Abstract

A decline in dairy cow fertility in the USA and in the UK (Beam & Butler 1999; Royal et al. 2000) has also been noted in New Zealand. Calving rate, the proportion of cows re-calving within the first 42 days of the subsequent seasonal calving period, in New Zealand decreased from approximately 70% in 1991 to 60% in 2004 (Harris et al. 2006). There has been no further deterioration in subsequent years.

KJ, Hutchinson, SR Davis, DDS MacKenzie, HT Blair, LR McNaughton, K Sanders, and RJ Spelman

Proceedings of the New Zealand Society of Animal Production, Volume 73, Hamilton, 117-119, 2013