Ask the Vet

By Dr. Ken McMillan
DTN Contributing Editor

QUESTION:

Do you have a suggested program to make sure bulls are ready for breeding season?

ANSWER:

Several months before your turnout date, you need to decide if any bulls should be replaced. Then consider whether you have enough bull power to get through the breeding season. Remember, your bulls contribute 50% of the genetics to each calf crop, so having enough quality bulls to do the job is extremely important. Never be in a last-minute rush to find a bull.

If you need to add a bull or bulls to the herd, virgin bulls help avoid introducing diseases. But, all new bulls should be quarantined three to four weeks. Ideally, nonvirgin bulls should be tested for vibrio, leptospirosis and trichomonas. This is especially important for bulls purchased from a sale barn or those with an unknown history.

I recommend having your veterinarian do a complete Breeding Soundness Exam (BSE) on every bull 30 to 60 days prior to breeding season. This gives you time to find additional bulls if there's a problem. A BSE must include a physical exam to make sure the bull is sound and able to breed. Each bull must meet minimum requirements with regard to scrotal circumference, motility and normal sperm to be classified as a "satisfactory potential breeder."

Bulls should also be vaccinated at this time if due. Your herd veterinarian is the best person to decide the preferred program, but, in my mind, core vaccinations should include IBR (infectious bovine rhinotracheitis), BVD (bovine viral diarrhea), PI3 (parainfluenza virus 3), BRSV (bovine respiratory syncytial virus) and leptospirosis. Other vaccines including vibrio (Campylobacter) and trichomonas may be needed in some herds. Most bulls should also be treated for internal and external parasites prior to breeding season.

I know this sounds like a lot, but the cost of a completely sterile bull (and I have found several in 37 years) can exceed $30,000 in losses. Even a subfertile bull can cost you thousands in lost conceptions. So, a BSE and a current health-care program are a small price to pay to make sure you're getting full use of your resources.

Lastly, remember body condition is important on bulls. At turnout, I recommend they be at a body condition score (BCS) of around 6. Bulls that are too fat, especially if on full feed, "melt" when turned out with cows. Feeding a quality mineral year-round is essential in keeping bulls at their best.

If bulls are to be used in multisire groups, they should be introduced to each other prior to turnout. I've found this can help minimize fighting and injuries when they should be breeding cows.

(SK)

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