number has unfortunately not gone down. What is worse: a much larger volume of antimicrobials is sold for food-producing animals than for human medicine. Which means that, relative to the total population, the impact of veterinary-use antimicrobials remains disproportionately large.

Moreover, two outliers (Poland and Lithuania) exhibited a worrying increasing trend, showing that no good development is irreversible. The EEA also highlights this danger, in the context of growing global consumption of animal protein. Increased demand “may put pressure on farmers to adopt intensive production practices that require increased use of antimicrobials”. The use of antimicrobials elsewhere in the world may lead to impacts in Europe, “not just by theoretically exposing consumers to antimicrobial residues but also by contributing to rising global rates of drug-resistant pathogens and infections”.

Figure 2. Sales by EU Member States in 2018 vs. 2022

Because of declining livestock populations in the last few years, while demand remained constant, EU-27 imports of animal products more than doubled between 2002 and 2022. There are no reliable global data on the veterinary use of antimicrobials, however it is generally believed that over 70% of antimicrobials sold globally may be used in for animal protein production.

Data collected by the World Organization for Animal Health (WOAH) from its member countries suggest that, between 2017-2019, “the use of antimicrobials in animals decreased by 25% in the Asia, Far East and Oceania regions, while it increased in Africa (+45%) and the Americas (+5%). Despite these partial improvements, a recent study forecasted that global use of antimicrobials in food-producing animals could rise by 8% in 2030, compared to 2020 levels (Mulchandani et al., 2023)”.

Quick summary

Reduction in Antimicrobial Use: There has been a significant reduction in the use of antimicrobials in farming and aquaculture across the EU. From 2018 to 2022, there was a decrease of approximately 28%, which aligns with the EU’s Farm to Fork strategy targeting a 50% reduction by 2030.

Antimicrobial Resistance (AMR): Despite the decrease in use, antimicrobial resistance remains a severe public health threat, causing an estimated 35,000 deaths annually in the European Economic Area. The resistance is attributed to the use of antimicrobials, which – as has been widely documented and discussed – can promote the evolution of resistant microorganisms.

Environmental Impact: The briefing underscores significant knowledge gaps in monitoring antimicrobial residues, resistant bacteria, and resistance genes in the environment. Improved surveillance could help identify pollution hotspots and assess the impact of reduction measures.

Regulatory and Policy Framework: The EU has implemented several policies to regulate the use of antimicrobials, including banning their use as growth promoters and setting stricter conditions for prescriptions. These measures are crucial for managing the risk of AMR.

Further efforts are needed to decrease the reliance on antimicrobials in food production. These include enhanced monitoring, promoting alternative practices in animal farming, and better animal welfare and biosecurity measures.

While improvements are clear and commendable in the EU-27 states, increased antimicrobial usage in some EU countries and in various areas around the world represent a significant concern.

For further details on the use of veterinary antimicrobials in Europe’s environment, you can refer to the EEA’s full report.

Author: Ajay Bhoyar, Global Technical Manager, EW Nutrition

Exogenous feed enzymes are increasingly utilized in poultry diets to manage feed costs, mitigate the adverse effects of anti-nutritional factors, and enhance nutrient digestion and bird performance. These enzymes are primarily employed to bolster the availability of nutrients within feed ingredients. Among the various enzymes utilized, those capable of breaking down crude fiber, starch, proteins, and phytates are commonly integrated into animal production systems.

In monogastric animals such as poultry and swine, a notable deficiency exists in the endogenous synthesis of enzymes necessary for the hydrolysis of non-starch polysaccharides (NSPs) like xylan (McLoughlin et al., 2017). This deficiency often manifests in poultry production as a decline in growth performance, attributed to increased digesta viscosity arising from the prevalence of NSPs in commonly utilized poultry feed ingredients. Without sufficient endogenous enzymes to degrade xylan, NSPs can increase digesta viscosity, encase essential nutrients, and create a barrier to their effective digestion. In response to this issue, monogastric animal producers have implemented exogenous enzymes such as xylanases into the feeds for swine and poultry to degrade xylan to short-chain sugars, thus reducing intestinal viscosity and improving the digestive utilization of nutrients (Sakata et al., 1995; Aragon et al., 2018)

Understanding Xylanase Enzymes

Xylanase enzymes belong to the class of carbohydrases that specifically target complex polysaccharides, such as xylan, a backbone nonstarch polysaccharide (NSP) prevalent in plant cell walls. These enzymes catalyze the hydrolysis of xylan into smaller, more digestible fragments, such as arabino–xylo-oligosaccharides (AXOs) and xylo-oligosaccharides (XOs), thereby facilitating the breakdown of dietary fiber in poultry diets.

Mechanism of action

It is generally agreed that the beneficial effects of feed xylanase are primarily due to the reduction in viscosity. Studies have shown that supplementing xylanases to animal feeds reduces digesta viscosity and releases encapsulated nutrients, thus improving the overall feed digestibility and nutrient availability (Matthiesen et al., 2021). The reduction in digesta viscosity by adding xylanase is achieved by the partial hydrolysis of NSPs in the upper digestive tract, leading to a decrease in digesta viscosity in the small intestine (Choct & Annison, 1992).

GH10 vs. GH11 Xylanases

Well-characterized xylanases are mostly grouped into glycoside hydrolase families 10 (GH10) and 11 (GH11) based on their structural characteristics (amino acid composition), mode of xylan degradation, the similarity of catalytic domains, substrate specificities, optimal conditions, thermostability, and practical applications.

Why are GH10 xylanases more efficient in animal production?

While both GH10 and GH11 xylanases act on the xylan main chain, these two enzyme types have different folds, substrate specificities, and mechanisms of action (Biely et al., 2016). The GH10 xylanases are more beneficial in animal feed production due to their efficient mechanism of action, broader substrate specificity, and better thermostability, as discussed below.

GH10 xylanase exhibits broader substrate specificity

Generally, the GH10 xylanases exhibit broader substrate specificity and can hydrolyze various forms of xylan, including soluble and insoluble substrates. On the other hand, GH11 xylanases have a narrower substrate specificity and are primarily active on soluble xylan substrates. GH10 xylanases exhibit higher catalytic versatility and can catalyze the cleavage of the xylan backbone at the nonreducing side of substituted xylose residues, whereas GH11 enzymes require unsubstituted regions of the xylan backbone (Collins et al., 2005; Chakdar et al., 2016).

As a result, GH10 xylanases generally produce shorter xylo-oligosaccharides than members of the GH11 family (Collins et al., 2005). Moreover, as shown in Fig.1, the GH10 xylanase can rapidly and effectively break down xylan molecules.

Fig.1.: Activity of a bacterial GH10 xylanase against soluble and insoluble arabinoxylans

Higher thermostability

Enzymes are proteins, and the protein’s primary structure determines their thermostability. The enzyme protein tends to denature at higher than tolerable temperatures, rendering it inactive. An enzyme’s high-temperature tolerance ensures its efficacy throughout the pelleted feed manufacturing. This results in consistent enzyme activity in the finished feed, subsequent gut health, and predictable performance benefits.

Xylanases with higher thermostability are more suitable for applications requiring high-temperature processes. An intrinsically heat-stable bacterial xylanase maintains its activity even under high-temperature feed processing conditions, such as pelleting.

A study conducted at the University of Novi Sad, Serbia (Fig. 2), with three pelleting temperatures (85 °C, 90 °C, and 95 °C) and conditioning times of 4 and 6 mins, showed that Axxess XY, an intrinsically thermostable GH10 xylanase, demonstrated more than 85% recovery even at 4 to 6 mins conditioning time and 95 °C temperature.

Fig.2: Optimum recovery of Axxess XY at elevated conditioning time and temperatures

Maintaining consistently optimum enzyme activity is crucial for realizing the benefits of enzyme inclusion in feed under challenging feed processing conditions.

Conclusion

In conclusion, exogenous feed enzymes, including xylanase, have gained widespread recognition for their pivotal role in poultry nutrition. The increasing use of xylanase is attributed to its ability to effectively manage feed costs while incorporating high-fiber ingredients without compromising poultry performance. However, the efficacy of xylanase is based on several factors, including its mode of action, substrate specificity, catalytic efficacy, and thermostability. Selecting the appropriate xylanase enzyme tailored for specific needs is crucial to harnessing its full benefits.

A GH10 xylanase, such as Axxess XY, designed explicitly as a feed enzyme, offers distinct advantages in poultry production. Its efficient mechanism of action, broader substrate specificity, and superior thermostability make it a preferred choice for optimizing animal performance. Notably, Axxess XY exhibits exceptional activity against soluble and insoluble arabinoxylans, thereby enhancing nutrient utilization, promoting gut health, and ultimately elevating overall performance levels in poultry.

Incorporating specialized GH10 Xylanase enzymes like Axxess XY represents a strategic approach to unlocking the nutrients in feedstuffs, ensuring optimal performance, and maximizing profitability in the poultry business.

References

Aragon, Caio C., Ana I. Ruiz-Matute, Nieves Corzo, Rubens Monti, Jose M. Guisán, and Cesar Mateo. “Production of Xylo-Oligosaccharides (XOS) by Controlled Hydrolysis of Xylan Using Immobilized Xylanase from Aspergillus Niger with Improved Properties.” Integrative Food, Nutrition and Metabolism 5, no. 4 (2018). https://doi.org/10.15761/ifnm.1000225.

Bedford, Michael R., and Henry L. Classen. “Reduction of Intestinal Viscosity through Manipulation of Dietary Rye and Pentosanase Concentration Is Effected through Changes in the Carbohydrate Composition of the Intestinal Aqueous Phase and Results in Improved Growth Rate and Food Conversion Efficiency of Broiler Chicks.” The Journal of Nutrition 122, no. 3 (March 1992): 560–69. https://doi.org/10.1093/jn/122.3.560.

