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Breeding loss increases cost

by Wyoming Livestock Roundup

In any cow/calf operation, a rancher’s primary goal is to get a live calf on the ground, preferably towards the beginning of the calving season. When this doesn’t happen, it may be time to pinpoint the problem, according to Richard Randle, beef extension veterinarian with the University of Nebraska. 

“The primary goal in any cow/calf operation is to get a high number of cows pregnant in a timely manner,” Randle said. 

If producers are starting to see too many open cows, late calving cows and a strung out breeding season without an explanation, they may need to study their breeding program more closely to determine the cause. 

Diagnosing the problem

“The producer may also need to work with a veterinarian to determine what is happening,” Randle continued. 

They will need to provide the veterinarian with information about their vaccination history, any herd additions or co-mingling, nutrition and feeding history, heifer development, the first calf heifer program, bull battery and the environment. 

“I like to ask ranchers lots of questions to gather data to start looking at these problems,” he explained. “Even if a producer has this information, troubleshooting reproductive issues can still be difficult.”

“Many times reproductive problems aren’t recognized until after the fact. It could be weeks or months between the inciting cause and recognition of the problem,” he explained. “At that point, diagnostic tests aren’t very helpful, and you usually can’t alter the course of the problem.” 

The best samples to diagnose the problem are aborted fetuses or placentas. 

“The problem is they are hard to find when they are fresh,” he said. “You usually find them when they are days to weeks old, but you really need to find them when they are only hours old. It is hard to find samples that are meaningful.”

He also cautioned producers that just because an organism is identified, doesn’t necessarily mean it’s the cause of the problem. 

Randle likes to work with paired samples. 

“I like to sample a number of affected cattle today and again in four weeks. Then, I look at if there is a change. It helps to have many samples to work with instead of just one or two,” he said. 

“What makes this difficult is this all costs money and takes time,” he continued. “But, our goal is to try and obtain answers to help the rancher move forward. Unfortunately, only 10 to 30 percent of the cases involving reproductive issues ever have a confirmed cause or causes.”

Big picture

When diagnosing reproductive issues, Randle said it is important to look at the big picture to find a starting point. 

One area of particular concern is a producer’s mineral and vitamin program. 

“We recognize there is a role of many vitamins and minerals in reproductive management,” he said. 

The most important vitamins and minerals to look at are copper, selenium, cobalt, manganese, iodine, phosphorus, molybdenum and vitamin E. 

Vitamins and minerals can have complex interactions with one another. 

“If there was a feeding problem during the winter and we are trying to diagnose a reproductive problem in the spring, the feed is gone so there is no way to evaluate whether or not it was the problem,” he explained. “If there was a copper problem, for instance, and you corrected it 45 days later, there is no residual effect to know if it was the cause.”

Protecting your herd

“Based on all this information, how do you protect yourself to reduce risk and minimize impact of a potential reproductive issue?” Randle asked. 

Ranchers should develop a sound reproductive management strategy, which includes maintaining a proper health program, performing a breeding soundness exam on all bulls, avoiding co-mingling, maintaining a short breeding season, performing a timely pregnancy diagnosis to determine something that could be a problem early on, maintaining and managing the cattle by breeding groups and maintaining good records.

Breeding soundness

All bulls that will be used during the breeding season need to undergo a breeding soundness exam at least 60 days prior to the breeding season. 

“If one bull is bad, it will give a producer an opportunity to either recheck the bull or find another bull so he doesn’t run short on bull power during the breeding season,” Randle explained. “Studies indicate as many as 15 to 20 percent of bulls tested for breeding soundness do not meet the minimum requirements. When observed for mating ability, an additional percentage fails to perform at expected levels for good reproductive performance.”

During a breeding soundness exam, bulls are checked for testicle size, mobility of sperm and the testicles are palpated and checked for any damage. 

“It is important that a breeding soundness exam is performed every year on the bulls,” Randle pointed out. “Things can change.”

Avoid co-mingling

Another factor in maintaining a good reproductive herd is to avoid co-mingling of animals. It is best to maintain a closed herd, Randle said, but if animals are brought into the herd, make sure they come from reputable sources. 

“It is best to bring in virgin animals,” he said.

Producers also need to maintain good fences for their cattle and keep breeding pastures away from periphery. 

“If cattle are co-mingled with a neighbor, remove them promptly and know where those animals go,” he said.

Preg check early

Randle also urged producers to pregnancy check the cows as early as possible when more options are available. 

Ranchers should also stage pregnancies. For instance, know how many cows became pregnant in the first 20 days, second 20 days, third 20 days, fourth 20 days and the number of opens. This will help determine early embryonic losses and pinpoint any other reproductive issues, like disease or bull injuries, which could lead to later calving or open cows, he said. 

Randle also felt it is important for producers to manage their cows by breeding groups, rather than an overall unit. 

For instance, an operation may have a 90 percent overall pregnancy rate, but by looking at individual pastures, a producer may find four pastures with over a 90 percent conception rate, while a fifth pasture may only have a 65 percent conception rate. 

A producer should look more closely at the pasture with only a 65 percent pregnancy rate to determine what the problem is. 

“If you find the problem early, you might also be able to contain it before it spreads to all the herd,” Randle said. 

Herd immunity


“Producers should develop a herd that is highly protected against anything that might come in,” Richard Randle, beef extension veterinarian with the University of Nebraska, said. “It is important for producers to use the appropriate products at the appropriate times in order to achieve this.”

A sound vaccination program also needs to be developed focusing on the young stock – replacement heifers and younga bulls. 

“Compare your replacement heifers and young bulls to children. When children start school, they have health records to show they have had the appropriate vaccinations to move into the main population. Producers need to do the same with their replacement heifers and young bulls,” Randle explained.

For replacement heifers, producers should also focus on vaccinating against reproductive diseases like the viral diseases IBR and BVD and bacterial diseases like Leptospirosis and Vibriosis. 

“Replacement animals should receive two to three vaccinations against reproductive diseases from weaning to breeding,” he continued. “A similar vaccination program should be in place for young bulls.”

For adult animals, Randle also recommends producers focus on the same four reproductive diseases – IBR, BVD, Leptospirosis and Vibriosis. 

Cattle should be vaccinated for all four diseases prior to breeding and for Leptospirosis during mid-pregnancy. 

Gayle Smith is a correspondent for the Wyoming Livestock Roundup. Send comments on this article to

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