Individual differences in docility in Limousin cattle1

Docility tests were performed over 3 yr on 906 Limousin heifers sired by 34 males. The heifers were tested individually when they were 10 to 11 mo old in a pen with a handler who had 2 min to lead the animal to a corner, keep it there for 30 consecutive seconds, and then to stroke it. Behaviours of the animals were recorded and scores calculated. The first score (docility score) was a continuous variable combining the greatest possible information. The second score (docility criterion) was a categorical trait with four classes. Tests were performed by seven different handlers. The effects of handler, year, birth period, dam parity, birth region, husbandry system, and sire were estimated. Handlers, birth period, husbandry system, and sire had significant effects. In particular, animals that were managed indoors were more docile than those reared out-of-doors at least part of the time. Heritability estimates of the docility score (.22) and docility criterion (.18) seem sufficient to select for docility traits.