Biely, Peter, Suren Singh, and Vladimír Puchart. “Towards Enzymatic Breakdown of Complex Plant Xylan Structures: State of the Art.” Biotechnology Advances 34, no. 7 (November 2016): 1260–74. https://doi.org/10.1016/j.biotechadv.2016.09.001.

Chakdar, Hillol, Murugan Kumar, Kuppusamy Pandiyan, Arjun Singh, Karthikeyan Nanjappan, Prem Lal Kashyap, and Alok Kumar Srivastava. “Bacterial Xylanases: Biology to Biotechnology.” 3 Biotech 6, no. 2 (June 30, 2016). https://doi.org/10.1007/s13205-016-0457-z.

Choct, M., and G. Annison. “Anti‐nutritive Effect of Wheat Pentosans in Broiler Chickens: Roles of Viscosity and Gut Microflora.” British Poultry Science 33, no. 4 (September 1992): 821–34. https://doi.org/10.1080/00071669208417524.

Collins, Tony, Charles Gerday, and Georges Feller. “Xylanases, Xylanase Families and Extremophilic Xylanases.” FEMS Microbiology Reviews 29, no. 1 (January 2005): 3–23. https://doi.org/10.1016/j.femsre.2004.06.005.

Matthiesen, Connie F., Dan Pettersson, Adam Smith, Ninfa R. Pedersen, and Adam. C. Storm. “Exogenous Xylanase Improves Broiler Production Efficiency by Increasing Proximal Small Intestine Digestion of Crude Protein and Starch in Wheat-Based Diets of Various Viscosities.” Animal Feed Science and Technology 272 (February 2021): 114739. https://doi.org/10.1016/j.anifeedsci.2020.114739.

McLoughlin, Rebecca F, Bronwyn S Berthon, Megan E Jensen, Katherine J Baines, and Lisa G Wood. “Short-Chain Fatty Acids, Prebiotics, Synbiotics, and Systemic Inflammation: A Systematic Review and Meta-Analysis.” The American Journal of Clinical Nutrition 106, no. 3 (March 2017): 930–45. https://doi.org/10.3945/ajcn.117.156265.

Sakata, T., M. Adachi, M. Hashida, N. Sato, and T. Kojima. “Effect of N-Butyric Acid on Epithelial Cell Proliferation of Pig Colonic Mucosa in Short-Term Culture.” DTW – Deutsche Tierärztliche Wochenschau 102, no. 4 (1995): 163–64.

By Dr. Ajay Bhoyar, Global Technical Manager, EW Nutrition

In modern, intensive poultry production, the imminent threat of resistant Eimeria looms large, posing a significant challenge to the sustainability of broiler operations. Eimeria spp., capable of developing resistance to our traditional interventions, has emerged as a pressing global issue for poultry operators. The resistance of Eimeria to conventional drugs, coupled with concerns over drug residue, has necessitated a shift towards natural, safe, and effective alternatives.

Several phytogenic compounds, including saponins, tannins, essential oils, flavonoids, alkaloids, and lectins, have been the subject of rigorous study for their anticoccidial properties. Among these, saponins and tannins in specific plants have emerged as powerful tools in the fight against these resilient protozoa. In the following, we delve into innovative strategies that leverage the potential of these compounds, particularly saponins and tannins, to prevent losses by mitigating the risk of resistant Eimeria in poultry production.

Understanding resistant Eimeria in broiler production

The World Health Organization Scientific Group (World Health Organization, 1965) developed the definition of resistance in broad terms as ‘the ability of a parasite strain to survive and/or to multiply despite the administration and absorption of a drug given in doses equal to or higher than those usually recommended but within the limits of tolerance of the subject’.

The high reproduction rate of Eimeria spp. allows them to evolve quickly and develop resistance to drugs used for their control. Moreover, the resistant strains of Eimeria can persist in the environment due to their ability to form resistant oocysts, leading to the re-infection of animals and further spread of resistant strains.

Resistant Eimeria strains present many challenges in modern poultry farming, significantly impacting overall productivity and economic sustainability. However, one of the primary challenges is the reduced efficacy of traditional anti-coccidial drugs.

Eimeria resistance occurs in different types

There are different possibilities as to why Eimeria are resistant to specific drugs.

Acquired resistance results from heritable decreases in the sensitivity of specific strains and species of Eimeria to drugs over time. There are two types of acquired resistance: partial and complete. These types depend upon the extent of sensitivity lost. There is a direct relationship between the concentration of the drug and the degree of resistance. A strain controlled by one drug dose may show resistance when a lower concentration of the same drug is administered.

Cross-resistance is the sharing of resistance among different compounds with similar modes of action (Abbas et al., 2011). This, however, may not always occur (Chapman, 1997).

Multiple resistance is resistance to more than one drug, even though they have different modes of action (Chapman, 1993).

Natural substances can bring back the efficacy of anticoccidial measures

It was found that if a drug to which the parasite has developed resistance is withdrawn from use for some time or combined with another effective drug, the sensitivity to that drug may return (Chapman, 1997).

Botanicals and natural identical compounds are well renowned for their antimicrobial and antiparasitic activity, so they can represent a valuable tool against Eimeria (Cobaxin-Cardenas, 2018). The mechanisms of action of these molecules include degradation of the cell wall, cytoplasm damage, ion loss with reduction of proton motive force, and induction of oxidative stress, which leads to inhibition of invasion and impairment of Eimeria spp. development (Abbas et al., 2012; Nazzaro et al., 2013). Natural anticoccidial products may provide a novel approach to controlling coccidiosis while meeting the urgent need for control due to the increasing emergence of drug-resistant parasite strains in commercial poultry production (Allen and Fetterer, 2002).

Saponins and Tannins: Nature’s Defense against Eimeria Challenge

Phytogenic solutions, specifically those based on saponins and tannins, have recently surfaced as promising alternatives to mitigate the Eimeria challenge in poultry production. By harnessing the power of these natural compounds, poultry producers can boost the resilience of their flocks against the Eimeria challenge, promoting both the birds’ welfare and the industry’s sustainability.

Saponins are glycosides found in many plants with distinctive soapy characteristics due to their ability to foam in water. In the context of Eimeria, saponins can disrupt the integrity of the parasites’ cell membranes. When consumed, saponins can interfere with the protective outer layer of Eimeria, weakening the parasite and rendering it vulnerable to the host’s immune responses. This disruption impedes the ability of Eimeria to attach to the intestinal lining and reproduce, effectively curtailing the infection.

Tannins are polyphenolic compounds with astringent properties, occurring in various plant parts, such as leaves, bark, and fruits. Choosing the proper tannin at the right level and time is crucial to realize the benefits of tannin-based feed additives.

In the context of Eimeria, tannins exhibit several mechanisms of action. Firstly, they bind to proteins within the parasites, disrupting their enzymatic activities and metabolic processes. This interference weakens Eimeria, hindering its ability to cause extensive damage to the intestinal lining. Secondly, tannins are anti-inflammatory, reducing the inflammation caused by Eimeria infections. Additionally, tannins act as antioxidants, protecting the intestinal cells from oxidative stress induced by the parasite.

When incorporated into broilers’ diets, saponins and tannins create an unfavorable environment for Eimeria, inhibiting their growth and propagation within the host. Moreover, these compounds fortify the broiler’s natural defenses, enhancing its ability to resist Eimeria infections. By leveraging the innate properties of saponins and tannins, the impact of resistant Eimeria strains can effectively be managed and mitigated, fostering healthier flocks and sustainable poultry production.

What is Pretect D?

Pretect D is a unique proprietary blend of phytomolecules, including saponins and tannins, that supports the control of coccidiosis challenges in poultry production. It can be used alone or in combination with coccidiosis vaccines, ionophores, and chemicals as part of a shuttle or rotation program.

Fig.1. Key active ingredients of Pretect D

Modes of action of Pretect D

Pretect D exhibits multiple modes of action to optimize gut health during challenging times. Due to its anti-protozoal, anti-inflammatory, immunomodulatory, and antioxidant properties, it

1. effectively decreases oocyst excretion and disease spread
2. promotes restoring the mucosal barrier function and improves intestinal morphology
3. protects the intestinal epithelium from inflammatory and oxidative damage.

The beneficial effects of Pretect D

The beneficial effects of Pretect D’s inclusion in the coccidiosis control program include improving overall gut health and broiler production performance.

In a challenge study with Cobb 500 broiler chicks under a mixed Eimeria inoculum challenge, it was evident that the group receiving Pretect D (@500g/ton) in the feed throughout the 35-day rearing period had less coccidia-caused lesions (D27) than the broilers challenged and fed control diets.

Fig. 2: Pretect D reduced coccidia-caused lesions in broilers

In another field study, a traditional anticoccidial program (Starter and Grower I feeds: Narasin + Nicarbazin, Grower II feed: Salinomycin, Finisher/ withdrawal feeds: No anticoccidial) was compared with a program combining anticoccidials with Pretect D (Starter and Grower I feeds: Narasin + Nicarbazin, Grower II and Finisher feeds: Pretect D). The addition of Pretect D significantly reduced OPG count and lowered the coccidiosis lesion score compared to the control (Fig. 3).

Fig.3. Pretect D reduced broilers’ coccidiosis lesion score and OPG count

Consequently, broilers receiving Pretect D showed better overall production performance.

Fig. 4. Overall improved production performance by Pretect D

Pretect D: Application Strategies

The introduction of an effective phytogenic combination in the coccidiosis control program can help mitigate the drug resistance issue. Such a natural anticoccidial solution can be used as a standalone, preferably in less challenging months, as well as in combination with chemicals (shuttle/ rotation) or a coccidiosis vaccine (bio-shuttle), reducing the need for frequent drug use.

