Make sure your bulls are ready for breeding season.
By: Rachel Endecott, Beef Cattle Specialist, Montana State University
How do your bulls look? Are they recovering well from breeding season, or do some need a little extra? Mature bulls may be able to get by on an all‐forage diet, but young bulls should be around 75% of their mature body weight by the time they are 2 years old. For example, let’s say you bought a 1250‐pound yearling bull this spring, and he lost 200 pounds during the breeding season and he weighs 1050 pounds. If you expect him to weigh 2000 pounds at maturity, he needs to gain 450 pounds to weigh 1500 pounds (0.75 x 2000) by the time he turns two.
While it is important for thin bulls to achieve optimal body condition, it is also important not to overfeed bulls. Fat layers around the scrotum can interfere with temperature regulation, negatively impacting semen quality and production. Overfeeding can also lead to foot problems and soundness issues, and out‐of‐shape bulls are less likely to hustle to breed cows when turn out time rolls around.
I recommend that bulls receive a year‐round mineral supplementation program just like the cows. Trace minerals like copper, zinc, manganese, and selenium, along with vitamins A and E are important antioxidants that can prevent sperm damage from stress.
Protection from inclement weather is a crtical factor in winter herd bull management. Frostbite can hinder a bull’s ability to raise and lower the testicles for proper temperature regulation. While mild frostbite has a good recovery rate, severe frostbite can leave a bull infertile. Ensure that bulls have the ability to get out the wind and are not lying on unbedded, frozen ground.