Beef reproductive success means “stacking the deck” in all the right ways

Farm Forum

It’s hard to believe, but it’s already time for cattle producers to start thinking about next year’s calving season. Breeding season is right around the corner!

Every spring I get calls from worried cattlemen who face the breeding season with apprehension. For these individuals, last year’s breeding season did not go well. Too many open cows at preg-check time, too many late-calving cows, and too many late-gestation pregnancy losses. I come into the conversation to help answer the question, “What happened?”

Unfortunately, obtaining the answer to that question is usually difficult. A list of many factors–some bull-related, some cow-related, some related to environment–need to work together in order for a successful breeding season. It’s our nature to want to find the one thing that went wrong: the weed in the pasture, the vaccination program, or the hot spell. But it’s rare to find only one factor at play.

In some areas, there were additional questions this winter stemming from the epizootic hemorrhagic disease (EHD) cases we saw last summer. The signs of EHD were generally mild in a few animals per herd, but cattle producers were curious about possible reproductive effects of EHD in their cows this calving season. The good news is that we have not observed significant reproductive effects in the herds confirmed with EHD last summer.

There is no single vaccine, feed supplement, or management strategy that ensures a great calf crop year after year. Cattle producers with consistent success at reproduction realize this. Instead of making an annual quest for the one “silver bullet” that will solve all problems, they do several things to “stack the deck” in their favor. By doing so, they increase the odds that, if some part of their program falls down, other aspects of their approach will help make up the difference.

What are some of those things you can do to “stack the reproductive deck” in your favor?

1. Make sure all bulls pass a complete breeding soundness examination (or “semen test”) performed by a veterinarian prior to turnout. The month prior to turnout is a good time to do this, but you’ll want to allow time to restock your bull battery or to retest questionable bulls if some of them do not pass.

2. Trichomoniasis has popped up again in South Dakota. If you had too many open or late cows last year have your vet test your holdover bulls for trich. This can be done at the same time as the breeding soundness exam. Trichomoniasis is carried by bulls long-term and you might not know your herd is affected until preg-check time this fall.

3. Vaccinate cows and bulls for infectious diseases that may affect reproduction, such as IBR, BVD, Leptospirosis and Vibriosis. It’s best to do this 4 weeks or so before turnout. Your veterinarian will have the best guidance for you about products and timing.

4. Pay attention to cow body condition, especially coming second-calf heifers and older cows. Although time is not on our side to bring these females back up to condition by the time we want them to breed, take steps now to segregate groups and provide supplemental feed.

5. Don’t try to stretch the bulls too thin. A rough rule of thumb is 1 bull/25-30 head of cows, and more than one per pasture. Adjust up or down depending on the bulls and pastures. Using only bulls that have passed a breeding soundness exam will give you more confidence in situations where your bulls might be stretched thinner than you like.

6. Watch bulls on pasture and respond quickly to problems such as lameness, pinkeye, or breeding injuries. Don’t underestimate the hit that fertility takes when something like foot rot or pinkeye affects a bull.

7. Wait to move females until 60 days post-breeding, or when using AI, do it right away (days 1-4 post-breeding). Embryo survivability is decreased when bred animals are moved at the wrong times.

The complexity of reproduction means that successfully raising a calf crop comes down to doing a lot of the boring things right instead of trying to find the one program or product that will make all the difference.

Russ Daly, DVM, is the Extension Veterinarian at South Dakota State University. He can be reached via e-mail at or at 605-688-5171.