There is always that one female. The one who, when all the other females are at the feed trough, is darting in and out. You enter the pen, and she is the first to flee. Some farmers and ranchers refer to them as high-strung, excitable or fast. But research suggests they should simply be called costly.

Justin Sexten, director of supply development for Certified Angus Beef, addressed the issue of selecting for temperament his recent “On Target” column in Angus Beef Bulletin Extra. He says cattle producers often considered it to be a “convenience” trait.

When looking at replacement heifers cattle producers study pedigrees, pictures, performance data and even videos to develop a list of prospective heifers. After analyzing all of the information, often it comes down to attitude. Sexten says the final trait is one that affects overall performance and profitability.

Sexton points to recent work at Texas A&M University on how disposition affects performance throughout the heifer's life cycle.

Fast research
Researchers sorted heifers from the same ranch into excitable and calm groups based on exit speed from the chute after processing. The sort produced a group of “fast,” or excitable, heifers. Cattle in this experiment were fed in the same pens, so performance was comparable between these groups within the same environment.

The research found that excitable heifers were 72 pounds lighter entering the feedyard. Sexten suggests pre-weaning performance was reduced. “That says herd operators at all stages along the production chain could realize benefits from selecting for docile cattle,” he adds.

Calm heifers had heavier feedyard entry weights and gained faster — 12% faster during the growing period. “That brought with it an 8% greater feed intake,” Sexten says, “but feed efficiency still favored the calm heifers.”

Sexten says feed efficiency was not the biggest surprise of the study. “How these groups behaved during the feeding period offers new insights.”

Texas A&M researchers observed excitable heifers bellying up to the bunk as often as their calm pen-mates, but slowly. They spent three minutes less time eating. “That could be linked to a greater flight response,” Sexten says. “The study did not get into that aspect, but we can imagine how the excitable set would challenge the best feedyard cowboy to accurately evaluate their health status.” Based on performance results, the researchers suggested the use of disposition as a sorting tool.

Many of the cattle in the study were Bos indicus-influenced, but performance and behavior results were consistent across breeds. “That tells us the excitable, ‘fast’ calves of each breed represented were slower-gaining and less efficient,” Sexten adds.

The Texas data suggest the bottom 15% of all operations, on average and regardless of breed, may contain relatively “excitable” cattle. Sexten says further evaluation should measure the threshold for “slow enough.” “We all know cattle that are faster than seems ideal,” he says, “but the acceptable range of exit speed or excitability within a herd or group remains undefined.”

Food-chain losses
Texas A&M researchers found performance results went beyond the feedyard and into the beef supply chain.

Calm heifers had more valuable carcasses because they weighed 24 pounds more; they also had larger rib-eyes and 8 percentage points more grading Choice, Sexten reports. “Tenderness didn't directly contribute to the $56 carcass value advantage of calm heifers, but they did yield more tender steaks across the aging groups of one, seven and 14 days following harvest,” he adds.

“This look at the heifer side makes us think about the traditionally built-in option for a pen of growing heifers,” Sexten says. “On decision day, we can keep the calm ones with better breeding and performance, but we must keep in mind that the other half probably won’t perform as well for anyone on down the supply chain.”

So can heifers be too “fast” for your operation? It is something Sexten says should be considered. High-strung, excitable or fast heifers may need to be culled.

“Keep whittling off the bottom 10% to 15% of the fast ones that may be slowly eroding profitability and consumer demand for the whole beef community,” Sexten says.