Disposition has Effect Gate-to-plate
Temperament, acclimation to handling affect fertility, production efficiency and carcass quality.
BILOXI, Miss. (June 9, 2015) — Temperament isn’t always a trait considered when selecting a herd bull or replacement heifers, but Reinaldo Cooke of Oregon State University told attendees of the 2015 Beef Improvement Federation (BIF) Annual Convention that it is worth taking into consideration.
“You can make a calm cow an aggressive one; you can make an aggressive one into the devil,” Reinaldo Cooke said. “The handling can increase levels of cortisol and have significant impacts on pregnancy rates.”
Temperament, also referred to as docility or disposition, is a highly heritable trait that can ruin a producer’s day, but Cooke emphasized it could also have an impact on the pocketbook. In his research on both Bos indicus and Bos taurus cattle, Cooke found that animals with what he categorized as an “excitable” temperament are actually less efficient than cattle with an “adequate” temperament.
The reason for this is cortisol, a stress hormone that is released when the animal responds to human handling or other events in fear, he explained. Elevated cortisol levels can inhibit metabolic processes, delay puberty and postpone ovulation.
In a study of Braford cattle, Cooke shared, there was an 8% difference in pregnancy rates between animals that had lower cortisol levels compared to more excitable cows with higher cortisol levels.
Effects of stress from temperament and reaction to handling extend to the feedlot, as well. In research of Braford calves, animals with higher cortisol levels had the same average daily gain (ADG) as the calmer calves, but significantly lower hot carcass weight (HCW) and meat quality leading to a $30 value difference between the two temperament groups, Cooke reported.
He explained that there are several factors that affect the temperament of cattle. Female and younger animals can be expected to have a slightly more excitable temperament due to added hormones and, for young cattle, the lack of human handling. Breed type can play a role in temperament. Bos indicus cattle are more temperamental than Bos taurus. The type of production system can also be a factor since cattle in some operations can spend months on rangeland with no human interaction.
Temperament is both a heritable and a learned trait, Cooke reminded the audience.
“You can make a calm cow an aggressive one; you can make an aggressive one into the devil,” he said. “The handling can increase levels of cortisol and have significant impacts on pregnancy rates.”
Cooke’s research revealed that both natural temperament and attempts to help cattle learn improved temperament. He found that animals handled frequently and gently at a young age, acclimating them to human handling, can learn that the chute and processing are not things to be feared. Reducing the natural stress of being around humans resulted in decreased cortisol levels.
Cooke concluded that excitable temperament is detrimental to overall productivity of the cow herd as it can affect pregnancy rates, feedlot performance and more. He recommended selecting animals of moderate disposition to maintain their safety in the pasture and competitiveness at the feedbunk but culling the animals that cause problems because those issues extend far beyond the processing chute.
The 2015 BIF Annual Convention was hosted by Mississippi State University and the Mississippi Extension Service June 9-12 at the Beau Rivage Casino and Hotel in Biloxi. The Angus Journal and LiveAuctions.tv provide comprehensive online coverage of the event at www.BIFconference.com. Visit the Newsroom for summaries, proceedings, PowerPoints and audio of the sessions; the Awards page for announcements of award winners; and the Photos page for photo galleries of the tour stops.
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