By Blake Jackson
For cow-calf operations, maximizing productivity hinges on consistent calf production and longevity of the cow herd. Ideally, each cow should yield a healthy calf annually and remain productive for at least six years to offset initial and maintenance costs.
Selecting suitable replacement heifers is crucial for achieving this. Given current high cattle prices, identifying and culling infertile or problematic heifers early allows them to be sold as feeders, rather than later as less valuable cull cows.
To ensure a heifer's lifetime productivity, she should reach puberty by 15 months, enabling calving at 24 months. However, approximately 35% of heifers fail to reach puberty by this age.
Pre-breeding exams, conducted by a veterinarian, including reproductive tract scoring and pelvic measurements, help identify late-maturing heifers. These exams should occur around 12-15 months, before breeding.
Reproductive tract scores range from 1 to 5, reflecting puberty status. A score of 1 indicates an underdeveloped tract, while a score of 5 signifies active cycling with a corpus luteum present. Higher scores correlate with increased pregnancy likelihood.
Heifers with scores of 4 or 5 have better chances of conception, particularly early in the breeding season, leading to earlier calving. This early calving trend generally continues, enhancing lifetime productivity and profitability.
Pelvic measurements are also vital. Heifers with smaller pelvic areas are prone to difficult births, increasing producer workload and calf mortality. Culling heifers with pelvic areas below 150 cm can mitigate these risks.
The pre-breeding exam is an opportune time to assess other culling criteria, such as structure and temperament, and to administer vital vaccinations.
Recommended vaccinations include those for bovine viral diarrhea (BVD), infectious bovine rhinotracheitis (IBR), bovine respiratory syncytial virus (BRSV), parainfluenza 3 (PI3), and leptospirosis.
Conducting pre-breeding exams on all replacement heifer candidates allows for informed decisions regarding breeding potential and feeder market suitability. This proactive approach optimizes herd productivity and profitability.
For further information on pre-breeding exams and heifer development, contact Elizabeth Picking at the MU Extension Center in Howell County 417-256-2391 or at pickinge@missouri.edu.
Photo Credit: gettyimages-erdinhasdemir
Categories: Missouri, Livestock, Dairy Cattle