Effects of dietary supplements of folic acid on reproductive performance in ewes

Abstract

The objective of this project was to assess the impact of periconceptional folic acid supplementation on the reproductive performance of prolific and non-prolific ewes, in the estrous and anestrous seasons. Two initial trials took place during the estrous season at two experimental sites where 38 Dorset and 39 half-Finn half-Dorset ewes (site A) as well as 80 Dorset ewes (site C) were divided into two groups receiving either 0 or 210 mg ewe-1 d-1 of folic acid over a period which extended from 21 d premating to 30 d postmating. Three other trials were conducted in the anestrous season where 80 Dorset ewes (site A), 56 half-Romanov ewes (site B) and 78 Dorset ewes (site C) were subjected to the same protocol as the one used in the breeding season. In all the trials, the folic acid supplement increased plasma and red cell folates, but had no effect on fertility, embryonic mortality, or the size or weight of the litter at birth. Folic acid supplementation did not improve the reproductive performance of prolific and non-prolific ewes, either in the estrous season or in the anestrous period. Key words: Ewes, reproduction, vitamins, folic acid, fertility, prolificacy