ADSA Foundation Scholar Award - Reproductive loss in high-producing dairy cattle: Where will it end?

The dairy industry in the United States has changed dramatically in the las t decade. Milk production per cow has increased steadily because of a combi nation of improved management, better nutrition, and intense genetic select ion. Dairy farms are larger, and nearly 30% of the dairy cows in the United States are on farms with 500 or more cows. The shift toward more productiv e cows and larger herds is associated with a decrease in reproductive effic iency. Cows with the greatest milk production have the highest incidence of infertility, but epidemiological studies suggest that, in addition to milk production, other factors are probably decreasing reproductive efficiency in our dairy herds. The reproductive physiology of dairy cows has changed o ver the past 50 yr, and physiological adaptations to high milk production m ay explain part of the reproductive decline. Critical areas for new researc h include control of the estrous cycle, metabolic effects of lactation on r eproduction, mechanisms linking disease to reproduction, and early embryoni c mortality. Solving reproductive loss in dairy cows will not be easy becau se only a small number of research groups study reproduction in postpartum dairy cows. Therefore, the present research base will need to be expanded. For this to occur, research funding must be increased above its current lev el and a renewed emphasis must be placed on solving the emerging crisis of infertility in dairy cows.