Milk allowance and weaning method affect the use of a computer controlled milk feeder and the development of cross-sucking in dairy calves

The effect of milk allowance and type of weaning on behaviour in dairy calves was investigated. A total of 72 calves divided into 6 blocks of 12 calves were used. The calves in each block were divided into two groups and housed in a separate section containing two straw-bedded pens, each with a computer controlled milk feeder. Within block, calves were assigned to either a low milk allowance (4.8 l/day for heavy breeds and 3.6 l/day for Jersey) or a high milk allowance (9.2 l/day for heavy breeds and 7.2 l/day for Jersey), while concentrate was feed ad libitum. One group in each block was assigned to gradual weaning from 6 to 8 weeks of age, while the other was assigned to abrupt weaning at 8 weeks of age. Recordings of cross-sucking were done on days before, during and after weaning, and use of milk and concentrate feeder was recorded throughout the experiment. Abruptly weaned calves performed more cross-sucking than gradually weaned calves immediately after weaning (P < 0.01), while this difference was not found 4 days after weaning. Before weaning was initiated, calves on a low milk allowance had more unrewarded visits to the milk feeder than calves on a high milk allowance (P < 0.01). During the weaning period, calves on an unchanged milk allowance had a lower number of unrewarded visits (P < 0.05) to the milk feeder than gradually weaned calves. However, the first 5 days after weaning, they had longer duration (P < 0.05) and a higher number of unrewarded visits (P < 0.01) than gradually weaned calves. These results indicate that gradual weaning of calves reduces cross-sucking and unrewarded occupancy of the milk feeder compared to abrupt weaning. Furthermore, a high milk allowance reduces unrewarded occupancy during the milk feeding period.