Reproductive physiology and management of high-yielding dairy
cattle
M.C. LUCY
Department of Animal Sciences, University of Missouri, Columbia,
Missouri 65211, USA
E-Mail:
Proceedings of the New Zealand Society of Animal Production 2001. 61:
120-127
The future efficiency of the dairy industry will undoubtedly be
affected by the decline in fertility and reproductive efficiency in
modern dairy cows. The cause of the declining fertility is probably a
combination of genetic, physiological and management factors that have
an additive effect on reproductive efficiency. Milk production per cow
has increased and is one factor that is contributing to the problem. In
addition to milk production, however, many other equally important
factors may be involved. For example, the reproductive physiology of
dairy cattle has changed in response to genetic selection for milk
production and these changes may require different management
strategies. Compared to traditional dairy cows, modern dairy cows have
longer intervals to first ovulation, a higher incidence of anoestrus,
abnormal luteal phases, lower blood progesterone concentrations, and
greater embryonic loss. Reproductive decline can be reversed in dairy
cows but a collective effort that includes more intense reproductive
management, genetic selection for improved fertility, and new scientific
discoveries will be necessary before the problem can be solved.
Keywords: NZSAPAB;
dairy; reproduction; milk yield; management
Last Updated 7/08/01
