The winter of 2010 has broken a number of records. Beef cows on most farms have probably been affected to a significant degree by the winter. The seventy days of snow cover that we experienced in Blacksburg have altered cow diets for the worse while unusually cold temperatures and wind chills have markedly increased nutrient requirements.
A review of what research and experience has taught us about reproductive performance helps us predict and hopefully take steps to remedy the effects of this situation on the upcoming breeding season. Otherwise open cows and later calves may have a profound effect on future profits.
The number of cows that get pregnant during a calving season is a function of three major factors:
Years of research have helped to show the major factors that influence each of these main items. Here are the generally agreed on contributors:
So what’s different this season than most years? Cows lost more weight in the winter and therefore calving at lower body condition scores than usual. That means that they will tend to be slower to cycle than usual. If the average cow begins cycling twenty-one days later that results in about 15% more open cows in a 65-day breeding season.
A wise producer can use the other knowledge we have of the factors that determine outcomes of beef reproduction to overcome this drawback. Here are some procedures that can be done to increase the odds that cows will become pregnant efficiently.
Having a successful breeding season this year will require that typical management be improved in many operations. Utilizing some of the above special techniques, even if they are not necessary in most breeding situations, may pay real dividends this season.
Virginia Cooperative Extension materials are available for public use, re-print, or citation without further permission, provided the use includes credit to the author and to Virginia Cooperative Extension, Virginia Tech, and Virginia State University.
Issued in furtherance of Cooperative Extension work, Virginia Polytechnic Institute and State University, Virginia State University, and the U.S. Department of Agriculture cooperating. Alan L. Grant, Dean, College of Agriculture and Life Sciences; Edwin J. Jones, Director, Virginia Cooperative Extension, Virginia Tech, Blacksburg; Jewel E. Hairston, Administrator, 1890 Extension Program, Virginia State, Petersburg.
March 29, 2010