Shuttle programs are commonly employed for managing coccidiosis, and they yield a satisfactory level of success. Within these programs, multiple drugs from distinct classes of anticoccidials are administered throughout a single flock. For instance, one class of drug is utilized in the starter feed, another in the grower stage, reverting to the initial class for the finisher diet and concluding with a withdrawal period.

In rotation programs, anticoccidial drugs are alternated between batches rather than within a single batch.

Conclusions

Coccidiosis is considered one of the most economically significant diseases of poultry and the development of anticoccidial resistance has threatened the profitability of the broiler industry. Therefore, regularly monitoring Eimeria species to develop resistance against different anticoccidial groups is crucial to managing resistance and choosing an anticoccidial. It would be rewarding to use an effective phytogenic solution in the coccidiosis control program as a strategic and tactical measure and to focus on such integrated programs for drug resistance management in the future.

References:

Abbas, R.Z., D.D. Colwell, and J. Gilleard. “Botanicals: An Alternative Approach for the Control of Avian Coccidiosis.” World’s Poultry Science Journal 68, no. 2 (June 1, 2012): 203–15. https://doi.org/10.1017/s0043933912000268.

Abbas, R.Z., Z. Iqbal, D. Blake, M.N. Khan, and M.K. Saleemi. “Anticoccidial Drug Resistance in Fowl Coccidia: The State of Play Revisited.” World’s Poultry Science Journal 67, no. 2 (June 1, 2011): 337–50. https://doi.org/10.1017/s004393391100033x.

Allen, P. C., and R. H. Fetterer. “Recent Advances in Biology and Immunobiology ofEimeriaSpecies and in Diagnosis and Control of Infection with These Coccidian Parasites of Poultry.” Clinical Microbiology Reviews 15, no. 1 (January 2002): 58–65. https://doi.org/10.1128/cmr.15.1.58-65.2002.

Chapman, H. D. “Biochemical, Genetic and Applied Aspects of Drug Resistance inEimeriaParasites of the Fowl.” Avian Pathology 26, no. 2 (June 1997): 221–44. https://doi.org/10.1080/03079459708419208.

Chapman, H.D. “Resistance to Anticoccidial Drugs in Fowl.” Parasitology Today 9, no. 5 (May 1993): 159–62. https://doi.org/10.1016/0169-4758(93)90137-5.

Cobaxin-Cárdenas, Mayra E. “Natural Compounds as an Alternative to Control Farm Diseases: Avian Coccidiosis.” Farm Animals Diseases, Recent Omic Trends and New Strategies of Treatment, March 21, 2018. https://doi.org/10.5772/intechopen.72638.

Nazzaro, Filomena, Florinda Fratianni, Laura De Martino, Raffaele Coppola, and Vincenzo De Feo. “Effect of Essential Oils on Pathogenic Bacteria.” Pharmaceuticals 6, no. 12 (November 25, 2013): 1451–74. https://doi.org/10.3390/ph6121451.

Pop, Loredana Maria, Erzsébet Varga, Mircea Coroian, Maria E. Nedișan, Viorica Mircean, Mirabela Oana Dumitrache, Lénárd Farczádi, et al. “Efficacy of a Commercial Herbal Formula in Chicken Experimental Coccidiosis.” Parasites & Vectors 12, no. 1 (July 12, 2019). https://doi.org/10.1186/s13071-019-3595-4.

World Health Organization Technical Report Series No. 296, (1965) pp:. 29.

by Madalina Diaconu, Global Manager Gut Health, EW Nutrition

In practical poultry production, multiple stress factors occur simultaneously: nutrition, management, environment, etc.. The effects of these factors are additive, leading to chronic stress, a condition in which animals cannot regain homeostasis and continuously deviate the use of resources to inflammation and restoring the gut barrier-function (Das et al., 2011). As a result, the gut microbiome is altered and oxidative stress ensues (Mishra et al., 2019). In this situation, health and productivity are compromised.

The feed supplied to production animals is designed to help them express their genetic potential. However, some feed components are also continuous inflammatory triggers. Anti-nutritional factors, oxidized lipids, and mycotoxins induce a low-grade inflammatory response (Cardoso Del Pont et al., 2020). Other factors that trigger gut health issues include the environment, management, and pathogens.

Feed interventions have shown to increase productivity and improve gut-related biomarkers, demonstrating a mitigation effect over the challenge factors (Deminicis et al., 2020; Latek et al., 2022).

Meta-analysis of broiler studies shows consistent results

As broilers are continuously challenged during the production period, the effects of an in-feed phytogenic (Ventar D – EW Nutrition GmbH) were extensively researched in broiler meat production. 21 trials in different locations (7 in Europe, 6 in the USA, 4 in Japan, 3 in Middle East, and 2 in India), with different production levels (grouped by EPEF) and challenges were analyzed to establish Ventar D’s benefits for the broiler production industry in terms of performance and sustainability. In all trials, the treatment group consisted of a supplementation of the basal feed with Ventar D at a dose 100 g/ton. The control groups were not supplemented with any gut health improvement feed additive.

Of these 21 trials, 14 had corn/soybean meal-based diets and 7 had high fiber diets (based on wheat and rye, which constituted a challenge as no NSP-enzymes were included). Reused litter (by 12 to 14 flocks, previous to the trial) also was used as a challenge. 18 trials were performed in research facilities and 3 in commercial farms.

Consistency in the results from Ventar D could be demonstrated as 19 out of 21 trials showed an improvement in FCR, lowering 3.4 points on average; 18 /21 trials showed higher body weight, with an average of 64 grams more; and 17 trials showed lower mortality than the control group, averaging 1.19 percentual points of reduction. The phenolic compounds included in Ventar D, such as thymol, possess antioxidant, anti-inflammatory, and antibacterial activities, which account for improving gut health and thus increasing performance in production animals.

The European Poultry Efficiency Factor (EPEF) was used to establish the performance level of each flock. This index is based on the average daily weight gain, mortality, and feed conversion, and takes in consideration the age of the flock at collection, allowing to make comparisons on performance within and between farms.

Of the 21 trials, 10 control groups had an EPEF lower than 375, and were considered of low performance level, in 8 the EPEF was between 375 and 425 and considered of medium performance, and for 3 the performance was considered high having an EPEF of 425 or more.

Ventar D increased performance at all levels (Figure 1). However, the effects were challenge-dependent:
Low performing flocks averaged an 8% increase in EPEF, and high performing flocks increased 4%, indicating that Ventar D can help broilers to overcome challenges commonly found in poultry production, and boost performance even with excellent farm and management conditions. These results concur with a meta-analysis by Valle Polycarpo and collaborators (2022), finding that a microbial challenge can influence the performance of phytogenic feed additives.

Overall, this analysis demonstrates that effective nutritional interventions can give consistent results and constitute effective tools to help production animals overcome stress and enhance productivity.

Part 1: Impact on Feathering

By Dr. Inge Heinzl, Editor, EW Nutrition

Mycotoxins are known to decrease health and performance in poultry production. Their modes of action, such as reducing protein synthesis and promoting oxidative stress and apoptosis, lead to cell destruction and lower cell replacement, affecting several organs and tissues.

When different stress factors collude, such as high temperatures and humidity, poor ventilation, high stocking density, and management events, the effects of in-feed mycotoxins can reach a higher level, which may include external signs.

The most common and recognized external sign of mycotoxicosis is mouth lesions caused by trichothecenes, which are highly associated with the presence of T-2 in the feed. However, other signs may appear, such as paleness of combs, shanks, and feet, as well as leg problems, ruffled feathers and poor feather coverage, feed passage, and abnormal feces.

In a series of articles, we want to report on external signs facilitating a differential diagnosis of mycotoxin contamination. This is necessarily followed by feed or raw material mycotoxin analysis and strategies to avoid or mitigate the effects of mycotoxin contamination in poultry production. In the first article, we will cover feathers.

A healthy plumage is crucial for growth and reproduction

Feathering is a crucial aspect of poultry health and productivity. Feathers are essential for thermoregulation, locomotion, adequate skin protection, and reproductive success, protecting hens from injury during mating. Inadequate feathering can lead to lower feed efficiency (Leeson and Walsh, 2004) as well as loss in fertility and chick production (Fisher, 2016). Mycotoxins in poultry feed can compromise feather quality in poultry production animals. This first article delves into the relationship between mycotoxins and poor feathering, exploring different mycotoxins and their mechanisms of action.

In which way do mycotoxins compromise feathering?

On the one hand, chronic mycotoxin exposure impairs the digestive process, hindering the absorption and utilization of vital nutrients essential for feather growth. This disruption can lead to malnutrition, directly impacting the quality and health of feathers. On the other hand, mycotoxins also interfere with metabolic processes critical for feather development, such as keratin synthesis (Wyatt et al., 1975;  Nguansangiam, 2004). Enzymatic pathways involved in synthesizing keratin, the protein building block of feathers, are particularly vulnerable to mycotoxin-induced disruptions. The presence of mycotoxins in feed has been associated with the manifestation of sparse feathering and the sticking out of feathers at an unnatural angle (Emous and Krimpen, 2019). In the case of multiple mycotoxins occurring in the feed, even at singularly unimportant concentrations, a negative impact on feathering is possible. Different mycotoxins have different target organs and consequences for the animal, so their ways of compromising feathering also vary. As feathering needs protein availability, all mycotoxins affecting the protein metabolism or the absorption of nutrients also impact the feathering process. Let us look at the most prominent mycotoxins.

1.   T-2 toxin

Due to climate change, T-2 toxins are on the rise. In the US, more than 50% of the tested samples contained T-2 toxin; in Europe, we found it in 31%, and in China, in 82% of the samples (EW Nutrition, 2024). The highest level was found in Europe, with 850 ppb.

