Select for temperament by the whites in their eyes

 Cows are known for their big, beautiful dark eyes. But University of Guelph researchers have discovered it's actually the whites of their eyes that are important when it comes to determining their temperament reports The Beef site. Their study, published in the recent online issue of the Journal of Animal Science, found that the higher the proportion of visible white in a cow's eye, the more anxious the animal. "Cows whose eyes were about 50-per-cent white were very anxious," said Sarah Core, a master's student who worked on the study with Guelph animal and poultry science professors Steve Miller, Tina Widowski and Georgia Mason. "The more passive cows had about 20-per-cent visible white in their eyes." Anxious cattle can be dangerous and frustrating to handle and can also reduce profits and productivity because they tend to have lower weight gain and poorer meat quality, said Core. They're also more likely to injure themselves or other cattle. As a result, identifying well-mannered cows is important when it comes to breeding. "With growing consumer demands for higher-quality products and animal welfare, selection for docility in cattle and other behavioural traits is beginning to play a key role in increasing profits throughout the beef industry," she said. The study included 140 beef cattle. Researchers had the cattle enter a chute where their head was restrained. They then collected video images of each cow's response and compared it with the amount of white visible in their eyes. "There was a significant positive correlation," said Core. "The cows with a large proportion of white in their eyes would respond by jumping and thrashing around, and the cows with a smaller proportion of white in their eyes would just stand there."