Individual differences in calf defence patterns in Red Angus beef cows

Abstract

The objective of this study was to evaluate differences in individual calf defence behaviour patterns and maternal protective behaviour of beef cows 24h after calving. A single herd was observed on an extensive ranch in Colorado, USA. A total of 341 cow–calf pairs (95% Red Angus and 5% Angus×Hereford commercial crossbreds) were used. Each cow–calf pair was approached with an unfamiliar utility vehicle that circled the pair and gradually decreased the distance between the vehicle and the pair. The following four distance measurements were taken with a digital range finder to evaluate maternal protectiveness: (1) the first time the cow raised her head and oriented towards the vehicle; (2) when the cow placed herself between her calf and the vehicle or lowered her head; (3) when the cow vocalised; and (4) closest distance the vehicle approached the cow–calf pair. Calf defence behaviour patterns were recorded as yes/no-classifications and were: (1) protection: the cow positioned herself between the vehicle and her calf; (2) aggression: the cow lowered her head; and (3) the cow vocalised. Hair whorl patterns (HW) on the forehead of each cow were used as a measure of individual differences in temperament. HW pattern and age were collected when the cows were in a squeeze chute during routine handling. HW pattern was classified into the following groups: high, middle, low, abnormal, multiple HWs or no HW. Ninety-nine percent of the cows moved between the vehicle and their calf to protect it, 13.2% lowered their heads as a sign of aggression and 78% vocalised. Cows with high HW or multiple HW oriented towards the vehicle at a further distance, compared to cows in other HW groups (P<0.05). Cows with a high HW vocalised at a further distance than cows in other groups. Younger cows (3years) were approached more closely with no behavioural changes than older (5years) cows (P<0.05). The results suggest that cows with a high HW and older cows may be more vigilant of their surroundings.