Va. Tech beef cattle study investigates temperament
BLACKSBURG, Va. — A two- year research project looking at the question of what impact cattle temperament can have on production rates, is nearing its end with the results scheduled to be presented at the International Ruminant Reproduction Symposium in Brazil in September.
The research was led by Dr. Vitor Mercadante, a Virginia Tech beef cattle researcher who said the report on the project will be presented in Brazil by Nicholas Dias.
Dias is working on his Master’s Degree in Mercadante’s lab and the project is part of his thesis.
“The objective of the present experiment was to assess the effects of temperament on pregnancy rates to fixed-timed artificial insemination (FTAI) in Bos taurus beef heifers,” Dias wrote in his paper.
The researchers looked at the role of stress and temperament on fertility, Mercadante added.
He said his team studied heifers at Virginia Tech and the Virginia Department of Corrections site at South Hampton.
The researchers developed a chute score sheet to measure how the heifer’s reacted to the chute and also measured how fast they exited the chute by using infra-red sensors.
Both chute score and exit velocity were then used to calculate a temperament score.
Scores ranged from one to five with cattle on the lower end being considered calm and those registering three or above as excitable.
“The biggest take home message is the difference in fixed-time artificial insemination pregnancy rates between calm and excited heifers,” Mercadante said. “Heifers with calm temperament had 55 percent pregnancy rate compared to 36 percent of excited heifers”.
In discussing the research, Mercadante noted that while farmers may not be able to do an actual exit velocity, they can easily assign chute scores and use other things to spot the heifers that have an adequate temperament and will most likely have increased fertility.
Noting how calm they remain at weaning and how they react in the chute, as well as how fast they go through a chute—the ones that remain restless in the chute and get out fast are considered temperamental — are ways to spot heifers with excitable temperament.
He also suggested using calming techniques rather than sending the replacement heifers to the back of the farm and letting them grow without handling them. Such things as bringing them closer to the barn where they will have more contact with people, feeding them — especially in cattle pens — and handling them more often can be helpful.
Some people supplement them and do little things to help the cattle feel comfortable with people like walking around the heifers while feeding, he noted.
“The little things make a difference,” he said.
Mercadante grew up in Brazil and learned about farming on his grandfather’s coffee farm.
He also became a veterinarian in his home country. He came to the United States and earned his Master’s and Doctorate degrees at the University of Florida. Mercadante joined Virginia Tech’s Department of Animal and Poultry Science in 2016.
He said he is excited about being in Blacksburg and the research projects scheduled at the Kentland in the coming years.
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