Weaning and pregnancy checking have been the major events at many commercial cow-calf herds over the last few months.
As part of that process, many producers have to make decisions about which cows should be offered the early retirement option. This year many herd managers are also struggling with limited feed resources because of drought conditions, which makes some of these culling decisions even more critical. Difficult decisions have to be made regarding which cows to keep and which cows to cull. Longevity in cows is not a trait that we talk about a great deal, but it is an important trait in economic terms. Raising heifers is expensive and if we need fewer replacement heifers, we end up with more calves to sell.
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Longevity is a moderately heritable trait and if we can end up with more calves per cow’s lifetime, it will usually mean more dollars in our pocket.
About 15 percent of cows are usually replaced yearly in most cow herds. The most common reason for leaving the herd is because of reproductive failure.
Of the beef cows culled, about half of them didn’t get pregnant within the prescribed breeding period.
Cows that don’t get pregnant are often in poor body condition at breeding time. In many herds the cows that are supposed to be pregnant with their second calf (last year’s first calvers) are often the ones most commonly found open.
When heifers calve for the first time, they typically take longer to come back into heat than older cows. This means that if the heifers are calving at the same time as the rest of the herd, a higher percentage of them will not get pregnant in the next breeding period and will show up as open cows.
It is extremely important to give heifers a head start on the rest of the herd to allow them that extra time to come back into heat after they calve. However, this does mean a longer calving season, which is a potential negative tradeoff.
First-calf heifers also have higher nutritional demands because they are still growing as well as raising a calf for the first time. They may need increased nutrients so that they don’t make an early exit from the herd due to poor body condition, which results in a failure to come into heat and get pregnant.
About another quarter of all the cows we cull leave the herd because of calving problems or calf survival issues.
Most producers are doing an excellent job of reducing the losses of calves at calving due to calving problems. Many veterinarians report that they are doing fewer calvings and caesarean sections every year, and much of that reduction is because of better management and ensuring that we are using easy-calving and low birth-weight sires in our cow-calf herds.
However, we also need to pay attention to mothering ability and temperament in our cows when making choices about which one to keep in our herd. Making sure that each cow raises its calf through to weaning is a vitally important economic trait.
Mismothering of calves can be a frustrating problem at calving time, and these cows will often continue to be a problem in future years. Calves that are mismothered are less likely to get up and suck right away and often don’t receive adequate colostrum.
Even if the calf is successfully fostered onto another cow, in many cases these calves are more likely to get sick and die. Cows that have poor mothering ability can be a major detriment to a calf crop percentage and should definitely have a major strike against them when it comes to making culling decisions.
The last 25 percent of the cows that leave the herd often do so because of physical reasons such as lameness, udder problems and other diseases.
Udder conformation is another important trait for calf survival. Pendulous teats and teats with blind quarters make it very difficult for newborn calves to suck and receive adequate colostrum.
It’s important to note these cows at calving time and place them on the culling list. We often don’t notice their udder conformation by the time weaning time comes around, and we can easily forget about the cow that has a dry quarter or pendulous teats.
Cows with less than four functional teats will usually produce less milk, which will have a detrimental effect on the weaning weight of their calves.
Lameness is another common cause of culling in older cows, and by selecting heifers and bulls with good conformation of feet and legs, we can prevent some of the premature culling that may occur in our herds.
Most of the culling reasons that we’ve discussed would be classified as non-voluntary culling. We have to cull these cows because they have significant problems that affect their production. Having a cow that is not pregnant is certainly a major cause of poor productivity.
Ideally, we would like to leave some room for voluntary culling for other performance traits such as calf growth and conformation. However, if our reproductive management is not ideal, there is often no room left for culling for poor weaning weights and genetics. It is really through voluntary culling that we can make our most significant gains in the genetics of our cow herd.
All too commonly, when we do make voluntary culling decisions, the decisions are made with inadequate data. Using herd data such as birth dates, weaning weights and cow lifetime histories provides us with the ability to make much more intelligent culling decisions. Producers should talk to their veterinarian about the options for cow-calf software programs that will help them make these culling decisions. Having the ability to link the productivity of our cows with weaning weights, post-weaning performance and carcass data will allow cow-calf producers to make huge gains in productivity through genetic selection and intelligent culling.Culling decisions in the cow herd difficult but important.
