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Submitted to: Meeting Proceedings
Publication Type: Proceedings Publication Acceptance Date: 1/6/2008 Publication Date: 3/20/2008 Citation: Geary, T.W. 2008. Management of Young Cows for Maximum Reproductive Performance. Proceedings XII Course on New Approaches to Production and Reproduction in Cattle, March 6-7, 2008 Uberlandia, Brazil(Portuguese only)CD only pg 17-25. Interpretive Summary: The most common problem that cow calf producers face in the U.S. is low rebreeding performance among two- and three-year old cows. In Brazil, however, most cows are not bred until at least 2 years of age. However, the underlying reason that young cows in both countries have difficulty re-breeding is due to the need for additional nutrient requirements for growth in addition to lactation. There are several strategies to increase the re-breeding performance of these females including use of crossbreeding, providing adequate heifer development, providing early calving assistance when needed, calving in adequate body condition, providing adequate prepartum and postpartum nutrition, use of bull exposure, hormonal strategies, ionophores, and/or temporary or permanent calf removal. Many of these strategies are applicable to producers in both countries with the possible exception of crossbreeding in which Brazilian cattle may need to contain at least 50% Bos indicus genetics to thrive in a tropical environment. Combinations of the above strategies may improve a producer’s chances of getting a high percentage of young cows pregnant. Technical Abstract: The most common problem that cow calf producers face in the U.S. is low rebreeding performance among two- and three-year old cows. In Brazil, however, most cows are not bred until at least 2 years of age. However, the underlying reason that young cows in both countries have difficulty re-breeding is due to the need for additional nutrient requirements for growth in addition to lactation. There are several strategies to increase the re-breeding performance of these females including; 1. Make sure heifers are adequately developed (65% of mature weight) before the start of her first breeding season. 2. Consider breeding heifers with artificial insemination to calving ease proven sires during a short breeding season. 3. Plan to breed heifers approximately three weeks ahead of the cow herd to allow heifers more time after calving to resume cyclicity. 4. Provide early calving assistance when intervention is needed. 5. Provide first-calf heifers with the best nutritional program available during the last 50 days of gestation to be sure that they calve with a body condition score of 5 and continue to improve their nutritional program after calving. 6. Feed ionophores to cows after calving to improve feed utilization. 7. Consider exposing young cows to sterile bulls or androgenized cows during the last 30 days before the start of breeding. 8. Induce and/or synchronize estrous cycles in young cows even when natural service is to be used. 9. Consider early weaning during times of drought and cheap feed availability. 10. Utilize crossbreeding to the maximum extent possible for your environment. Combinations of the above strategies may improve a producer’s chances of getting a high percentage of young cows pregnant. |
