Selecting cattle to breed for temperament may soon become as easy as seeing the whites of their eyes.
In a study outlined Monday in an Ontario ag ministry newsletter for beef producers, University of Guelph researcher and master’s student Sarah Core explored the correlation between the amount of white showing in cattle’s eyes and the other markers for ill temper when the animals are put through a chute.
Observers can score animals for temperament on a one-to-five scale while watching their behaviour in a handling chute, Core wrote, as long as it’s the same observer viewing and ranking all the cattle in a sample group.
The second marker is to time the animal for the speed at which it exits the chute, which “may be a good predictor of temperament,” Core wrote, as long as there are not any changes in the surroundings, such as extra animals around the exit pen or sudden noises that may cause some animals to react in ways out of character for them.
Thirdly, stress and anxiety in animals at rest may be measured by testing their blood levels of cortisol (similar to adrenaline in people), although testing for that hormone can result in highly inaccurate evaluations of temperament because it’s tough to collect blood samples without causing stress to the animal.
But a U of Guelph graduate research project at the Elora Beef Research Station measured such animals in the chute for the percentage of visible eye white, using stored images from digital video cameras.
The project found a “significant positive correlation” between eye white percentage visible and the one-to-five temperament scores as well as the animal’s speed of flight out of the chute.
“Since this measurement is reliable and highly correlated with temperament, percent eye white is a good tool for identifying animals that should be implemented in intensive selection programs for temperament,” Core wrote.
Cattle breeders have previously used other ranking systems to help improve calm temperament in a breed, Core said, citing the example of Limousin breeders who developed a temperament scoring system to rank animals with expected progeny differences (EPDs) for docility.
The average EPD for docility in Limousin bulls in 2005 sat at plus 12, Core wrote, while in 1990 that same EPD was only plus one.
“Through these intensive selection programs, it is estimated that Limousin breeders have increased the percent of docile animals by 16 per cent in 10 years,” Core wrote. “These breeders have shown that it is possible to improve temperament efficiently and that docility should become an industry breeding focus.”