The impact of reducing mycotoxins in poultry feed on the natural defense against disease

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Lowering the use of antimicrobials in animal feeds, particularly as growth promoters (AGPs), and to treat disease have been defined as priorities by the Canadian Poultry Research Council. Although alternatives are sought, these too may force microbial resistance. Therefore, we propose an overall strategy to maintain health, production and efficiency without AGPs requires improvements in bio-security, management practices and nutrition, specifically to feed diets with low levels of mycotoxins. Mycotoxins are chemicals produced by fungi as a defense. Of concern are the mycotoxins associated with Fusarium Head Blight (FHB) a fungal disease in crops grown worldwide. In Canada, the incidence of FHB has been increasing and there are concerns that it is becoming more infectious and producing more types and higher levels of mycotoxins. Worldwide, CAST (2003) estimates that 25% of all cereals have some level of mycotoxins. In a recent meta-analysis (Andretta et al., 2011) of 98 papers (between 1980-2009) concluded that mycotoxins reduced broilers feed intake by 12% and weight gain by 14% compared to the respective control diets. Yegani et al. (2005) estimated that Canadian livestock and poultry producers lost $1B between 1990 and 1999. FHB also significantly impacts yield and grain quality and losses are estimated at $80M/yr to Canadian cereal producers. The animal industry responds by avoiding sources of mycotoxins and use of supplements to bind and/or detoxify the toxins that may be present. Our research group has recently installed new (first installation in NA) technology that facilitates commercial sorting of individual kernels of grain using Near Infrared Reflectance (NIR) spectroscopy. Sources of grain can be separated into three fractions based on crude protein. During an infestation, FHB reduces protein deposition in individual kernels. Preliminary data using the sorting technology has been associated with recovery of >90% of the kernels and lowering levels of mycotoxins to low or non-detectable levels. Emphasis will be made to understand the impact of mycotoxins on immune capacity or the animal's ability to respond to disease challenge or mount a good vaccine response and reduce reliance on AGPs.