Awareness of ‘average trends’ can help with cow culling decisions

Monday, November 30, 2015

Making culling decisions for the cow-calf herd sometimes seems to require a crystal ball to see into the future, but one way cattle producers can hedge their bets is to be aware of “average trends.”

Glenn Selk, Oklahoma State University Cooperative Extension emeritus animal scientist, said producers are typically faced with many questions: At what age is she going to become less productive, start to have problems keeping enough body condition through the winter to rebreed into next year or experience mouth problems that can negatively affect her nutritionally in terms of harvesting forage?

“Obviously there is no one set rule to determine when a cow is culled, but understanding average trends can serve as guidelines and help cow-calf producers cull the herd in a timely and effective manner,” he said.

To make matters more challenging, there is great variability in the longevity of beef cows. Fortunately, records kept by a large ranching operation in Florida in the 1980s and published in the 33rd Annual Proceedings of the Beef Cattle Short Course by the University of Florida Animal Science Department, show how productivity changes over the life of the beef cows.

“These records have provided the cattle industry with large data sets – 19,500 cows and 14,000 cows in two separate years – to compare the average percentage of cows determined to be pregnant based on their age in years,” he said.

The data indicates cows are consistent in the rebreeding performance through about eight years of age. A small decline was noted as cows aged from eight to 10 years of age, with the most consistent decline in reproductive performance being noted after cows were 10 years of age.

“A steeper decline in reproductive performance was found as they became 12 years of age,” Selk said. “In other words, start to watch for reasons to cull a cow at about eight years of age. By the time she is 10 years old, examine her very closely and consider culling. As she reaches 12 years of age, plan to cull her before she gets health problems or is in very poor body condition.”

Oklahoma ranks as the nation’s third-leading producer of beef cows, according to National Agricultural Statistics Service data.