Cognitive development is a term more commonly heard in university psychology classes than agriculture research. But how a dairy calf’s brain develops has implications for housing systems.
Whether farmers decide to house calves individually, in pairs or in groups, each housing system has its advantages. In the first few weeks of a calf’s life, most health problems are linked to contagious diseases or nutrition, according to Canada’s Code of Practice for the Care and Handling of Dairy Cattle.
But individual housing can limit a calf’s social interaction and exercise.
“As soon as you put them in pairs, it makes an incredibly more complicated environment for the animal. And it turns out that has a bunch of positive effects for the development of that calf, including providing a social model for learning how to eat,” says Dr. Dan Weary, professor at the University of British Columbia’s Dairy Education and Research Centre at Agassiz.
Weary, his colleagues and students have looked at how a calf’s problem-solving abilities are affected by her social environment. Calves housed in pairs catch on to eating solid foods more quickly than calves raised solo.
Catching on to solids earlier eases weaning stress and bumps the calf’s performance after weaning. Paired calves also bawl less than single calves because the pairs don’t depend on milk as much.
Rearing calves in pairs has other benefits, too. “The calves that are reared in social environments are much better able to (cope) with any other changes in their environment,” Weary says.
Once calves were put into a new group pen, heifers that were previously paired figured out the automatic feeders in about nine hours. Calves reared in individual pens needed nearly two days to figure out the same task, reducing their weight gains.
When introduced to new pen mates, previously solo calves also stood idle more, kicked more, defecated more and interacted less with other calves, compared to animals that had been paired.
Researchers also looked at how calves kept with cows fared. “There’s an expectation there that the mother might be especially important as a model for teaching calves what to eat, when to eat,” says Weary.
Calves raised with their mothers prior to weaning ate more solids, and caught on to solids earlier, than paired or solo calves. “It shows how well calves can do in terms of making that transition to solids,” says Weary.
Weary says the research leads to questions around how the industry can design practical housing systems that benefit calves.
How to do it
Switching to a paired system is as simple as removing the panel between two individual pens. But first dairy farmers may have to adjust their feeding systems.
Researchers at the Centre have been looking at milk feeding volumes for over a decade. Calves benefit from being fed eight to 10 litres a day, as opposed to four litres per day, says Weary. More milk also reduces competition for milk in paired housing systems. And feeding them milk through a nipple instead of a bucket cuts cross-sucking.
“I have more confidence in this recommendation than anything else. I’ve never met someone who’s been unhappy with doing that. You just get this lovely growth response and general thriftiness response from the calves,” Weary says.
“People don’t go back after trying that.”
Calves fed more milk at a young age do better than conventionally fed calves throughout their lives, as long as they’re weaned properly, Weary says. They also produce more milk.
Once calves are drinking more milk in a natural way, it’s very easy to try small groupings, Weary says. Calves can be paired when they’re two or three days old. Weary suggests trying it with just a few calves at first to get a handle on it.
“You can introduce one pair at a time, and also then you can slowly ramp up the skills of the calf manager as well, for dealing with this more complex way of taking care of their calves.”
— Lisa Guenther is a field editor for Grainews at Livelong, Sask. Follow her @LtoG on Twitter.