Are cows that consistently enter the same side of a two-sided milking parlour more fearful of novel situations or more competitive?

Abstract

Two groups of 12 dairy cows were identified from a group of 70 cows according to the consistency with which they voluntarily entered one of two sides of a milking parlour during 25 milkings. The mean proportion for high consistency (HC) cows was 91% (range 86–97%), and for the low consistency (LC) cows was 60% (range 50–71%). We examined whether this characteristic related to their behaviour in a novel environment or to their ability to gain food in a competitive environment. The cows were observed in the novel environment, an empty pen near the parlour, for 15 min after milking. They were then subjected to a paired food-competition test, in which a particular cow was introduced to the pen and they were provided with a bucket of feed. This lasted for a maximum of 15 min or until the two cows stopped interacting or feeding. In the empty pen test, HC cows spent longer standing motionless (mean 665 s) than LC cows (mean 521 s) ( P=0.02), which may indicate increased fear. However, the time spent sniffing the pen and the number of steps and vocalisations was similar for the HC and LC cows ( P>0.10). In the food-competition test, HC cows took less time to start feeding (70 s) than LC cows (137 s) ( P=0.04) and spent considerably more time in control of the food bucket (HC 151 s, LC 19 s) ( P=0.01). They also instigated more aggressive interactions (C 3.4, IC 0.6) ( P=0.05) and tended to push the other cow more times (HC 2.8, LC 0.5) ( P=0.06). HC cows stood inactive for longer (222 s) than LC cows (373 s) ( P=0.04). Thus there was some evidence that cows consistently entering one side of the parlour were more fearful in novel situations, but substantial evidence that they were more dominant over other cows in gaining access to resources.