Adverse effects of T-2 toxin in goslings were shown by Gu et al. (2023), who exposed the animals to 6 different levels of T-2 toxin, from 0.2 to 2.0 mg T-2 toxin/kg of feed. The goslings showed a sparse covering with short, dry, rough, curly, and gloss-free feathers on their back with dosages ≥0.8 mg/kg. When zooming on, T-2 can cause necroses of the layer of regenerative cells in the feather base, implying malformation or absence of new feathers, as well as structural damage to existing feathers on the base of the ramus and barb ridges (Hoerr et al. (1982), Leeson et al. (1995)).

The effects in feather regenerative cells are dose-dependent, as confirmed by Hoerr et al. (1982), who applied different doses of T-2 toxin (1.5, 2, 2.5, and 3 mg/kg body weight/day) to 7-day-old broilers for 14 days. Delayed feather development, especially at high dosages, was noticed, as well as malformations and opaque bands in the feathers, the latter probably caused by a segmental reduction in diameter.

Manafi et al. (2015) noticed feather malformations when broiler chickens were challenged with 0.5 ppm T-2 toxin in the feed in combination with an inoculation of 2.4×10⁸ cfu Mycoplasma gallisepticum. When the chickens were challenged only with T-2 toxin, the feathers were ruffled, showing that a coincidence of stress factors even aggravates the symptoms.

2.   Aflatoxins

Aflatoxins, produced by certain Aspergillus species, are among the most notorious mycotoxins. Looking at test results of the last year, Aflatoxin shows incidences between 25 (USA) over 40-65% (Europe, LATAM, MEA, and SEAP) up to 84-88% (China and South Asia) with average levels up to 42 ppb in South Asia (EW Nutrition, 2023). However, more information about the concrete impact of aflatoxins on feathering is needed. They may indirectly affect feathering because they impact digestion and the utilization of nutrients or trace minerals such as zinc, which is essential for the feather construction process. Damage to the liver impacts protein metabolism, and keratin is also necessary for feather production.

In other studies, Muhammad et al. (2017) fed 5 mg AFB1/kg to Arbor Acres broilers, and the birds showed ruffled feathers. A significantly lower feather shine was noticed by Saleemi et al. (2020) when they gave the animals 300 μg AFB1/kg of feed, and the birds of Zafar et al. (2017) showed ruffled, broken, dull, and dirty feathers after six weeks of feeding an aflatoxin-contaminated diet.

3.   Ochratoxin

Ochratoxins, commonly produced by Aspergillus and Penicillium fungi, also pose a significant threat to poultry. When looking at the mycotoxin report, this mycotoxin was found in 16% (Europe) to 70% (SEAP) of the samples (EW Nutrition, 2023). Ochratoxins primarily affect feathering by compromising the structural integrity of feathers and causing delayed feathering in broilers (Leeson, 2021).

Several trials have shown the negative impact of ochratoxin on feather quality. Hassan et al. (2010) fed OTA to laying hens and saw a dose-dependent (dosages from 0 to 10 mg/kg feed) occurrence of ruffled and broken feathers in the OTA group, whereas the plumage of the control group was shiny and well-formed. Hameed et al. (2012) also realized dull feathers when feeding 0.4 and 0.8 mg OTA per kg of feed. A further dose-dependent decrease in feather quality was described by Khan et al. (2023) in broiler chicks. He injected them with dosages from 0.1 to 1.7 mg/kg body weight on day 5 of age and saw a deterioration of feather appearance (rippled feathers) in the groups with the higher dosages of 1.3 and 1.7 mg/kg. Abidin et al. (2016) observed a similar dose-dependent deterioration of the feather quality in white Leghorn cockerels when feeding 1 or 2mg OTA/kg feed.

Combinations of aflatoxins and ochratoxins were also tested. Khan et al. (2017) fed moldy feed naturally containing 56 µg OTA and 136 µg AFB1 per kg to layer hens and saw a deterioration of feather quality with increasing feeding time. Qubih (2017) noticed ruffled feathers when feeding a diet naturally contaminated with 800 ppb of OTA and 100 ppb of AFB1.

4.   Scirpenol mycotoxins

Parkhurst et al. (1992) examined the effects of different scirpenol mycotoxins. After feeding graded levels of fusarium mycotoxins to broiler chicks until three weeks of age, they discovered that the impact of scirpenols stretched across the entire feathered body parts and that the degree of feather alteration is dose-dependent. The main alteration was a frayed or even missing web on the medial side of the outer end of the feather due to poor development of the barbs, barbules, and barbicels, and the tip of the feathers became square instead of rounded—the thinner and weaker shafts of the feathers inclined to show an accentuated medial curve.

Parkhurst et al. (1992)

Figure 1: Feathering affected by scirpenol mycotoxins

In their trial, Parkhurst and Hamilton realized that 15-monoacetoxyscirpenol (15-MAS) caused the most severe alterations of feathers, and they determined a minimum effective dose (MED) of 0.5 µg/g diet. The MEDs for 4,15-diacetoxyscirpenol (4,15-DAS) and 3,4,15-triacetoxyscirpenol (TAS) were higher, 2 µg/g and > 8 µg/g, respectively.

How can we enable adequate feathering in poultry?

Adequate feathering of poultry is necessary for the animal’s health and welfare and to ensure fertility and productivity. The occurrence of mycotoxins in the feed – and the probability is high! – can cause poor feathering or the development of malformed feathers.

To best equip broilers, layers, and breeders, their feed must contain all nutrients essential for healthy growth and appropriate feathering. As the risk of contamination of the feed materials is very high (see EW Nutrition’s mycotoxin report 2023), it is of crucial importance to have an efficient mycotoxin risk management in place, which includes sampling, analysis of samples, and the use of mycotoxin binders. EW Nutrition offers MasterRisk, an online tool where farmers and feed millers can feed the results of their feed analysis concerning mycotoxins and get a risk management recommendation.

In the next part of the series, we will report on beak lesions and skin paleness, two other external signs of mycotoxin contamination.

References:

Abidin, Zain ul, Muhammad Zargham Khan, Aisha Khatoon, Muhammad Kashif Saleemi, and Ahrar Khan. “Protective Effects Ofl-Carnitine upon Toxicopathological Alterations Induced by Ochratoxin A in White Leghorn Cockerels.” Toxin Reviews 35, no. 3–4 (August 22, 2016): 157–64. https://doi.org/10.1080/15569543.2016.1219374.

Emous, R. A., and M. M. Krimpen. “Effects of Nutritional Interventions on Feathering of Poultry – a Review.” Poultry Feathers and Skin: The Poultry Integument in Health and Welfare, 2019, 133–50. https://doi.org/10.1079/9781786395115.0133.

Fisher, Colin. “Feathering in Broiler Breeder Females – Aviagen.” https://aviagen.com/, 2016. http://en.aviagen.com/assets/Tech_Center/Broiler_Breeder_Tech_Articles/English/Feathering-in-Broiler-Breeeder-Females-EN-2016.pdf.

Gu, Wang, Qiang Bao, Kaiqi Weng, Jinlu Liu, Shuwen Luo, Jianzhou Chen, Zheng Li, et al. “Effects of T-2 Toxin on Growth Performance, Feather Quality, Tibia Development and Blood Parameters in Yangzhou Goslings.” Poultry Science 102, no. 2 (February 2023): 102382. https://doi.org/10.1016/j.psj.2022.102382.

Hameed, Muhammad  Raza, Muhammad Khan, Ahrar Khan, and Ijaz Javed. “Ochratoxin Induced Pathological Alterations in Broiler Chicks: Effect of Dose and Duration.” Pakistan Veterinary Journal Pakistan Veterinary Journal 8318, no. 2 (December 2012): 2074–7764.

Hassan, Zahoor-Ul, M. Zargham Khan, Ahrar Khan, and Ijaz Javed. “Pathological Responses of White Leghorn Breeder Hens Kept on Ochratoxin A Contaminated Feed.” Pakistan Veterinary Journal 30, no. 2 (2010): 118–23.

Hoerr, F. J., W. W. Carlton, and B. Yagen. “Mycotoxicosis Caused by a Single Dose of T-2 Toxin or Diacetoxyscirpenol in Broiler Chickens.” Veterinary Pathology 18, no. 5 (September 1981): 652–64. https://doi.org/10.1177/030098588101800510.

Hoerr, F.J., W.W. Carlton, B. Yagen, and A.Z. Joffe. “Mycotoxicosis Produced in Broiler Chickens by Multiple Doses of Either T‐2 Toxin or Diacetoxyscirpenol.” Avian Pathology 11, no. 3 (January 1982): 369–83. https://doi.org/10.1080/03079458208436112.

Khan, Ahrar, Muhammad Mustjab Aalim, M. Zargham Khan, M. Kashif Saleemi, Cheng He, M. Noman Naseem, and Aisha Khatoon. “Does Distillery Yeast Sludge Ameliorate Moldy Feed Toxic Effects in White Leghorn Hens?” Toxin Reviews, January 25, 2017, 1–8. https://doi.org/10.1080/15569543.2017.1278707.

Khan, Shahzad Akbar, Eiko N. Itano, Anum Urooj, and Kashif Awan. “Ochratoxin-a Induced Pathological Changes in Broiler Chicks.” Pure and Applied Biology 12, no. 4 (December 10, 2023): 1608–16. https://doi.org/10.19045/bspab.2023.120162.

Leeson, S., and T. Walsh. “Feathering in Commercial Poultry II. Factors Influencing Feather Growth and Feather Loss.” World’s Poultry Science Journal 60, no. 1 (March 1, 2004): 52–63. https://doi.org/10.1079/wps20045.

Leeson, Steve. “Effects of Nutrition on Feathering.” Poultry World, May 22, 2021. https://www.poultryworld.net/specials/effects-of-nutrition-on-feathering/.

Leeson, Steven, Gonzalo J. Diaz Gonzalez, and John D. Summers. Poultry metabolic disorders and Mycotoxins. Guelph, Ontario, Canada: University Books, 1995.

