Improving Reproductive Efficiency in Heifers

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To improve the reproductive efficiency, and thus profitability, of a beef cattle operation, you must understand proper heifer development. Properly managing yearling heifer reproduction is the first step toward reproductive efficiency.  Your goal is to manage heifers so they’ll conceive early by reducing the age of puberty, shortening the time from puberty to conception and increasing fertility.

UK Extension Beef Specialist Drs. Les Anderson and Darrh Bullock agree that the age at puberty is the most important factor in managing heifer reproduction. For puberty to occur, a heifer should weigh at least 67 percent of her expected mature weight. This percentage of mature weight is a heifer’s “target weight.”

Most heifer development programs require that heifers reach the target weight by the onset of their first breeding season. For maximum fertility and reproduction, heifers must have at least one estrus before the breeding season begins. UK Extension research shows that fertility increases about 20 percent from the first to third estrus after puberty. Thus, it’s logical to manage heifers to reach puberty before the start of breeding season.

Crossbreeding is another management practice to reduce heifers’ age at puberty.  Crossbred heifers, with a genetic makeup of not more than 75 percent of one breed, have a significantly reduced age at puberty compared to straight-bred heifers. Crossbred heifers also have greater overall fertility resulting from hybrid vigor.

Drs. Anderson and Bullock suggest to examine the cowherd to determine the cows’ approximate weights and use these data to set the heifers’ target weights. Then, determine how much heifers must gain daily to reach the target weight. Once you determine the necessary daily weight gain, develop a ration that provides the proper nutrients to help heifers reach the target weight. Periodically weigh heifers to ensure that they’re gaining the appropriate weight. If not, adjust the ration to compensate.

Also, be sure heifers are properly vaccinated according to label and veterinarian recommendations.

Breeding is the final step in managing heifer development. It’s advisable to consider estrus synchronization and/or artificial insemination. Some advantages of estrus synchronization are potentially higher pregnancy rates; heavier, more uniform calves at weaning; and increased production and labor efficiency. Using AI gives producers the ability to use superior, more predictable sires.

Most calving problems occur when heifers have calves for the first time; thus, there is merit in using estrus synchronization and AI with bulls of proven calving ease on first-calf heifers.

By getting heifers bred as early as possible, you give them more time to rebreed after calving. For more information about cattle reproductive efficiency or other cattle topics, contact the McLean County Cooperative Extension Service at (270)273-3690.  Educational programs of the University of Kentucky Cooperative Extension Service serve all people regardless of race, color, age, sex, religion, disability or national origin.