Overview of Management of Reproduction: Cattle
Dairy and beef producers should strive to increase reproductive efficiency as a key driver of economic efficiency in the sector. Reproductive efficiency, or "pregnancy rate," is defined as the proportion of cows eligible to be bred that become pregnant during an estrous cycle (or approximately 21 days), and which determines the calving to conception interval at the end of the voluntary waiting period. As pregnancy rate increases in dairy herds, the calving to conception interval decreases, and the herd status becomes, on average, less "days in milk" (DIM). This has the effect of increasing the potential amount of milk produced per day of herd lifetime, because yield classically declines at 0.3% per day after peak lactation production. A major and realistic goal of every beef cow/calf operator should be to raise or market 85 calves per 100 cows every year. Greater reproductive efficiency also reduces the number of cows culled for reproductive failure; collectively, these changes increase herd income.
Reproductive performance in both beef cow/calf and dairy operations can be improved by the following: 1) properly identifying and managing animals to carry out reproductive programs; 2) keeping records that enable determination of important herd indices, such as percent calf crop, pregnancy rate, length of calving season, culling rates, calf morbidity and mortality, breeding efficiency of bulls, and performance and production information; 3) meeting the nutritional requirements of various classes of livestock in the herd, emphasizing nutritional needs and cost efficiencies; 4) establishing a breeding program for heifer replacements and cows; 5) practicing sire selection and reproductive management; 6) adopting a vaccination/immunization program for the cow/calf herd, bulls, and calves; 7) evaluating reproductive failure and abortions; 8) providing adequate facilities; and 9) ensuring that the calf is well cared for at birth and receives adequate colostrum.