Manafi, M., N. Pirany, M. Noor Ali, M. Hedayati, S. Khalaji, and M. Yari. “Experimental Pathology of T-2 Toxicosis and Mycoplasma Infection on Performance and Hepatic Functions of Broiler Chickens.” Poultry Science 94, no. 7 (July 2015): 1483–92. https://doi.org/10.3382/ps/pev115.

Muhammad, Ishfaq, Xiaoqi Sun, He Wang, Wei Li, Xinghe Wang, Ping Cheng, Sihong Li, Xiuying Zhang, and Sattar Hamid. “Curcumin Successfully Inhibited the Computationally Identified CYP2A6 Enzyme-Mediated Bioactivation of Aflatoxin B1 in Arbor Acres Broiler.” Frontiers in Pharmacology 8 (March 21, 2017). https://doi.org/10.3389/fphar.2017.00143.

Nguansangiam, Sudarat, Subhkij Angsubhakorn, Sutatip Bhamarapravati, and Apichart Suksamrarn. The Southeast Asian J of Tropical Medicine 34, no. 4 (2004): 899–905.

Parkhurst, Carmen R., Pat B. HamiltonON, and Adedamola A. AdemoyeroERO. “Abnormal Feathering of Chicks Caused by Scirpenol Mycotoxins Differing in Degree of Acetylation.” Poultry Science 71, no. 5 (May 1992): 833–37. https://doi.org/10.3382/ps.0710833.

Qubih, T. S. “Relationship between Mycotoxicosis and Calcium during Preproduction Period in Layers.” Iraqi Journal of Veterinary Sciences 26, no. 1 (June 28, 2012): 11–14. https://doi.org/10.33899/ijvs.2012.46888.

Saleemi, M. Kashif, Kamran Ashraf, S. Tehseen Gul, M. Noman Naseem, M. Sohail Sajid, Mashkoor Mohsin, Cheng He, Muhammad Zubair, and Ahrar Khan. “Toxicopathological Effects of Feeding Aflatoxins B1 in Broilers and Its Amelioration with Indigenous Mycotoxin Binder.” Ecotoxicology and Environmental Safety 187 (January 2020): 109712. https://doi.org/10.1016/j.ecoenv.2019.109712.

Wyatt, R.D., P.B. Hamilton, and H.R. Burmeister. “Altered Feathering of Chicks Caused by T-2 Toxin.” Poultry Science 54, no. 4 (July 1975): 1042–45. https://doi.org/10.3382/ps.0541042.

Zafar, Roheena, Farhat Ali Khan, and Muhammad Zahoor. “In Vivo Amelioration of Aflatoxin B1 in Broiler Chicks by Magnetic Carbon Nanocomposite.” Pesquisa Veterinária Brasileira 37, no. 11 (November 2017): 1213–19. https://doi.org/10.1590/s0100-736×2017001100005.

By Dr. Ajay Awati, Director of Enzymes, EW Nutrition

The use of by-products and high-fiber ingredients in feed formulations has increased in swine operations.  Driven by both economic and sustainability goals, this shift has emphasized the importance of understanding the role of dietary fibers and carbohydrases in swine nutrition and health (Petry & Patience, 2020). These feeds rich in fiber are generally considered to have low nutritional value due to the lower digestive energy or amino acid levels when compared to concentrated feeds with high starch or proteins (Woyengo et al., 2014).

Dietary fiber is vital in pig nutrition, necessitating a baseline inclusion to support regular digestive tract functions (Wenk, 2001). Incorporating fiber into the diets of monogastric animals raises concerns due to its correlation with reduced nutrient utilization and diminished net energy levels (Noblet; Le Goof, 2001). High-fiber diets can present challenges for inclusion in monogastric animals’ feeds, especially young animals, due to their bulky nature and restricted ability to ferment fiber, impacting nutrient uptake based on fiber type, the age of the pig, and diet composition (Bach Knudsen et al., 2012).

Moreover, the apparent ileal digestibility (AID) of nutrients is adversely affected by dietary fiber, attributed to the small intestine’s deficiency in endogenous enzymes necessary for breaking down these bonds (Bach Knudsen et al., 2012).

This article aims to demonstrate how enzymatic degradation of arabinoxylans, particularly through xylanase enzymes, can mitigate anti-nutritional effects and enhance the nutritional value of high-fiber swine diets, thereby improving animal health and performance.

Into the World of Arabinoxylans

In plants classified as monocotyledonous, such as cereals, the main non-starch polysaccharides (NSP’s) components of the cell wall are arabinoxylans, cellulose and β-glucan (Bach Knudsen, 1997). Arabinoxylans represent a complex group of dietary fibers with significant implications for swine nutrition and health. Their structural heterogeneity can influence physicochemical properties, biological activities, and affect pigs’ gut microbiota and immune system. Present in both soluble and insoluble forms, it consists of a backbone of xylose residues with arabinose side chains, playing a crucial role in the nutritional dynamics within swine diets (Mudgil & Barak, 2013).

The fermentability of corn-based dietary fiber is limited by its insoluble fraction and complex branched structure; impacting the digesta transit rate and reducing the digestibility of nutrients (Gutierrez et al., 2013). Supplementing exogenous carbohydrases offers a viable approach to enhance the utilization of fiber that is otherwise difficult to ferment, potentially amplifying its positive effects.

Xylanase’s Impact on Fiber and Gut Health

Non-digestible carbohydrates may be fermented by microbial populations along the gastrointestinal tract to synthesize short-chain fatty acids that may be absorbed and metabolized by the pig. Such indigestible carbohydrates consist of specific disaccharides, oligosaccharides, resistant starches, and non-starch polysaccharides. The presence and composition of these indigestible carbohydrates in pig diets vary based on the types of feed ingredients incorporated into their meals (Navarro et al., 2019). Xylanase works on the hydrolysis of the arabinoxylan fraction of NSPs. The NSPs present in the walls of plant cells encapsulate nutrients, making them unavailable for the action of the animal’s own digestive enzymes. Moreover, NSPs exhibit a high affinity for water within the gastrointestinal lumen, leading to elevated digesta viscosity. This increased viscosity reduces gastrointestinal motility, facilitating an environment conducive to the proliferation of pathogenic microflora (Choct, 1998).  The advantageous outcomes of enzyme supplementation arise from the enzymatic disruption of intact cellular membranes, leading to the release of sequestered nutrients, or are a consequence of modifying the physicochemical properties of non-starch polysaccharides, due to changes in viscosity and water-holding capacity and/or changes in the composition and content of bacteria in the intestine (Bedford, M. R., & Classen, 1992).

Arabinoxylans in Cereal Grains and Their By-products

Factors such as genetics, climate, maturity stage, fertilizer use, and post-harvest storage time influence the proportion of total cell wall polysaccharides in cereal grains. These factors vary across production systems and countries, depending on the availability of feed resources (Paloheimo et al., 2010).

Cereal grains and their by-products, including wheat bran, corn distillers dried grains with solubles (DDGS), and rice husks, serve as significant sources of arabinoxylans. Their incorporation into swine diets is growing due to economic advantages.

The ethanol industry’s growth has increased the availability of distillery by-products. Brazil alone generates an estimated 366 million tons of DDGS annually (USDA, 2017). Among these by-products, distiller-dried grains are prevalent, especially in the U.S. pork industry as feed ingredients.

Corn, wheat, and barley, as staple ingredients in swine feed, exhibit significant variations in their NSP and arabinoxylans content. In grain form, corn contains 4.7% AX with a soluble component of 0.5%, while wheat has a higher arabinoxylans content at 7.3% with 1.8% being soluble. Barley stands out with the highest arabinoxylans content at 8.4%, of which 1.2% is soluble, reflecting its rich fiber composition. The processing into flour results in a reduction of arabinoxylans content across all three cereals, highlighting the impact of processing on dietary fiber availability (Knudsen, 2014).

Rice distillers’ by-product is recognized as a valuable protein source, boasting high crude protein levels. Nonetheless, its high fiber content can restrict usage (Huang et al., 2017). Wheat bran is particularly rich in arabinoxylans, enhancing its dietary fiber content. DDGS also contain significant amounts of both soluble and insoluble arabinoxylans, resulting from the corn kernel’s residual non-starch polysaccharides (Agyekum & Nyachoti, 2017).

It is essential to understand the specific levels of arabinoxylans in these components to create balanced diets that optimize nutritional benefits while minimizing potential anti-nutritional effects.

Addressing Arabinoxylan Degradation

Xylanases target specific substrates, necessitating the presence of arabinoxylans for their effective action. The complex structure of arabinoxylans makes them resistant to degradation by the swine’s endogenous enzymes, presenting a dual challenge: how to harness the beneficial effects of soluble arabinoxylans while mitigating the negative impacts of their insoluble counterparts.

These enzymes specifically cleave the 1,4-β-D-xylosidic bonds in arabinoxylans, randomly targeting xylose linkages within the xylan structure. Each enzyme type has a unique pattern of degradation (Collins et al., 2005) and GH 10 xylanases specialize in breaking down arabinoxylans with high arabinose substitution into smaller oligosaccharides. These oligosaccharides are valuable for fermentation, serving as energy sources or prebiotics.

Also, this group of enzymes action not only reduces gut viscosity but can lead to enhanced feed efficiency, growth performance, and overall health of swine by improving the digestibility of fibrous components in feed (Lærke et al., 2015). GH 10 xylanases often have optimal activity at pH levels found in the animal gut, and their thermal stability ensures they retain activity under feed processing temperatures.  Lei et al. (2016) highlighted the efficacy of xylanase in improving nutrient digestibility and overall feed efficiency. By targeting the arabinoxylans present in swine diets, xylanase enzymes facilitate a more efficient conversion of feed into energy, contributing to improved growth rates and performance metrics.

