Inadequate Nutrition Results in Ovarian Inactivity, Especially in Cattle
In dairy cattle, genetically selected for high productivity, the ability to produce up to 100 pounds of milk per day is a remarkable achievement. It is almost impossible for dairy cows to consume enough feed during the first part of the lactation cycle to maintain their body weight, and they are often in a negative nutritional balance for up to 100 days postpartum.
Animals must have an adequate level of nutrition to initiate ovarian activity, so ovarian activity is suppressed until a positive energy balance is established. If an owner wants a dairy cow to produce large quantities of milk, the owner must be willing to wait for nutrition to “catch up" with milk production.Inadequate nutrition can affect ovarian activity in the postpartum period. A management practice sometimes used to enhance production efficiency is to maintain beef cows on a marginal plane of nutrition during the winter. This approach forces animals to use fat that has been developed and stored during the grazing season. If pregnant beef cows are not returned to a positive nutritional balance by the last month of gestation, the reestablishment of ovarian cyclicity, which usually occurs between days 45 and 60 postpartum, will be delayed. Another situation that can affect ovarian activity involves pregnant beef heifers. These animals often need extra nutrition in the postpartum period to reestablish ovarian activity because they have requirements for growth as well as for lactation.