EXPERT ADVICE
Six Essential Practices for
REPRODUCTIVE EFFICIENCY By Lee Jones, DVM, MS, University of Georgia
R
eproductive efficiency is crucial for cow/calf herd production and profitability. Without pregnancies, calves aren’t born or weaned and sold. Pregnancy has significantly greater economic impact than any other production trait, and reproductive efficiency is more important than growth or carcass traits for the cow/calf producer. There are a lot of things that challenge reproduction in our cow herds. While fertility is the single most significant factor for cow herd success, infertility is considerably costlier than scours, calf respiratory disease or any other non-fatal disease. Infertility can be defined as a cow failing to breed, breeding but not delivering a live calf, or breeding late. The fact is that if the calf isn’t born alive and healthy and weaned, we don’t have anything to sell. There are six key management areas essential for reproductive efficiency for beef cow/calf programs: heifer fertility, cow herd management, bull fertility, controlled calving season, pregnancy diagnosis, and culling. Heifer Fertility Selecting heifers for fertility and longevity is essential for lifetime productivity. Numerous studies have shown that heifers that breed early and calve early (first 21 days of controlled calving season) are more productive over their lifetime and stay in the herd longer than heifers that calve later. Heifers that calve early as 2-year-olds and maintain early 18 BRAFORD NEWS l FALL 2020
calving throughout their lifetime can produce 100 pounds more calf each year than heifers that calve two cycles later. Traditional methods of heifer selection rely on physical traits such as weight, age and pregnancy status to determine who to keep. Genomic tools show potential to improve our ability to identify the more productive heifers earlier than traditional, phenotypic selection tools. However, selecting heifers by physical traits and overall phenotype is still a valuable tool to build a fertile cow herd. Proper management and selection of heifers that will conceive early is critical. The use of estrus synchronization and AI to breed heifers at the beginning of the breeding season is also an effective tool to produce productive heifers that have longevity. Cow Herd Managing body condition of the cow herd is the best practice to maintain reproductive performance in herds. The cow’s body condition at calving determines her opportunity to get bred in the next breeding season. Cows that calve in poor body condition (BCS 4 or less on a 1-9 scale) likely will not be cycling when the bulls are turned out and have fewer opportunities to get bred than a cow that calves in good BCS. Cows that calve in BCS of 5 or 6 are usually cycling by 60 days after calving and have a better chance of maintaining a 12-month calving interval. Likewise, if a cow calves late