As detailed by Tiwari, Singh, & Jha (2019), arabinoxylans undergo fermentation in the gut, leading to the production of short-chain fatty acids (SCFAs) that beneficially alter the gut microbial ecology. The application of GH 10 xylanases has been highlighted for its potential to significantly enhance the degradation of arabinoxylans, thereby improving the fermentation process and increasing the yield of SCFAs. This enzymatic breakdown facilitates more efficient nutrient absorption and overall better gastrointestinal health, directly influencing swine growth and performance positively.

A study reveals that xylanase supplementation significantly reduces mortality rates in pigs in a dose-dependent manner. With mortality rates dropping from 4.16% in the control group to as low as 2.25% with the highest xylanase dosage, the results highlight xylanase’s potential to improve gut health and increase survival rates. This suggests a promising approach for boosting pig well-being and reducing the reliance on enteric antibiotics, marking a significant stride in sustainable animal nutrition practices.(Zier-Rush et al., 2016).

The research conducted by Petry et al. (2020) demonstrated that xylanase increased the digestibility of non-starch polysaccharides, particularly arabinoxylan, in diets high in insoluble corn fiber. This improvement in nutrient absorption highlights xylanase’s role in optimizing the use of high-fiber ingredients in swine diets, thereby enhancing animal health and performance. Due to its cost-effectiveness and nutrient profile, xylanase supplementation enhances the nutritional value of DDG in swine diets.

The strategic implementation of xylanase in swine diets represents a promising approach to the challenges posed by high-fiber feed ingredients. By improving the digestibility of arabinoxylans and other complex carbohydrates, xylanase supplementation can mitigate the anti-nutritional effects of insoluble fibers, enhance feed efficiency, and support optimal growth and health outcomes in swine.

Enhancing Swine Productivity with Enzyme Solutions

With the growing incorporation of co-products in swine feed, there arises a crucial need to transform the high fiber content into a beneficial asset for the animals. The strategic incorporation of enzyme solutions, particularly xylanase enzymes, into swine feed formulations emerges as a scientifically supported approach to significantly enhance the digestibility of high-fiber diets. This method effectively addresses the nutritional intricacies posed by arabinoxylans, facilitating improved feed utilization. Moreover, the action of xylanase enzymes extends beyond enhancement of nutrient absorption; it plays a pivotal role in promoting the health and performance of swine. Such targeted nutritional strategies are vital in the context of swine production systems, highlighting the necessity of integrating these enzymatic solutions to achieve optimal animal health, growth, and productivity.

References:

1. Agyekum, K. A., & Nyachoti, C. M. (2017). Nutritional and metabolic consequences of feeding high-fiber diets to swine: A review. Engineering, 3(5), 716-725. https://doi.org/10.1016/J.ENG.2017.03.010
2. Bach Knudsen, K. E. (1997). Carbohydrate and lignin contents of plant materials used in animal feeding. Animal Feed Science and Technology, 67, 319-338.
3. Bach Knudsen, K. E., Hedemann, M. S., & Laerke, H. N. (2012). The role of carbohydrates in intestinal health of pigs. Animal Feed Science and Technology, 173, 41–53.
4. Bedford, M. R., & Classen, H. L. (1992). Reduction of intestinal viscosity through manipulation of dietary rye and pentosanase concentration is effected through changes in the carbohydrate composition of the intestinal aqueous phase and results in improved growth rate and food conversion efficiency of broiler chicks. The Journal of Nutrition, 122, 560-569.
5. Choct, M. (1998). The effect of different xylanases on carbohydrate digestion and viscosity along the intestinal tract in broilers. Australian Poultry Science Symposium, 10.
6. Collins, T., Gerday, C., & Feller, G. (2005). Xylanases, xylanase families and extremophilic xylanases. FEMS Microbiology Reviews, 29(1), 3–23. https://doi.org/10.1016/j.femsre.2004.06.005
7. Gutierrez, N. A., Kerr, B. J., & Patience, J. F. (2013). Effect of insoluble-low fermentable fiber from corn-ethanol distillation origin on energy, fiber, and amino acid digestibility, hindgut degradability of fiber, and growth performance of pigs. Journal of Animal Science, 91, 5314–5325. https://doi.org/10.2527/jas.2013-6328
8. Huang, Y. F., Gao, X. L., Nan, Z. B., & Zhang, Z. X. (2017). Potential value of the common vetch (Vicia sativa L.) as an animal feedstuff: A review. Journal of Animal Physiology and Animal Nutrition, 101, 807-823. https://doi.org/10.1111/jpn.12617
9. Lærke, H. N., Arent, S., Dalsgaard, S., & Bach Knudsen, K. E. (2015). Effect of xylanases on ileal viscosity, intestinal fiber modification, and apparent ileal fiber and nutrient digestibility of rye and wheat in growing pigs. Journal of Animal Science, 93(9), 4323-4335.
10. Lei, Z., Shao, Y., Yin, X., Yin, D., Guo, Y., & Yuan, J. (2016). Combination of xylanase and debranching enzymes specific to wheat arabinoxylan improve the growth performance and gut health of broilers. Journal of Agricultural and Food Chemistry, 64(24), 4932-4942.
11. Mudgil, D., & Barak, S. (2013). Composition, properties and health benefits of indigestible carbohydrate polymers as dietary fiber: a review. International Journal of Biological Macromolecules, 61, 1-6. https://doi.org/10.1016/j.ijbiomac.2013.06.044
12. Navarro, D. M. D. L., Abelilla, J. J., & Stein, H. H. (2019). Structures and characteristics of carbohydrates in diets fed to pigs: a review. Journal of Animal Science and Biotechnology, 10, 39. https://doi.org/10.1186/s40104-019-0345-6
13. Noblet, J., & Le Goff, G. I. (2001). Effect of dietary fibre on the energy value of feeds for pigs. Animal Feed Science and Technology, 90, 35-52.
14. Paloheimo, M., Piironen, J., & Vehmaanperä, J. (2010). Xylanases and cellulases as feed additives. In M. Bedford & G. Partridge (Eds.), Enzymes in farm animal nutrition (2nd ed., pp. 12-53). CABI Publishing. https://doi.org/10.1079/9781845936747.0012
15. Petry, A., Huntley, N., Bedford, M., Zijlstra, R. T., & Patience, J. (2020). Supplementing xylanase increased the digestibility of non-starch polysaccharides, particularly arabinoxylan, in diets high in insoluble corn fiber fed to swine with a 36-d dietary adaptation period. Journal of Animal Science, 98(52-52).
16. Petry, A. L., & Patience, J. F. (2020). Xylanase supplementation in corn-based swine diets: a review with emphasis on potential mechanisms of action. Journal of Animal Science, 98(11), skaa318. https://doi.org/10.1093/jas/skaa318
17. Tiwari, U., Singh, A., & Jha, R. (2019). Fermentation characteristics of resistant starch, arabinoxylan, and β-glucan and their effects on the gut microbial ecology of pigs: A review. Animal Nutrition, 5, 217-226.
18. United States Department of Agriculture (USDA). (2017). Biofuel Annual. Economic Research Service. https://www.fas.usda.gov/commodities/biofuels
19. Wenk, C. (2001). The role of dietary fibre in the digestive physiology of the pig. Animal Feed Science and Technology, 90, 21-33.
20. Woyengo, T. A., Beltranena, E., & Zijlstra, R. T. (2014). Nonruminant nutrition symposium: controlling feed cost by including alternative ingredients into pig diets: a review. Journal of Animal Science, 92(4), 1293-1305.
21. Zier-Rush, C. E., Groom, C., Tillman, M., Remus, J., & Boyd, R. D. (2016). The feed enzyme xylanase improves finish pig viability and carcass feed efficiency. Journal of Animal Science, 94(suppl_2), 115. https://doi.org/10.2527/msasas2016-244

By Dr. Ajay Awati, Global Director Enzymes, EW Nutrition

In recent years, the scientific understanding of xylanase inhibitors (XIs) and their impact on animal nutrition has grown significantly. Xylanase, a crucial enzyme used to enhance nutrient availability in feed, can face challenges from XIs present in cereal grains. This article explores the evolution of plant protection mechanisms, the economic impact of XIs, and the development of a novel xylanase, Axxess XY, resistant to these inhibitors.

Xylanase inhibitors – an evolutionary protection mechanism of plants

Xylanase inhibitors (XI) are a classic example of the evolutionary development of protection mechanisms by cereal plants against pathogens. Microorganisms, such as fungal pathogens, involve the degradation of xylan as one of the mechanisms in pathogenesis (Choquer et al., 2007). There are also other mechanisms by which microorganism-produced xylanases affect plants.

To protect themselves, plants evolved xylanase inhibitors to prevent the activities of xylanases. XIs are plant cell wall proteins broadly distributed in monocots. There are three classes of XIs with different structures and inhibition specificities (Tundo et al., 2022):
1. Triticum aestivum xylanase inhibitors (TAXI)
2. Xylanase inhibitor proteins (XIP), and
3. Thaumatin-like xylanase inhibitors (TLXI).

Xylanase inhibitors have an economic impact

In animal nutrition, xylanases are widely used in diets containing cereal grains and other plant materials to achieve a higher availability of nutrients. The inhibitory activity of XIs prevents this positive effect of the enzymes and, therefore, makes them economically relevant. Studies have reported that higher levels of XIs negatively impact broiler performance. For example, in one of the studies, broilers fed with grains of a cultivar with high inhibitory activity showed a 7% lower weight on day 14 than broilers fed with grains of a cultivar with less inhibitory activity (Madesen et al., 2018). Another study by Ponte et al. (2004) also concluded that durum wheat xylanase inhibitors reduced the activity of exogenous xylanase added to the broiler diets.

