Abstract

Reasons for a temporary infertility syndrome in pasture-fed dairy cows were sought. Low submission and conception rates in 35 mature Friesians (either of high or low breeding index) were associated with low plasma albumin and glucose concentrations at the commencement of mating and poor body condition prior to calving. Discriminant function analysis indicated that albumin concentration was the most important variable in the allocation of cows to "fertility" groupings. Breeding index and level of milk production were relatively unimportant. A disturbance in protein metabolism was implicated as the cause of the infertility syndrome. A concentrate supplement containing 19% crude protein, fed to monozygous twin cows at 1.4 kg/d for 3 weeks prior to mating led to a marked improvement in conception rate.

AM, Bryant, MAS Cook, and KA MacDonald

Proceedings of the New Zealand Society of Animal Production, Volume 45, , 7-12, 1985