Reproductive wastage following artificial insemination of heifers
Roche, J.F.; Bolandl, M.P.; McGeady, T.A.
Veterinary Record 109(18): 401-404
1981
ISSN/ISBN: 0042-4900 PMID: 7340073 Document Number: 173109
Hereford crossbred beef heifers (303) at pasture were inseminated artificially at detected oestrus and slaughtered between 3 and 28 days later. Ova were recovered from 87% of 60 killed after 3 days, and 77% of 71 heifers killed after 8 days. Proportions pregnant after 14, 18 and 28 days were 75, 60 and 62% resp. It was concluded that fertilization failure accounted for up to 20% of reproductive wastage. Embryonic mortality occurring between 8 and 18 days after insemination accounted for most of the remaining wastage.