Effects of tryptophan supplementation in diets containing naturally contaminated corn with aflatoxin on growth performance, carcass traits, blood biochemistry, locomotor disorders, and intestinal morphology of broiler chickens

This study was conducted to investigate the effects of dietary tryptophan supplementation on the performance and health of broilers fed a diet containing moldy corn. In a completely randomized design, 420 five-day-old male broiler chickens were allocated to three dietary treatments for 23 days, each with ten replicates of 14 birds. The dietary treatments were: a control group (with uncontaminated corn), the MC group (where half of the corn in the control diet was replaced with the naturally contaminated moldy corn caused 7.6, 8.61, and 8.94 ppb aflatoxin B1 (AFB1) in the starter, grower, and finisher diets, respectively), and the MCTrp group (the MC diet plus 0.1% L-tryptophan). Feeding the MC diet significantly impaired (P < 0.05) body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR), as well as carcass yield and the relative weights of breast and thigh, compared to the control group. The birds fed the MC diet had lower (P < 0.05) intestinal weight and villus height (VH). Feeding the MC diet led to deteriorated (P < 0.05) gait scores and induced femoral head necrosis (FHN). Tryptophan supplementation (MCTrp) was effective (P < 0.05) in alleviating the adverse effects of moldy corn inclusion on VH, gait score, serum alanine transaminase (ALT), and interleukin 6 (IL-6). In conclusion, marginally exceeding regulatory limits of mycotoxins in naturally contaminated corn impairs the performance and health of broiler chickens, and dietary tryptophan supplementation can mitigate some of the negative effects caused by the mycotoxins.