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As Ron Skinner, a veterinarian and seedstock producer near Hall, Mont., states, producers need to be careful of really small 60- to 65-pound calves.

“If we keep these as breeding stock, we may start building a body type that is not optimal for calving. Some of these will have short bodies and not enough thickness,” he explains. “We can build ourselves into a trap where heifers can’t give birth to a 90-pound calf.”

“It may not happen until 15 or 20 years down the road, but if we get into that situation, it can be a wreck. At that point, we are better off to disperse that herd and start over,” says Skinner.

It’s more common, however, for stockmen to get into trouble at the other extreme, since people tend to keep the biggest heifers as replacements, he continues.

Those beautiful, big heifers probably were large at birth, Skinner emphasizes, and as producers keep selecting this type of animal, they soon will have cows that are a frame size or two larger, along with bigger calves at birth.

“Do not keep heavy birth weight females. Even if a big heifer is the biggest one in the bunch, we’ll still have to assist her at birth. It’s just as important to watch birth weight on females as it is on the bulls we select,” he says.

When selecting a bull, Skinner notes producers need to make sure the birth weight of both the bull and his mother were moderate, rather than large. Birth weight is a heritable trait, and many of the traits a bull passes to offspring will be from his mother, as well as his sire.

His daughters especially tend to take after their paternal grandmother in many important traits, Skinner comments.

“When trying to bend the curve and have moderate birth weights and high performance, much of our success will depend on where we get our genetic seedstock. We need to know how our bull producer goes about selecting genetics and how careful he is on keeping good records. We want to be sure he is breeding for optimizing important traits,” says Skinner.

Heather Smith Thomas is a correspondent for the Wyoming Livestock Roundup. Send comments on this article to This email address is being protected from spambots. You need JavaScript enabled to view it..

Managing heifers nutritionally can be challenging for producers, and it is incredibly important for the productivity of the heifer later in life, comments an Idaho Extension specialist.

“Certainly we’ve got a lot of opportunities to influence the nutrition of heifers are various times of their lives, whether they are pre-weaning or post-weaning, but the other challenge we have is that there’s a lot of different environments in which we have to raise cows. She has to work as a cow, so that also influences how we develop those heifers,” says University of Idaho Beef Extension Specialist John Hall.

Time of pregnancy

Hall emphasizes that a pregnant heifer is not the same as an early pregnant heifer.

“There’s a significant advantage in getting those heifers pregnant early in the breeding season,” he says, citing research from the U.S. Meat Animal Research Center by Cushman, et. al. in 2013. “Those heifers that became pregnant in the first 21 days of the breeding season had greater longevity, stayed in the herd longer, produced more calves in their lifetime and produced more pounds of calf.”

“Getting those heifers to breed early in their first breeding season is the key to lifetime productivity,” Hall comments. “Certainly one of the ways we can control that is through nutrition.”

Nutritional impacts

Ensuring that heifers are pregnant early begins prior to weaning.

“The pre-weaning phase is not a phase we have a lot of control over,” Hall says. “It tends to be influenced by the milk production of the dam and the forage availability during the time of year that the calf is on its mother.”

He continues, “We do know from research that those animals that are heavier at weaning are the ones that tend to come into heat sooner and breed more effectively throughout the course of the year.”

At the end of the day, heifers that gain more from birth to weaning also tend to breed early in the breeding season.

As a result, early weaning can have positive impacts on heifers because producers have more control over the heifer’s diet at that point.

Hall notes that, after looking at several studies, heifers that are weaned between 90 and 100 days, then put on a high-concentrate or high starch diet and managed the same as their counterparts often reach puberty earlier and have higher pregnancy rates.

“That tells us that the pre-weaning phase is a critical time in the heifer’s life,” Hall says. “That nutrition that she is exposed to can affect her subsequent reproduction for the rest of her life.”

“It’s key for us, as managers, to keep track of that,” he adds.

Pre- and post-weaning

“The pre-weaning phase is a critical phase for the heifer,” Hall says. “It’s an important phase in terms of her reproductive life and one we don’t have a lot of management strategies for, but it’s certainly one we have to think more strongly about.”

However, post-weaning phases of the heifer’s life is the one that producers have control over, and it has also been studied intensively.

Looking at research, Hall says that many studies have clearly demonstrated that limiting nutrition can delay puberty, which increases the likelihood that they will have trouble getting pregnant, resulting in long-term reduction in reproductive rates.

“On the other hand, if we have a program in which rates of gain are better for heifers, we see those heifers perform well,” he explains. “These studies gave us the recommendation that heifers need to gain between 1.25 and 1.75 pounds per day from weaning until breeding to reach the proper weight.”

Feeding strategies

Another aspect that studies have looked at is the merit of feeding heifers in a big group compared to in several smaller groups by weight.

