Reproductive physiology of the heat-stressed dairy cow: implications for fertility and assisted reproduction

Strategies for managing reproduction in the heat-stressed dairy cow.

Establishment and maintenance of pregnancy is difficult in lactating dairy cows exposed to heat stress because of reductions in estrous detection rate and the proportion of inseminated cows that maintain pregnancy. The most common approach to ameliorate heat stress in developed countries has been to alter the cow's environment through provision of shade, fans, sprinklers, and so on. Nonetheless...

Nutritional strategies for managing the heat-stressed dairy cow.

Heat stress results from the animal's inability to dissipate sufficient heat to maintain homeothermy. Environmental factors, including ambient temperature, radiant energy, relative humidity, and metabolic heat associated with maintenance and productive processes, contribute to heat stress. The focus of this article is to identify environmental and metabolic factors that contribute to excessive ...

Crossbreeding: implications for dairy cow fertility and survival.

In pasture-based seasonal calving systems, failure to become pregnant during the breeding season results in important economic losses as maximum profit is attained by minimising costs and increasing the proportion of grass in the diet of the lactating dairy cow. In the United States, dairy producers primarily strive to maximise production potential but are becoming increasingly aware of the eco...

Dietary Fatty Acids and Dairy Cow Fertility

Strategies for improving fertility in the modern dairy cow.

The high producing dairy cow of the 21st century is subfertile during lactation. Our objectives are to characterize physiological periods limiting reproductive performance and to describe integrated management strategies to improve pregnancy rates. Ovarian recrudescence with normal re-occurring estrous cycles and restoration of fertility to first service are associated with a reduced occurrence...