Use Heifer Pre-Breeding Exams As A Culling Tool And To Prepare For Breeding Season
PATRICK DAVIS
STOCKTON, MISSOURI
“As cattle producers rebuild their cattle herds, the focus may be to retain heifers as replacements,” says Patrick Davis, University of Missouri Extension livestock field specialist. Breeding season will soon be upon us, and it is important to retain heifers that are good breeding prospects. Therefore, Davis will discuss the pre-breeding exam, which cattle producers should do 30 to 60 daysprior to the breeding season to identify those heifers to retain as good breeding prospects.
“The reproductive tract is evaluated during the pre-breeding exam to help cattle producers determine those heifers that are mature enough to become pregnant during the breeding season,” he says. A veterinarian through rectal palpation identifies on a 1 to 5 scale the reproductive tract’s maturity. Heifers that score a 1 or 2 are less likely to become pregnant during a 60-day breed season and should be culled. Heifers that score 3, 4 or 5 are more likely to become pregnant during the 60-day breed season and should be retained. Look at MU Extension guide G2028 to find more information on reproductive tract scoring.
“Pelvic area is also measured during the pre-breeding exam,” says Davis. The veterinarian through rectal palpation measures the width and height of the pelvic opening to determine if the area is adequate for the heifer to have her first calf with ease. The Missouri Show-Me-Select Replacement Heifer Program requirement is that heifers need to have a pelvic area of 150 cm2 or greater at pre-breeding exam time. If the heifer fails that measurement, then to be acceptable their pelvic area must measure 180 cm2 or greater at pregnancy check, which is within 90 days of the beginning of the breeding season. For more information on heifer pelvic area and calving difficulty, look at MU Extension guide G2017. Davis urges this management strategy in addition to breeding the heifers to a calving-ease bull to reduce dystocia issues at calving time.
“Work with your veterinarian to plan and update the heifer’s vaccinations at pre-breeding time,” says Davis. In addition to what is mentioned above, consult your veterinarian to have an adequate vaccination and parasite control plan for your operation so that heifers are successful during the breeding season. For suggestions on a vaccination program, look at MU Extension guide G2024.
“Evaluate body condition score (BCS) and weight of the heifers during the pre-breeding exam to make sure they are adequate to be successful during the breeding season and as cows,” says Davis. BCS represents the fat cover on the cow and is evaluated on a 1 to 9 scale, with 1 being extremely thin or emaciated and 9 being obese. BCS is linked to energy status, reproductive efficiency, longevity and profitability of the cowherd. Davis suggests heifers be at a BCS of 5 to 6 and weigh 55% to 65% of their mature body weight at pre-breeding time to promote optimum cattle herd reproductive efficiency, longevity and profitability. For more information on cow body condition score management as it relates to reproductive efficiency, look at MU Extension guide G2230.
“Evaluate structural soundness during the pre-breeding exam to make sure heifers have adequate soundness for optimum longevity in the herd,” says Davis. Females with poor structure may have reduced longevity in the herd. Furthermore, if replacements are retained, these poor-structure genetics are propagated through the herd. Foot scoring is one way to evaluate structural soundness in females. Foot angle and claw set are the measurements evaluated during foot scoring. These measurements are evaluated on a 1 to 9 scale, with an ideal range of 3 to 7. For more information on foot scoring related to selection of heifers at pre-breeding time, look at MU Extension guide G2093. Davis urges cattle producers to cull females that don’t have optimum structural soundness and don’t fall in the ideal range for foot scoring.
“Heifer selection and development is important to the next generation and profitability of the cow herd,” says Davis. Use management strategies mentioned above at pre-breeding time to select the best females possible to promote longevity, reproductive efficiency, productivity and profitability in the cowherd. For more information on management of replacement heifers at pre-breeding time, contact your local MU Extension livestock field specialist. ∆
PATRICK DAVIS: University of Missouri