“If we split them into two separate groups and feed them according to their size, studies have shown that not only do those lightweight heifers have an advantage, but we have also grown them most appropriately for their target weight,” Hall explains.

The result, he adds, is higher pregnancy rates across the herd.

“When we have big heifers and little heifers in the pen, the big heifers get over-fed, and they get more fat,” he says, noting that, at the same time, smaller heifers are underfed.

Staggered feeding

Feeding heifers can be expensive, but Hall notes that they do not have to be fed on a steady plane from weaning until breeding.

“Can we kind of rough them through the winter when the weather is cold and it’s expensive to feed and then push them along before spring comes?” he asks. “There’s a number of different studies, but across all those studies, it didn’t matter whether it was slow, even gain or slow, then fast gain before the breeding season in a stair-step method. There’s no statistical difference between the heifers.”

As long as heifers reach their target weight, Hall says it is less important how the heifers get there.

In some fairly new data, Hall also says that there are may be advantages to using a stair-step method to feeding heifers, though the research needs to be done to confirm that research.

“From the dairy industry, we now see that the stair-step method prevents adipose tissue in the udder, so, therefore, it allows milk production to be better,” Hall comments. “There does seem to be some advantage over an even gain methodology.”

“As managers, we can use that to our advantage to decrease feed costs, increase profitability and still maintain heifer productivity,” he notes.

Hall spoke during the 2016 Applied Reproductive Strategies in Beef Cattle Workshop, held in Des Moines, Iowa on Sept. 6-7, 2016.

Saige Albert is managing editor of the Wyoming Livestock Roundup and can be reached at This email address is being protected from spambots. You need JavaScript enabled to view it..

Cull cows account for 15 to 30 percent of a cow/calf producer’s income, making their management a crucial aspect for producers to consider.

“Management of cull cows is not an insignificant aspect of a producer’s income. Each year, producers are faced with the decision to preg-check or not and this can really make an impact on the bottom line,” said Canfax Research Services Manager Brenna Grant.

In a webinar by the Beef Cattle Research Council titled “The Economics of Pregnancy Detection,” Grant discussed the impacts of the current cattle markets on the economic viability of pregnancy testing in cow/calf operations.

Cull options

There are three main options for producers to choose from when culling cows from their herd.

The first option is pregnancy checking and then culling in the fall, which is beneficial for reducing feed costs over winter.

“This has the benefits for the producer of providing cash flow and minimizing additional overhead costs associated with keeping those animals over the winter,” said Grant.

The second option producers can choose is short-term feeding. Producers pregnancy check their animals but separate the cull animals from the herd to supplement with a high energy ration for a short period of time to add weight.

“This means that they not only get a higher price when the markets are out of fall low prices, but producers also get added pounds sold,” she explained.

The final option is overwintering cattle and selling the cull cows in the spring. This option avoids pregnancy testing.

Economic factors

According to Grant, several factors influence the economics of pregnancy checking.

“The economics of preg-checking are really dependent on the cull cow market price,” she said.

Winter management strategies also influence the economic viability of pregnancy checking.

“This is really going to impact what our yardage is, as well as our feed costs,” said Grant. “That winter management system is also going to have implications on what our average daily gain is and the final weight of those animals.”

While it plays a role, Grant’s study did not find that veterinary costs were a large economic factor.

“This is one cost that’s been brought up in the literature quite a bit, but we found, when we looked at the model, it’s a really minor aspect of the equation,” she commented.


A test model was created to compare the three culling options. The purpose of the model was to determine how to maximize value.

“This whole model is really set up with the premise that, instead of minimizing cost, we want to maximize value for the producer,” explained Grant.

Grant’s research determined that cull cow body condition in the fall is a significant driver in deciding whether or not to pregnancy check.

“If they’re fat from being on grass all summer and there’s very little potential of additional weight gain over the winter, we’re maybe not going to see much benefit because we’re really only gaining that seasonal price variation,” she said.

However, if cows are thinner and have the potential to gain weight, overwintering or short-term feeding may be a more viable option.

“We’re not just going to have the additional pounds sold, we’re going to have the seasonal price increase, as well as potentially increasing quality grades,” noted Grant.

Winter management

The type of winter management system that a producer uses impacts the economic viability of pregnancy checking.

“The higher a producer’s feed and overwintering costs, the more favorable preg-checking and culling cows in the fall is,” said Grant.

She explained that costs can be offset by cow performance and will vary from operation to operation. It is important to note that even if feed costs are low, if average daily gain is minimal, it will offset some of the advantages.

Cow prices

Ultimately, cow prices are one of the largest factors in choosing a culling option. A threshold point of $1.20 per pound is important for producers to consider when making a decision.

