US - Flighty cows and heifers could be costing ranches money by staying open, cow/calf producers in Oklahoma have been warned.
Studies at the University of Florida have added to a growing body of research linking unruly cattle behaviour, blood cortisol levels and decreased reproduction success.
Furthermore, stress has a more pronounced effect on Brahman influenced cattle, of particular concern in regions of the US, such as Florida, where Brahman genetics have a big influence on state herds.
“The wildest cows are the least likely to become pregnant,” said Oklahoma State University cow/calf expert, Dr Glenn Selk.
“The bottom line is that there is a direct correlation between temperament score, blood cortisol levels and reproduction.”
In a review of the Florida research, Dr Selk laid out how wild cattle can be identified objectively and suggested Oklahoma cattlemen use scoring systems to assist culling decisions.
“A temperament score of one to five can be assigned to cattle restrained and leaving the cattle chute and also in the pen, with one denoting a very calm exit and five involving running and kicking,” said Dr Selk.
He explained that cattle with high temperament scores correlated to high blood levels of the hormone cortisol, a widely acknowledged indicator of stress.
“Physiologists call it the ‘fight of flight’ hormone,” said Dr Selk. “It gets very high in blood when mammals become excited.”
Not only is an unruly cow a danger to ranch hands and ranch equipment, but by staying open and not outputting the desired one calf per year she is hurting farm profits, concluded Dr Selk.
The Florida trials took two herds of Braford/Brahman and Angus - one of 40 and another of 400 – from 2006 to 2007. The researchers ran acclimation tests within the experiment.
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