Abstract

There has been a documented decrease in fertility in the modern dairy cow selected for milk yield (Pryce et al.,2004). This emphasises the need for farmers in a seasonal grass-based system such as that in New Zealand to correctly manage herd genetics in conjunction with nutrition to optimise cow reproductive performance. The question remains however as to the relative influence and interdependence of these two factors in establishing a pregnancy, as an optimal size for the ovulatory follicle is directly related to successful conception and pregnancy (Perry et al., 2005).

MP, Green, PJ Back, and MC Berg

Proceedings of the New Zealand Society of Animal Production, Volume 70, Palmerston North, 303-305, 2010