What may be already be recognized by most dairy farmers has now been put to the scientific test by a Dutch zoologist at the University of Groningen. Studying black and white Holstein Friesian cows as they developed from calf to cow, Kees van Reenen put together a group of traits he called 'temperament' and followed the traits to see the effects of their impact on the animals' health. But, it is important to note that in this study, 'health' is defined by how much milk each cow produces.
Cow traits followed included fear responses, lowing (vocalizations), stamping, pulse, and the release of cortisol. Fear responses were measured by isolating each cow from the herd for a short time and introducing her to a jerry can on a pulley. It was found that cows who examined the jerry cans for the longest period of time were less likely to produce cortisol than those who stayed away from the can.
Lowing was not shown to be a fear induced behavior; rather, it was found to be a social behavior signaling their desire to be with other cows, and it was found that cows who mooed, Interestingly, the cows who mooed most frequently also produced the most milk. suggesting, the researcher interpreted, that cows should be kept with other cows or animals during stressful situations, like when being milked.
Van Reenen administered the sedative drug Brotizolam to the cows during the test to see if their behaviors would change. As expected, their fear levels were lowered, but temperamental traits like lowing did not change. The question, then, Van Reenen put forward, was if dairy cows could be bred with temperament as a selective trait, just like good bone structure and other physical traits. (via)
That's my moo for the day!