“If prices are lower than this, it actually encourages producers to preg-check and cull in the fall,” explained Grant.

In most scenarios run in the model, short-term feeding showed the greatest economic benefit for producers.

“The only case when separating cull cows was a less favorable option is when the overhead costs of separating them and feeding them separately was very high or the number of days on feed was really low,” she said.

Current market

As cow market prices have peaked and come back down, Grant emphasized the importance of the counter-seasonal year that was observed last year.

“Last winter was the first time that were in a bear run and cow prices actually dropped from the fall going into the spring,” said Grant.

In a situation where prices are increasing, pregnancy checking does not prove to be economically viable. However, in markets that are decreasing, it becomes more economically viable to pregnancy check and cull in the fall.

“With increasing prices, preg-checking is obviously a negative option, but that’s not the case in decreasing prices when comparing overwintering or short-term feeding compared to preg-checking. Basically we’ve got declining prices to encourage preg-checking based on our economic gains,” she said.

Grant concluded that pregnancy testing is currently the most viable option for producers to consider.

“As we come back into a price situation with lower cull cow prices, preg-checking does make sense,” comments Grant.

Emilee Gibb is editor of Wyoming Livestock Roundup and can be reached at This email address is being protected from spambots. You need JavaScript enabled to view it..

As many cattle operations begin pregnancy checking their bred cows this fall, producers also have the opportunity to evaluate body condition and determine if different management strategies are needed before winter begins.

In a webinar discussing how to improve weaning weights, conception rates and calf health, Saskatchewan Regional Livestock Specialist Naomi Paley urged producers to consider the long-term impacts that body condition has on rebreeding, weaning weights of the current year’s calf crop and weaning weights of future year’s calf crops.

Fall evaluation

Ideally, Paley suggested that producers evaluate their animals hands-on and assign body condition scores at least three times per year.

“If we can at least get our hands on them once or even twice during the year, that’s a benefit, and we’re going to be able to use that information to help us be a better manager,” said Paley.

Fall is a convenient and important time to evaluate body condition, continued Paley.

“The fall time is a good time to evaluate body condition, when we’re processing cattle or running them through the chutes. In the fall, we really want to have those cows in good shape,” she said.

Feed costs

Paley advised producers to consider feed costs when looking at maintaining or adding weight to an animal.

“It’s more expensive to put weight on a cow during the winter than it is to maintain her in good condition,” she said. “Our feed costs are higher for that cow if we’re trying to put condition on her during the winter, and it’s also biologically expensive.”

An average 1,350-pound cow needs to gain 200 pounds of fat to increase one full body condition score.

Adding 200 pounds would equate to 25 bushels of barley or 2,000 pounds of high-quality hay.

“There’s definitely a feed cost associated with trying to put body condition back on to a cow and get caught back up to where she needs to be to have a healthy calf and rebreed in a timely manner,” continued Paley.


“There are those who think that burning body condition or burning some backfat off of the cow is a good way to try and make use of extra reserves that the cow has and that they can sort of bank on that,” said Paley.

However, she noted, “There are some biological costs associated with that.”

A cow receives approximately 900 megacalories of energy for every unit of body condition that is lost. Alternatively, it takes about 1,200 megacalories of energy for the cow to gain one unit of condition.

The extra biological cost of gaining weight back results in a loss of efficiency of approximately 50 percent, explained Paley.

“We can see that it’s a really inefficient system, and it’s going to end up costing us in the end one way or another when we’re counting on sort of farming the fat off of the back,” she said.

Growth and health

During calving and lactation, cow body condition has a significant impact on calf health and growth.

Cows that are below desirable body condition at calving or losing condition after calving may have a five to 25 percent reduction in calf weaning weight, said Paley.

“This is largely due to the reduced nutritional value of the cow’s milk and the amount of nutrition the calf is receiving during the nursing period,” she continued.

Because of the reduced nutritional value of the milk, the calf’s immunity will be suppressed. Reduced immunity combined with reduced weight gain because of lower milk production can ultimately lead to lower weaning weights, Paley explained.


Body condition at calving and throughout lactation is important for timely rebreeding, said Paley.

“Contrary to some management systems, the goal is not simply to get our cows bred. We want them bred early,” she emphasized.

Every time a cow misses a cycle or doesn’t become pregnant has a direct impact on weaning weight of the calf.

“Every time a cow misses a cycle or doesn’t get bred on a cycle, she remains open, so the calf is 20 days younger,” said Paley. “If our calves usually gain about two pounds a day, it’s 40 pounds lighter, which can account for a $90 per head loss every time a cow skips a cycle and doesn’t get bred.”

Emilee Gibb is editor of Wyoming Livestock Roundup and can be reached at This email address is being protected from spambots. You need JavaScript enabled to view it..

