Toronto: Cows learn better when housed together, which may help them adjust faster to complex new feeding and milking technologies on the modern farm, a new study has found. University of British Columbia researchers found dairy calves become better at learning when a "buddy system" is in place.
The study also provides the first evidence that the standard practice of individually housing calves is associated with certain learning difficulties. "Pairing calves seems to change the way these animals are able to process information," said Dan Weary, corresponding author and a professor in UBC's Animal Welfare Programme. "We recommend that farmers use some form of social housing for their calves during the milk feeding period," Weary said.
As farms become increasingly complex, with cattle interacting with robotic milkers, automated feeding systems and other technologies, slow adaptation can be frustrating for cows and farmers alike, researchers said. "Trouble adjusting to changes in routine and environment can cause problems for farmers and animals," Weary said, adding that the switch from an individual pen to a paired one is often as simple as removing a partition. Farmers often keep calves in individual pens, believing this helps to reduce the spread of disease. But Weary said that the concern is unwarranted if cows are housed in small groups.
The study, conducted at UBC's Dairy Education and Research Centre in Agassiz, involved two cognitive tests for two groups of Holstein calves housed in individual pens or in pairs. In the first test, researchers introduced a novel object (a red plastic bin) into the calf's pen. When first exposed to the novel object all calves showed interest, as expected. But after multiple encounters with the bin, the individually housed calves continued to respond as if this was their first exposure, while the paired calves began to habituate and ignored the bin. "The test suggests that individual rearing can make calves more sensitive to novelty, and thus less able to habituate to changes in their environment," said Weary.
In the second test, the calves were taught to complete a simple task, approaching a black bottle full of milk and avoiding an empty white bottle. After the calves learned to preferentially visit the black bottle, the researchers switched the rules to determine how well the calves were able to adjust to a change in rules. "At first, both the individually housed and pair-housed calves initially struggled with the task, but after a few training sessions the pair-housed calves began approaching the correct bottle while the individually housed calves persisted with the old strategy, visiting the incorrect bottle more often," said Rebecca Meagher, co-author, and a postdoctoral research fellow in UBC's Animal Welfare Programme. The study was published in the journal PLOS ONE.
