Replacement heifers should be females that will be productive cows for years to come
Replacement heifers are a common factor in many cattle operations across the Ozarks.
Replacement heifers may all come from the same calf crop, but not all are created equal. Proper replacement heifer evaluation and management will help a producer make the best selections for their herd.
Having a relatively uniform set of standards will help producers effectively measure the heifers they are raising or purchasing for certain traits that will be beneficial to their program. Looking at the herd goals can give producers an idea of what they need to select for.
Exams are Important
A pre-breeding exam is an ideal component in evaluating replacement heifers, according to University of Missouri Extension Livestock Field Specialist Erin Larimore.
“The best method for evaluating heifers for breeding would be to perform a pre-breeding exam where a reproductive tract score and pelvic measurement are assigned to each heifer,” she explained. “A reproductive tract score (RTS) assesses the cyclicality status of heifers, which lets us know if they have reached puberty and are cycling or not. The pelvic measurement is used to reduce odds a heifer will experience calving problems when bred to a bull with proper calving ease.”
The bulls being utilized for producer’s chosen replacement heifers should ideally have a breeding soundness exam and have EPD data to ensure he is an appropriate match. Larimore noted a heifer’s age and size, as well as breed, will influence their tract scores and pelvic measurements, making a pre-breeding exam even more important to give the producer an accurate RTS.
Fine Tune Management for Uniformity
A heifer crop that matures and reaches puberty in a uniform fashion gives the producer more to choose from. Larimore explained it is recommended heifers achieve 65 percent of their mature body weight by breeding time, so a producer’s management plan should be geared towards keeping heifers on track to gain and reach that weight.
“I think this also goes back to the cowherd,” Larimore said. “Having a shortened breeding and calving seasons for the cows will mean a more uniform group of heifers. Utilizing fixed-time artificial insemination can frontload the calving season and those cows that conceive to AI will have older, heavier calves.”
Early Pregnancy Rates Are Beneficial
Selecting only heifers that become pregnant early (to the first artificial insemination or during the first 21 days of a natural-service bull exposure) can have major impacts on herd reproductive rate and productivity. Heifers becoming pregnant early have greater longevity and wean heavier calves compared to heifers becoming pregnant later in the breeding season.
Raise or Buy
“For many operations, it winds up being more economical to buy quality replacements than it is to raise them on your own,” Andy McCorkill, University of Missouri Livestock Field Specialist, said. “However, there is a lot of personal satisfaction that comes out of seeing the progress in your herd over the years and you always know what you have and how the heifers were developed if you do it on your own.”
Set Heifers Up for Success
Once a producer has gone to all the work to carefully select replacement heifers, it pays to give the young ladies a little extra TLC. Dr. Eric Bailey, MU Extension State Beef Specialist, advised producers to feed and manage heifers separately to ensure they get what they need.
“Most beef heifers calve at 85 to 90 percent of their mature size, and they are still growing,” he said.
There has been concern among producers that feeding a first-calf heifer too much in her final trimester will cause her calf to grow too large and create problems during delivery. Due to a heifer’s still growing body, however, this is rarely the case. Bailey advised producers to keep food in front of first calf heifers to set them up for both calving and rebreeding success.
