Effects of the tricothecene mycotoxin diacetoxyscirpenol on fertility and hatchability of broiler breeders

Two experiments were conducted to determine the effects of 4,15-diacetoxysc irpenol (DAS) on fertility and hatchability of broiler breeders. Ln Experim ent 1, naturally mated broiler breeders were studied. A limited daily alloc ation of feed containing 0 (basal), 1.25, 2.5, or 5.0 mg DAS/kg diet was pr ovided from 67 to 69 wk of age in slat-litter floor pens. Fertility was con sistently improved by the 5.0 mg/kg level of DAS and intermittently by the 1.25 and 2.50 mg/kg levels. The effect disappeared upon removal of DAS. In Experiment 2, individually caged broiler breeder males and females were fed a basal diet containing 0, 5, 10, or 20 mg DAS/kg diet from 25 to 27 wk of age. Semen was pooled from males within each treatment and used to inse minate females from each treatment in a 4 x 4 factorial design. Female-rela ted fertility was increased at the 5 and 10 mg DAS/kg levels and male-relat ed fertility was decreased by the 10 and 20 mg DAS/kg levels. Small, fluid- filled cysts were observed on the testes of many DAS-treated males upon nec ropsy. In summary, low levels of DAS (less than or equal to 10 mg DAS/kg) appeared to improve female-related fertility, presumably because of enhanced sperma tozoal storage within the oviduct. Conversely, DAS (greater than or equal t o 10 mg DAS/kg) decreased male-related fertility, presumably by direct toxi c effects on the testes. Overall, it appeared that levels of DAS below 5 mg DAS/kg feed would not be detrimental to fertility and hatchability.