Skinner: Consider birthweight of parents, grandparents is important for maintaining calving ease

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 roundup@wylr.net.