Summer Culling
Considerations on adjusting herd size and related biosecurity concerns.
Culling open cows and adding replacement females are strategies for maximizing herd reproductive efficiency. Reproductive status and feed availability often drive those decisions. Culling and biosecurity were two topics of discussion on a recent Kansas State University (K-State) Beef Cattle Institute (BCI) Cattle Chat podcast.
Culling Time
“Oftentimes producers cull cows in the fall, but mid- to late-summer can be a good time of year to early preg-check those females and cull the open or short-bred ones,” said K-state veterinarian Bob Larson. Short-bred females are those that conceived late in the breeding season, according to Larson.
He said veterinarians are able to check for pregnancy status 40-50 days past conception. If they are using ultrasound technology, pregnancies can be dated at 30-35 days postconception.
“One reason to do that now is to identify the cattle that are going to leave the herd and get them off the pasture ahead of when lots of cattle will be entering the marketplace,” Larson said.
Veterinarians are able to check for pregnancy status 40-50 days past conception. If they are using ultrasound technology, pregnancies can be dated at 30-35 days postconception.
Cattle are sold by the pound, so another consideration might be to hold onto those cull cows longer and give them additional feed resources to help garner a higher selling price, said the experts.
“Producers really need to look at the economics of that decision, because in a drought situation where the cows are thin and feed costs are high, it may not make sense to hold onto those cows longer and give them additional feed,” nutritionist Phillip Lancaster said.
Herd biosecurity
Conversely, if cattle are leaving the herd, producers may also be looking to add replacement heifers and cows to the ranch at a later date. The experts say applying biosecurity measures will be key to maintaining herd health.
“Anytime there are new additions to the herd, we recommend a 15- to 30-day quarantine,” said K-State veterinarian Brian Lubbers. “This quarantine is especially important if you are bringing in outside cattle to a reproductive herd.”
The quarantine means the cattle have no nose-to-nose contact or opportunity for oral/fecal contact, Lubbers said.
While this quarantine will allow some diseases to appear if the cattle are contagious, it won’t show them all, according to Larson.
“There are some diseases that have persistent carrier states in which the animal doesn’t appear sick, but for a lot of those diseases we have good tests that we can use to identify the carriers,” Larson said.
Two of the more common diseases for persistent carriers are bovine viral diarrhea (BVD) virus and trichomoniasis, Larson said.
“Work with your veterinarian to figure out if you need to test your herd,” he said.
Lancaster also added that knowing the health status of the source herd will help the producer and veterinarian make a herd health plan for those new animals.
To get started, Larson recommended producers refer to the BVD and trichomoniasis consult apps found on the BCI website.
To hear more of this discussion, listen to the BCI Cattle Chat podcast online.
For more on culling decisions, read “Cull Cow Considerations,” in the September 2021 Angus Beef Bulletin available online at http://www.angusjournal.com/salebooks/ABB-SEP-2021/#page/68.
Editor’s note: Lisa Moser is a communications strategist for Kansas State University. Photo courtesy K-State Research and Extension.
