Is gentling by people rewarding for beef calves?

Abstract

Petting and brushing, when used in experiments with animals, is often described as a positive contact or `gentling'; this classification is based on human perception, and fails to consider the animal's perception of such contacts. This experiment investigated suckling calves' perception of such contacts with humans by measuring their behaviour towards a familiar stockperson. A total of 41 beef calves were reared with twice daily sucklings under human control. At 1.5 months, they were allocated to one of three treatments. For 5 min a day, 5 days a week for 2 weeks they were socially isolated (treatment IS, n=13), or with a stationary stockman who brushed the calf when it approached (treatment PR, n=14) or with a stockman approaching and brushing the calf (treatment BR, n=14). All of the BR calves accepted brushing easily within 5 days of treatment. All of the PR calves briefly interacted with the stockman within 3 days, but by the end of the treatment, none were interacting with the stockman. Two tests were performed on 2 consecutive days after the end of the treatments and 1 month later, in the familiar environment of the treatment procedures. The test procedure included social isolation (1 min), isolation with the stationary stockman (1.5 min) and isolation with the stockman trying to stroke the calf (1.5 min). Few animals approached within 2 m of the stockman during the tests and BR calves tended to stay more than 4 m away from him ( P=0.1). Just after the treatment period, BR animals allowed more stroking by the stockman ( P<0.01) on the 2 days of tests and were more motionless ( P<0.01) on the first day of testing than animals from the two other treatments. On the second day of testing, both BR and PR calves were more motionless ( P<0.01) than IS animals. However, all the animals appeared more tolerant 1 month later and no significant difference was found at this age. Acceptance of contact such as brushing or stroking appears to be more the result of a habituation process than one of positive reinforcement.