Impact of high dietary vomitoxin on yolk yield and embryonic mortality.

Single Comb White Leghorn hens at 58 weeks of age were given control (C) and vomitoxin (V)-contaminated feed for 4 weeks; then the V treatment was changed to C for 2 subsequent weeks. Fusarium graminearum-infected corn was substituted for sound corn to attain a practical extreme of 38 ppm V. Hen-day production, feed consumption, body weight, and gross pathology were the same between treatments. Egg weight, internal quality, and shell strength were not adversely affected; however, dietary V led to a small reduction in the percentage of yolk while albumen increased. Solids content of both egg components remained unchanged, and no V as such could be detected (less than .2 ppm). Presence of toxic V metabolites in the egg were indicated by increased (although still low) embryonic mortality upon incubation. Improvement in yolk yield and relief from germ losses occurred 1 week after the change from V to C feed. Overall responses to present extreme circumstances were no greater than variation occurring between weeks, and problems in practice seem remote.