Objective—To determine effects of breed and oral vitamin E supplementation during late gestation on serum vitamin E and IgG concentrations in beef cows that calved in late winter and late summer and in neonatal calves.
Animals—73 Angus and 43 Hereford primiparous and multiparous cows and their calves.
Procedure—Cows in groups that were homogeneous regarding breed and age distribution were randomly allotted to groups that were orally supplemented (n = 59) or not supplemented (57) with vitamin E beginning 30 days prior to onset of 65-day calving seasons. Supplemental vitamin E was provided in a vitamin-mineral mix offered free-choice until parturition.
Procedure—Cows that calved in late winter and were supplemented orally with vitamin E had higher serum vitamin E concentrations at calving and after calving than did unsupplemented cows; differences between groups before calving were not significant. Calves from supplemented multiparous cows had higher vitamin E concentrations than did calves from unsupplemented cows. Winter-born calves from supplemented Hereford cows had heavier 205-day adjusted weaning weights than did winter-born calves from unsupplemented Hereford cows. Supplementation did not affect vitamin E or IgG concentrations in the herd that calved in late summer and did not affect calf growth.
Conclusions and Clinical Relevance—Oral vitamin E supplementation during late gestation may be economically beneficial in certain cow-calf operations in which late-gestation cows are consuming stored forages. ( Am J Vet Res 2001;62:921–927)