Intervention strategies to support immune competence

As mycotoxins are ubiquitous in poultry diets and symptoms are mostly unspecific, their incidence can perpetuate the use of therapeutic interventions to control the risk of infection in the flock. Photo: Trouw

As poultry producers seek to ease the use of antibiotic treatments, the relevance of feed quality and farm health becomes increasingly vital. The threats posed by mycotoxin contamination in feed ingredients, suggest considerations for assessing risk, and describe intervention strategies to mitigate the challenges faced by producers.

An effective antibiotic reduction programme is contingent upon an integrated and comprehensive approach encompassing farm biosecurity, feed quality and safety, supported by proper prophylactic health management practices. While often overlooked at the farm level, the presence of mycotoxins and other xenobiotics in poultry diets is ubiquitous. Frequently found in combination, mycotoxins are known to lessen the animal immune competence, increasing the requirement for antibiotics use to offset disease and performance impairment.

Adverse effects of mycotoxins

Mycotoxins presence has been associated with negative effects on immune competence and gut integrity. The concentration, chemical composition and synergic effects, contribute to the adverse symptoms in growing animals while more prominently in chicks, layers and breeders due to the immature immune system and longer time of exposure. At low, chronic levels, mycotoxins can affect birds’ humoral and cellular immune responses, increasing susceptibility to infectious diseases by reducing the effectiveness of health management protocols, as vaccination treatments.

At moderate to more elevated levels, Aflatoxin B1, Ochratoxin A, Fumonisins and Trichothecenes such as DON, T2, HT-2 have been shown to impair gut health, reducing nutrient absorption, cellular membrane integrity, and increasing oxidative stress and protein synthesis such as immunoglobulins. The recognised impact on enterocytes tight junction complex, triggered by inflammatory cytokines in the gastrointestinal tract, increases the passage rate of bacteria such as salmonella or coccidia into systemic circulation. As mycotoxins are ubiquitous in poultry diets and symptoms are mostly unspecific, their incidence can perpetuate the use of therapeutic interventions to control the risk of infection in the flock, promoting antibiotic resistance.

Common mycotoxins and associated threats

Aflatoxin B1: AFB1 decreases the number of circulating T-lymphocytes and splenic cell counts, reduces macrophage activity and increases the production of pro-inflammatory cytokines making the animals more predisposed to acute bacterial and fungal infections.
Ochratoxin A: Decreases the synthesis of immunoglobulins. Impairment of cell-mediated immunity is associated with decrease in circulating lymphocytes, monocytes and macrophages. Failure on acquired immunity has been shown after vaccination of immunised and neonatal animals when Ochratoxin A is present.
Trichothecenes: As T-2, HT-2 affects bone marrow cells, resulting in pancytopenia with reduced leukocyte counts, reduced blastogenic transformation of lymphocytes, and reduced response to mitogens of peripheral lymphocytes, thyme and spleen cells.
Deoxynivalenol (DON): Short-term exposure activates pro-inflammatory cytokines, while long exposure to low or moderate levels suppresses the synthesis of IgA and IgG levels.
Fumonisins: Induce the production of nitric oxide and impair lipid biosynthesis essential for gut wall integrity. Fumonisins and Trichothecenes induce cellular oxidative stress and a depletion of cellular defence mechanisms such as glutathione peroxidase. Cells with high energy demand and rapid proliferation as enterocytes and immune cells are particularly vulnerable to oxidative stress.

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Diagnostics and analytics

While a holistic approach to mycotoxin risk should be considered, mycotoxin risk management is a fundamental part of producers’ strategies to support flock health and performance. The use of on-farm diagnostic tools can help producers to more clearly assess and quantify mycotoxin presence in the feed. Trouw Nutrition’s strategy to support producers around the globe has been to further develop accessible and digitally enabled mycotoxin diagnostics, positioned at feed mills and farms. Currently over 200 NutriOpt Mycomasters have been deployed worldwide. By providing real-time analysis in over 40 validated raw materials and finished feed, this technology allows for the identification of critical control points in the feed production chain, allowing for adjustments in formulations and intervention strategies application, proactively reducing the mycotoxin risk posed to the animals.

Supporting immune modulation and farm productivity

A chronical challenge in immunity translates into birds not being able to achieve their full growth potential and to the increased veterinary costs with medication. The spare use of antibiotics may result in compromising the economic profitability of farms and dramatically reduce the value of birds in antibiotic-free systems. Being able to quantify and develop an in-depth overview of the challenge are key to selecting an effective intervention strategy. To counteract the effects of mycotoxins in immunity, Trouw Nutrition, has selected a blend of smectite based clays, glucose biopolymers and activated β-glucans to reduce the bioavailability of mycotoxins, support gut integrity and modulate the immune system (Figure 1).

Looking towards the future

Today’s poultry producers strive to meet consumers’ desire for safe and economical food production. Achieving this overriding goal and growing demand for antibiotic free systems, requires a holistic feed-farm-health approach to reduce disease incidence and support immune competence. As a research based organisation, Trouw Nutrition’s research partners in the Netherlands and around the globe, are focusing on improving feed safety, gut health, and developing nutritional solutions, by investigating how functional nutrients influence specific gene expression and the microbiome.

References available upon request.

The World Mycotoxin Forum goes to Asia!

The world leading independent mycotoxin conference – The World Mycotoxin Forum – is spreading its wings and will organise the first Asia edition in January 2020. The event will be organised by Misset International, the publisher of the international multimedia brand All About Feed, in cooperation with Bastiaanse Communication, the creator and organiser of the regular editions of the World Mycotoxin Forum. WMFmeetsASIA will be held 13-15 January 2020 in Bangkok. Registration is now open.