Effect of purified aflatoxin on turkeys.

Purified aflatoxin B1 (AFB1) or AFB1 plus aflatoxin B2 (AFB2) was given daily for 5 weeks in gelatin capsules to 2-week-old Nicholas X Nicholas turkeys. In Experiment 1, pure AFB1 was given in dosages equivalent to the quantity of toxin received if diets containing either 0, 200, 500, or 1000 ppb of AFB1 were consumed. In Experiment 2, either pure AFB1 or AFB1 plus AFB2 was given in capsules equal to the quantity of toxin received if a diet containing either 0, 100, 150, or 200 ppb of AFB1 was consumed. In Experiment 1, pure AFB1 administered by capsule equal to 500 and 1000 ppb was highly toxic and by the second week, it resulted in 100% morbidity, mortality, and gross and microscopic lesions. Aflatoxin B1 at 200 ppb caused none of these changes. However, it did cause a significant depression in feed conversion, but not weight gain, during all weeks and also a reduction in cell-mediated immunity (CMI) as measured by a delayed hypersensitive skin test to mycobacterium. Results in Experiment 2 were similar to the first. Aflatoxin B1 and AFB1 plus AFB2 as high as 200 ppb resulted in no morbidity, mortality, or gross or microscopic lesions. Also, no significant reductions in either weight gain or feed conversion were evident in any level of either AFB1 or AFB1 plus AFB2. However, numerical, but not statistically significant, dose-related reductions in all CMI tests were noted in birds receiving either AFB1 or AFB1 plus B2 at as low as 100 ppb.