Relative importance of dietary aflatoxin and feed restriction on reproductive changes associated with aflatoxicosis in the maturing White Leghorn male.

A study was conducted to investigate the relative contribution of dietary aflatoxin and feed restriction on reproductive and endocrine changes associated with aflatoxicosis. Pair-feeding was used to factor out nutritional and toxicological effects of aflatoxin on reproduction in the maturing White Leghorn male. Birds were randomly assigned to treatment groups at 9 weeks and fed experimental diets for 3 weeks. Experiment 1 involved the partitioning of toxicological and nutritional effects of aflatoxin on both physiological and reproductive parameters. Aflatoxin-fed males had significantly greater relative liver weights and liver lipid content than control or pair-fed males; no differences in testicular weights were found among treatments. Plasma testosterone levels in controls were significantly higher than in pair-fed birds; aflatoxin-treated males exhibited the lowest concentrations. Pituitary and testicular responsiveness to synthetic luteinizing hormone-releasing hormone (LHRH) were monitored in Experiment 2. Plasma luteinizing hormone (LH) levels in aflatoxin-fed males were significantly higher than in control or pair-fed males prior to LHRH administration. Additionally, the LH response of pair-fed birds to exogenous LHRH was qualitatively different from that observed in the other two treatments; this indicates that hormonal changes observed during aflatoxicosis and feed restriction are a result of different physiological mechanisms. Plasma testosterone also increased after LHRH injection. This response was significantly greater in controls than in pair-fed males, and nonexistent in aflatoxin-treated birds.(ABSTRACT TRUNCATED AT 250 WORDS)