Xylanase inhibitors can withstand high temperatures

Even though XIs can impact the performance of exogenous xylanase in different ways, only minor attention was paid to the reduction of xylanase’s susceptibility to xylanase inhibitors during the xylanase development in the last decades. Firstly, the issue was ignored mainly through the assumption that XIs are denatured or destroyed during pelleting processes. However, Smeets et al. (2014) showed that XIs could sustain significant temperature challenges. They demonstrated that after exposing wheat to pelleting temperatures of 80°C, 85°C, 92°C, and 95°C, the recovery of inhibitory activity was still 99%, 100%, 75%, and 54%, respectively. Furthermore, other studies also confirmed that conditioning feed at 70-90°C for 30 sec followed by pelleting had little effect on the XI activity in the tested feed, showing that xylanase inhibitors are very likely present in most xylanase-supplemented feeds fed to animals.

Do we only have the problem of xylanase inhibitors in wheat?

No. After first reports of the presence of xylanase inhibitors in wheat by Debyser et al. (1997, 1999), XIs were also found in other cereal grains (corn, rice, and sorghum, etc.), and their involvement in xylanase inhibition and plant defense has been established by several reports (Tundo et al., 2022).

In most of the countries outside Europe, exogenous xylanase is used not only in wheat but also in corn-based diets. Besides broiler feeds, also other animal feeds, such as layer or swine feed being part of more mixed-grain diets, are susceptible to the inhibitory activity of XIs. Nowadays, the situation is getting worse with all the raw material prices increasing and nutritionists tending to use other feed ingredients and locally produced cereals. They need a xylanase which is resistant to xylanase inhibitors.

Xylanases’ resistance to XIs is crucial – Axxess XY shows it

To prevent xylanases from losing their effect due to the presence of xylanase inhibitors, the resistance of new-generation xylanases to these substances is paramount in the development process, including enzyme discovery and engineering.

In the past 25 years, scientists have learned much about XI-encoding genes and discovered how xylanase inhibitors can block microbial xylanases. Additionally, there has been a significant increase in understanding the structural aspects of the interaction between xylanases and XIs, mainly how xylanase inhibitors interact with specific xylanases from fungi or bacteria and those in the GH10 or GH11 family. With such understanding, a new generation xylanase, Axxess XY, was developed. Besides showing the essential characteristics of intrinsic thermostability and versatile activity on both soluble and insoluble arabinoxylan, it is resistant to xylanase inhibitors.

Axxess XY takes xylanase application in animal feeds to the next level.

Axxess XY outperforms other xylanases on the market

Recent scientific developments (Fierens, 2007; Flatman et al., 2002; Debyser, 1999; Tundo et al., 2022; Chmelova, 2019) and internal research can be summarized as follows:

Figure 1: Schematic summary of the susceptibility of different xylanase to xylanase inhibitors from three main groups.

The high resistance to xylanase inhibitors is one of the reasons that a novel xylanase with bacterial origin and from the GH-10 family was chosen to be Axxess XY. EWN innovation, together with research partners, made an interesting benchmark comparison between xylanases that are commercially sold by different global suppliers and Axxess XY. For these trials, all xylanase inhibitors from wheat were extracted. The inhibitors, together with the respective xylanase, were incubated at 40⁰C (to mimic birds’ body temperature) for 30 mins. Then, the loss of xylanase activity was calculated by analyzing remaining activity after incubation. Results are shown below in Figure 2. There were varying levels of activity loss observed in the different commercially sold xylanases. In some xylanases, the losses were alarmingly high. However, Axxess XY was not inhibited at all.

Fig. 2: Extracted total xylanase inhibitors from wheat incubated with the respective xylanase at 40°C for 30 mins. – Loss of activity after incubation with xylanase inhibitors

Conclusion:

Xylanase inhibitors are present in all cereal grains and, unfortunately, heat tolerant (up to 90⁰C, still 75% of inhibition activity was retained). Regardless of the diets used, there is a possibility that the xylanase used may come across xylanase inhibitors, resulting in a loss of activity. More importantly, this can lead to inconsistent performance.

For effective, consistent, and higher performance of NSP enzyme application, it is a must to use xylanase that is resistant to xylanase inhibitors.

Literature:

Chmelová, Daniela, Dominika Škulcová, and Miroslav Ondrejovic. “Microbial Xylanases and Their Inhibition by Specific Proteins in Cereals.” KVASNY PRUMYSL 65, no. 4 (2019). https://doi.org/10.18832/kp2019.65.127. LINK

Choquer, Mathias, Elisabeth Fournier, Caroline Kunz, Caroline Levis, Jean-Marc Pradier, Adeline Simon, and Muriel Viaud. “Botrytis CinereaVirulence Factors: New Insights into a Necrotrophic and Polyphageous Pathogen.” FEMS Microbiology Letters 277, no. 1 (2007): 1–10. https://doi.org/10.1111/j.1574-6968.2007.00930.x. LINK

Debyser, W, WJ Peumans, EJM Van Damme, and JA Delcour. “Triticum Aestivum Xylanase Inhibitor (Taxi), a New Class of Enzyme Inhibitor Affecting Breadmaking Performance.” Journal of Cereal Science 30, no. 1 (1999): 39–43. https://doi.org/10.1006/jcrs.1999.0272. LINK

Singapore – March 12, 2024 – EW Nutrition, a leading innovator in the animal nutrition industry, officially launched its newest product, Axxess XY, in VICTAM 2024, at the BITEC Exhibition Center in Bangkok.

Axxess XY is an intrinsically thermostable xylanase that breaks down both the soluble and insoluble fiber fraction from feed ingredients such as corn, wheat, grain by-products and oilseed cakes. It releases nutrients trapped in cell wall fractions and improves the gut environment by reducing viscosity. The newly launched product thus gives feed producers peace of mind when working with various feed processing conditions, as well as significant feed cost savings with flexibility in feed formulation.

“The successful launch of Axxess XY in VICTAM 2024 demonstrates our commitment to provide cutting-edge solutions to address the evolving needs of animal production and to contribute to the growth of the industry in the region.” said Ramakanta Nayak, regional director for EW Nutrition South East Asia/Pacific.

Dr. Ajay Awati, Global Director of Enzymes, EW Nutrition, expressed enthusiasm about the product launch, stating, “We are excited to have had such an amazing response to Axxess XY during and after our launch at VICTAM 2024. Axxess XY is the result of EW Nutrition R&D team’s hard work and dedication to pushing the boundaries of enzymes technology in animal nutrition.”

Axxess XY is touted as the most advanced xylanase yet, making EW Nutrition an important player in the enzyme market.

About EW Nutrition 

EW Nutrition offers animal nutrition solutions to the feed industry. The company’s focus is on gut health, supported by other product lines. EW Nutrition researches, develops, produces, sells, and services most of the products it commercializes. In 50 countries, key accounts are served directly by EW Nutrition’s own personnel.  

For more information, please visit https://ew-nutrition.com. 

Contact: 

info@ew-nutrition.com

VISBEK, 5 March 2024 – EW Nutrition, a global provider of animal nutrition solutions, announced today that it has acquired the BIOMIN BIOSTABIL product line from dsm-firmenich. The deal gives EW Nutrition ownership over an established and successful line of silage inoculants.

“The agreement we have concluded gives us a solid foothold in a sector where we are currently developing a more substantial presence” says Jan Vanbrabant, CEO of EW Nutrition. “EW Nutrition continues to expand strategically, enriching its portfolio with market-leading solutions, developed in-house or through acquisitions. The Biomin Biostabil line joins an innovative portfolio that has been growing tremendously in the last three years with the launch of Ventar D and Pretect D, our Feed Quality and Pigment lines acquired in 2021, and yet another momentous global launch coming up shortly.” This solid, well-proven line of silage inoculants, says Vanbrabant, will be an important addition to customers of EW Nutrition’s On-Farm Solutions business around the world.

The transaction was closed on March 1, 2024. Under the services agreement concluded, all customers will be actively supported over the next months, while the asset, brand, and go-to-market will be transitioned to EW Nutrition in the coming period.

The financial details of the sale remain confidential.

By Technical Team EW Nutrition

As the planet’s climate experiences changes, new patterns affect the microbial communities colonizing crops. Recently, several areas of the planet have experienced extreme temperatures, drought, changes in the humid/dry cycles, and an increase in atmospheric carbon dioxide (1,2). As a response, the fungi affecting the crops have shifted their geographical distribution, and with this, the pattern of mycotoxin occurrence also changed. For instance, in Europe, we are looking at higher frequencies and levels of Aflatoxins (AF), Ochratoxins (OT), and Fumonisins (FUM) than ten or even five years ago (2-4).

This affects animal production, as mycotoxin challenges show increased frequency, quantity, and variety. Mainly long-living animals, such as laying hens and breeders, can have a higher risk. Moreover, mycotoxins can also be carried over to the eggs, potentially risking human health in the case of layers (table eggs) and in the case of breeder hens, hatchery performance and day-old chick (DOC) quality.

Laying hens and breeders: carryover of mycotoxins into eggs

Most mycotoxins are absorbed in the proximal part of the gastrointestinal tract (Table 1). This absorption can be high, as in the case of aflatoxins (~90%), but also very limited, as in the case of fumonisins (<1%), with a significant portion of unabsorbed toxins remaining within the lumen of the gastrointestinal tract (5).

Once mycotoxins are ingested, detoxification and excretion processes are started by the body, and at the same time, organ damage ensues. The detoxification of mycotoxins is mainly carried out by the liver (6), and their accumulation happens primarily in the liver and kidneys. However, accumulation in other tissues, such as the reproductive organs and muscles, has also been found (7-9). The detoxification process’ objective is the final excretion of the toxins, which occurs through urine, feces, and bile; often, the toxins can also reach the eggs (7-20).

