UNIVERSITY OF IDAHO
Be sure to practice sound management of newly purchased bulls Proper health and nutrition, and then mixing and monitoring your herd, help ensure a good breeding season BY JOHN B. HALL, PH.D.
Extension Beef Specialist, University of Idaho It’s hard to believe it is bull buying season already. It is always fun and exciting attending sales and looking for the next herd sire. And that new bull is a big investment. Bull prices in recent years have been strong but reasonable; still, most producers are paying more for bulls than they have in the past. The key to keeping this investment working for the operation for the next three, four or more years is good management of young bulls. 50
LINE RIDER FEBRUARY 2022
ICA ARCHIVE
IMPACT OF POST SALE WEIGHT LOSS ON BULL FERTILITY
BIOSECURITY AND HEALTH
Make sure you know the vaccines the bull has received before you take him home. Get the exact name of the products used and when they were given. Share this information with your veterinarian and discuss whether any additional vaccines are needed. If another round is recommended, it should be given at least 30 days before the start of the breeding season. Ideally, new bulls, like all purchased additions to the herd, should be kept away from the existing bull battery and cow herd for three weeks. Most places don’t have the ability to keep bulls from multiple sales separate, so putting all newcomers together is often the only option. Bulls that get sick and need to be treated should not be mixed with the herd until given the OK by your veterinarian.
CREDIT: BARTH ET AL., 1995
NUTRITION
Most bulls have been developed on diets that are greater in energy and protein than what typical cow/calf operations feed. In some cases, these bulls may be a little too fat. However, bulls that lose too much weight become infertile. Canadian researchers retested newly purchased bulls for fertility immediately before the start of the breeding season. In most cases, if bulls lost more than 100 to 150 pounds, their fertility was negatively affected (see chart above). Remember that young bulls (15-30 months) are still growing. In fact, bulls don’t reach their mature size until they are 4 or 5 years old. So the strategy is CONTINUED, PAGE 52 www.idahocattle.org
