LIMOUSIN TODAY October_LimToday_WEB - Page 16

Management Preg Check and Cull Open Replacement Heifers By Glenn Selk, Oklahoma State University Many ranchers choose to breed the replacement heifers about a month ahead of the mature cows in the herd. In addition, they like to use a shortened 30 to 60-day breeding season for the replacement heifers. The next logical step is to determine which of these heifers failed to conceive in their first breeding season. This is more important today than ever before. The bulls were removed from the replacement heifers about 60 days ago, therefore, this would be an ideal time to call and make arrangements with your local large animal veterinarian to have those heifers evaluated for pregnancy. After two months of gestation, experienced palpaters should have no difficulty identifying which heifers are pregnant and which heifers are not pregnant (open). Those heifers that are determined to be “open” after this breeding season, should be strong candidates for culling. Culling these heifers immediately after pregnancy checking serves three very economically valuable purposes. 1. Identifying and culling open heifers early will remove sub-fertile females from the herd. Lifetime cow studies from Montana indicated that properly developed heifers that were exposed to fertile bulls but DID NOT become pregnant were often sub-fertile compared to the heifers that did conceive. In fact, when the heifers that failed to 14 | OCTOBER 2018