Kansas State University Veterinarian Bob Larson says, “If my cows are working and my bulls are working, if we run into a disease that kills pregnancies, that will kill our momentum, as well.”

Live calves bring revenue to the farm and ranch, and he notes that diseases like infectious bovine rhinotracheitis (IBR) and bovine viral diarrhea can cause abortions and decrease profits for producers.

“IBR and BVD are two of the most common causes of abortion that we deal with,” Larson comments. “The good news is, we have effective vaccines for both of those diseases.”


“IBR is a herpes virus,” Larson says. “That means it is a really common disease, and it is secreted by any fluids. It is easily passed from one cow to the next.”

IBR also results in a lifelong infection in the animal. Infected animals will likely exhibit symptoms, such as a cough or runny eyes, the first time they are exposed. However, from that point forward, they will shed the virus during times of stress.

“They stop shedding the virus until they get stressed,” Larson explains. “If they get stressed during calving, while being moved or whatever, she’ll shed the virus and spread it around for a while.”

In feedlots, the disease is often called red nose.

“It is a really, really common virus,” Larson emphasizes.


While IBR is common, Larson notes that is can be a challenge because it presents mildly in adult cattle.

“They don’t get sick,” he says. “The calves go through it and get runny eye, and abortions don’t happen. They wait about two months.”

He also notes that signs in cows are very subtle.

“We may not see any signs or if we notice problems, we don’t think about them until two months later when the cows start slipping calves,” he says. “This is one of the problems. IBR causes problems.”

Larson further mentions that IBR is one of the major causes of abortion in the U.S. during the last half of gestation.

For producers who start seeing abortions and then remember having runny-eyed calves from the previous year, Larson says, “That makes me suspicious we have IBR.”

Necropsy and sending samples to the lab will confirm the disease.


Larson also notes, however, that vaccines for IBR and prevalent and effective.

“I like to give two modified live vaccines at weaning and breeding to try to set up some good immunity prior to the first breeding season,” he says. “Technically we shouldn’t need more than one, but there is value in making sure as many heifers respond as well as possible.”

He also notes that he prefers to vaccinate replacement heifers at the start of breeding and at preg-check time.

“I have a lot of tips, and I booster my cows once a year,” he says. “Producers should talk to their vet about their preference.”

He adds, “The one concern is that if I give a modified live vaccine to a pregnant cow that is naïve, I can abort her with the vaccine. However, most cows get vaccine or are naturally exposed, so a booster is not enough to cause them to abort.”

“They do need to be well vaccinated before they get pregnant,” Larson says.


“BVD is somewhat similar to IBR in that is it really common, but while there are a lot of cows persistently infected with IBR, only a very few calves carry the BVD virus,” Larson explains, noting that only four to six BVD persistently infected (PI) calves are expected for every 1,000 head that enter the feedlot. “The problem is, if cows aren’t spread out, a couple PI calves can come into contact with a lot of cows.”

He adds, that PI calves shed the BVD virus continually throughout their life, rather than only during times of stress, like with IBR.

“It doesn’t take much contact to get BVD,” he adds.

“If a cow is exposed to the virus during the first half of her pregnancy, one of two things will happen,” Larson says. “Either she’ll abort – and a lot of time she does, but if she doesn’t, the calf will get infected with BVD. If he survives, he will become PI with the virus.”

The source of the BVD virus is nearly always a PI calf. While some PI calves are poor-doing, others look healthy and stay in the herd.

“Our best estimate is about half of the PI calves die between birth and weaning,” he says. “Another half die between weaning and yearling age.”

Often BVD PI calves don’t make it to their first calf.

“It’s a common problem,” Larson says. “If she survives to have her first calf, it will always be a PI calf.”

With BVD, Larson says, “Pregnant cows exposed to BVD will either abort or create new PI calves for next year.”


While vaccines for BVD are available, Larson notes that no vaccine is perfect.

“If they were perfect, we wouldn’t talk about this disease,” he says. “However, if people have an abortion storm, I get to investigate it, and in all my years of looking at problems we trace back to BVD, they are almost always unvaccinated or poorly vaccinated herds.”

He also notes that it is important to follow vaccine protocols and to have a consistent program.

“If we only vaccinate some years or we don’t vaccinate at all, the immunity isn’t the same,” he says.

“Viral diseases are bad,” Larson comments. “They will always cause us some problems, but we have tools that make disease control possible.”

Larson spoke during a producer dinner in early March in Gillette. Boehringer Ingelheim Vetmedica sponsored the dinner.

Saige Albert is managing editor of the Wyoming Livestock Roundup and can be reached at This email address is being protected from spambots. You need JavaScript enabled to view it..