Trends in qenetic meritfor dairy cow fertility

摘要

Achieving a high level of dairy cow fertility is underpinned by four key factors: providing adequate nutrition throughout the year; a high level of disease control; careful management of the breeding season and breeding for greater genetic merit for fertility. It is the trends in genetic merit for fertility in the context of an expanding national dairy herd and their likely implications for the veterinary profession that is the focus of this article. The introduction of the Economic Breeding Index (EBI) in 2000 was primarily prompted by a decline in the genetic merit for fertility in the Irish dairy herd (Evans et al, 2006). Initially confined to milk and fertility sub-indices, the current EBI has been expanded to include seven traits of economic importance. The milk and fertility sub-indices, however, remain the most important accounting for approximately one third each of the weighting within the EBI. In this article, however, I'm focusing on the trends, outcomes and likely impacts of the rapid improvement in genetic merit for fertility, The rate of genetic improvement in dairy cow fertility is accelerating in an expanding national dairy herd and the combination of the two will change the nature ofveterinary interventions required on Irish dairy farms in the coming years.