Table 1: mycotoxin absorption rates for poultry and their carry-over rate into eggs

(Adapted from 5, 7-17, 19-21)

Table 1 shows carry-over rates of mycotoxins into eggs, resulting from diverse studies (7-10, 14, 16, 19). However, the same studies indicate that results can vary broadly due to different factors, as reviewed by Völkel and collaborators (26). This variability is related to the amount and source of contamination, way of application, period, and the possible co-occurrence of various mycotoxins or several metabolites. Other factors to consider are animal-related, such as species, breed, sex, age group, production level, and health status. Environmental and management factors can play a role in carry-over rates, and finally, detection limits and analytical procedures also influence these results. In summary, highly varying carry-over has been demonstrated, and the risk needs to be considered when animals are exposed.

Mycotoxins in breeder’s feed impact hatchery performance and day-old chick quality

When hens are exposed to mycotoxins, their effects on the intestine, liver, and kidney decrease egg production and quality (10, 14, 27), and, in the case of breeders, consequently, affect hatchery performance, DOC production, and DOC quality (28-30). The main effects of mycotoxins, when we speak about DOC production, are exerted in the gastrointestinal tract, the liver, and the kidneys, affecting embryos and young chicks:

• Intestine and kidneys: Mycotoxins harm the intestinal epithelium and have nephrotoxic effects, affecting calcium and vitamin D3 absorption and metabolism, necessary for eggshell quality (31). Thin and fragile shells can increase embryonic mortality, lower embryonic weight gain, and hinder hatchability (32).
• Liver: The liver plays a central role in egg production as it is responsible for vitamin D3 metabolism, the production of nutrient transporters, and the synthesis of the lipids that make up the yolk. Thus, when liver function is impaired, the internal and external quality of the egg declines, which affects DOC production (31-34).
• Embryo and young chicks: Studies (33-38) have found how mycotoxins affect the embryos. In general, there are two possibilities: the direct one, when the mycotoxin is transferred into the egg, and the indirect one, when the mycotoxin impacts egg quality and, therefore, leads to disease or death of the embryo. The result is a higher embryonic mortality or lower DOC quality. These, among others, result from the lower transfer of antioxidants and antibodies from the hen, low viability of the chick’s immune cells, and higher bacterial contamination. A lower relative weight of the bursa of Fabricio and the thymus is often found.

Qreshi’s team (29) studied the effects on the progeny of broiler breeders consuming feed highly contaminated with AFB1, finding suppression in antibody production and macrophage function in chicks after ten days. Similar results were found by other researchers (36, 37) evaluating the effects of AF and OTA as single and combined contamination. When both mycotoxins are present in the feed, the effect on hatchability and DOC quality are synergistic.

Due to mycotoxin contamination, the reproduction and immune response are impaired, resulting in decreased DOC production and increased early chick mortality, as they are more susceptible to bacterial and viral infections.

Mycotoxins impair table egg production and quality

Studies (22-24) have found mycotoxin contamination in commercial table eggs. A meta-analysis of mycotoxins’ concentration based on 11 published papers was completed recently (22): counting with data from 9509 samples, the meta-analysis reveals an overall presence of mycotoxins in 30% of the samples, being Beauvericin in the first place, followed by DON as well as AF and OTA in third and fourth place, respectively. The risk for humans depends on the intake of contaminated foods in terms of amount and frequency (25), and so far, it has not been estimated in most parts of the world.

Natural contamination in laying hens: a case report

Giancarlo Bozzo’s team (39) reported and published a veterinary case regarding natural mycotoxin contamination in commercial egg production: up to week 47 of age, production parameters were on top of the genetic standards. However, a drop in egg production started at around week 47, and at week 50, egg production was only 68% (figure 1).

Figure 1: production of laying hens fed naturally contaminated feed with AFB1 and OTA

The house with the reduced performance received feed with linseed. In other houses of the same complex, which did not include linseed in the feed, production was unaffected. Therefore, this raw material was considered a possible cause of the issue. Linseed was removed from the formula, and three weeks after (53 weeks of age), egg production was at 84%. Afterward, linseed got back into the formulation, and the laying rate dropped again to 70% (week 56), this time accompanied by a significant increase in mortality.

Samples were collected at week 56, and AFB1 and OTA were detected in feed and the kidneys and livers of the hens consuming it (table 2). While the levels in the feed were not considered high risk, evidence from necropsy and histopathology suggested either a higher or a prolonged exposure; a synergistic effect of both mycotoxins on hen’s health and productivity can be inferred.

Table 2: mycotoxin analysis results for feed and organs

The liver and kidneys were enlarged and showed signs of damage. Furthermore, urate crystals in the peritoneum and the abdominal air sac were observed, indicating renal failure. This limited the excretion of both toxins in the urine, increasing their half-life in the organism and enhancing the effects in target organs, contributing to the synergistic effect observed.

After using mycotoxin-free certified linseed, the problem receded. Though this is the best option to keep animals healthy and productive, it may not be practical in the long term due to the ubiquitous nature of the toxins and the cost and availability constraints of feed raw materials. Moreover, the mycotoxin levels present in the feed were relatively low and fell under recommended guidelines. For these reasons, in-feed toxin mitigation solutions must also be considered to reduce exposure for production animals.

In-feed intervention mitigates the effects of intermittent exposure to multiple mycotoxins

EW Nutrition conducted a study with Hy-Line W-36 layer-breeders intercalating three 10-day cycles of feed with 100ppb AFB1 + 100ppb OTA, with two 21-day cycles of non-challenged feed. An in-feed intervention (Solis Max 2.0, displayed as IFI) containing bentonite, yeast cell wall components, and a mixture of phytogenic components mitigated all effects.

Table 3: experimental groups and mycotoxin challenge

Trial design:

A total of 576 hens (18 replicates per diet, 8 hens each) and 58 roosters were randomly assigned to four diets at 28 weeks of age, as shown in Table 3. The 72-day experimental period included alternating 10-day challenge and 21-day non-challenge intervals (Figure 2). During the challenge intervals, the breeders in T-3 and T-4 were fed the mycotoxin-contaminated feed with and without the IFI.

Figure 2: trial timeline showing challenge and non-challenge intervals and days of data collection and sampling.

Mitigated effects on egg production and egg quality

The challenge decreased overall egg production (Figure 3), egg mass, and shell thickness (Table 4). The first challenge interval did not affect production, but days later, from the first non-challenge period, all parameters were lower for the challenged group.

Different letters indicate significant differences (p<0.05). Statistical tendencies (p<0.1) are indicated by (*).

Figure 3: Egg production of hens intermittently challenged with AFB1 and OTA, with and without in-feed Solis Max

The adverse effects on productivity and egg quality started after the first challenged feed was withdrawn and persisted through the following intervals until the end of the experiment. Similar effects in chronic mycotoxin challenges have been previously found (37, 39).

Table 4: Average egg quality parameters of hens intermittently challenged with AFB1+OTA, with and without an in-feed intervention (IFI)

Different letters indicate significant differences (p<0.05). Statistical tendencies (p<0.1) are indicated by (*).

Mitigated effects on the progeny in incubation trials

Three incubation trials were performed: after the first challenge and non-challenge interval and at the end of the trial period after the third challenge interval. A significant decrease in fertility and hatchability was observed for the challenged group in all incubation trials. As mycotoxins affect egg quality (22-24) and can be transferred to the eggs (10, 14, 27), the effects were also shown in the case of hatchability and offspring performance. Fertility was affected from the first challenge interval onwards, continuing to be low for the challenge group until the end of the trial. However, the hatchability of fertile eggs dropped after the withdrawal of the contaminated feed and showed the lowest value during the third challenge interval.

The in-feed supplementation of Solis Max 2.0 (IFI) resulted in the consistent recovery of egg production and egg quality throughout the whole experimental period, achieving the same levels of productivity as the non-challenged control.

Figure 4: Hatchery parameters of eggs from breeders intermittently challenged with AFB1 and OTA, with and without an in-feed intervention (IFI).

Results in hatch of fertile can be related to egg quality, as the thickness of the eggshell influences the egg’s moisture loss and exchange with the environment during the incubation period. Thinner eggshells lead to higher embryo mortality (31, 32). The group having the challenge with Solis Max showed the same performance as the non-challenged control regarding hatchery performance.

Day-old chick weight was not affected. However, weight gain and mortality after ten days were hindered for the chicks from breeders taking the mycotoxin-contaminated feed (Table 5).

Table 5: Average day- and 10-day-old chick parameters from hens intermittently challenged with AFB1+OTA, with and without an in-feed intervention (IFI)

Letters indicate significant differences (p<0.05). Statistical tendencies (p<0.1) indicated by (*)

At the end of the experiment, oxidative stress biomarkers were measured in the blood serum of 15 hens per treatment, showing significantly lower GPx, and SOD (figure 5) in the challenged group, which indicates a depletion of the mechanisms to fight oxidative stress (40), the hens taking the in-feed product did not show this depletion.

Figure 5: Antioxidants in blood serum, glutathione peroxidase (GPx), and superoxide dismutase (SOD) from breeders intermittently challenged with AFB1 and OTA, with and without an in-feed intervention (IFI).

Intermittent exposure to AFB1 and OTA negatively affected layer breeder productivity, egg quality, and hatchability and promoted oxidative stress in the birds. Intermittent mycotoxin challenges may affect animals even after the contamination is withdrawn. In-feed interventions showed effectiveness in mitigating these effects.

Climate changes bring new mycotoxin challenges – the right in-feed solutions can help

Today’s mycotoxin scenario shows increased frequency, quantity, and variety. Mainly long-living animals, such as laying hens and breeders, can be at more risk. Additionally, the contamination can be carried over to the eggs, potentially risking human health in the case of table eggs and hatchery performance and DOC quality in the case of breeders.

From case reports, we learn the consequences of real challenges and struggles in commercial production; from scientific trials based on possible commercial situations, we realize the advantages of interventions designed to tackle those challenges.

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