Maternal Behavior of Beef Cows at Parturition

Over an 11-yr period maternal behavior, calf birth weight and calf condition were recorded within 24 h for 2,684 parturitions. Maternal behavior was rated on a scale from 1 to 11, where 1 indicated extreme aggressiveness and 11 indicated no maternal attentiveness. Birth condition was rated on a scale from 1 to 9, with 9 being fattest and 1 thinnest. Respective breed means of Hereford, Angus, Charolais and Red Poll were 6.2, 5.3, 6.0, and 5.7 for maternal behavior rating; 30.6, 27.3, 39.2 and 32.6 kg for birth weight, and 5.5, 4.7, 5.6 and 5.5 for birth condition. Heritability estimates for maternal rating, birth weight and birth condition were .06 ± .01, .48 ± .02 and .19 ± .01, respectively. Genetic correlations between maternal rating and birth weight and condition were .04 ± .05 and −.02 ± .06, respectively. These results suggest that, in the population of cows studied, nongenetic influences were the primary cause of differences in aggressiveness of cows at parturition.