One is the loneliest number

There’s evidence that pair or group feeding for calves is better, but will farmers buy into it?

Dr. Marina von Keyserlingk, professor and dairy welfare researcher at the University of British Columbia, has conducted extensive research on pair and group feeding of dairy calves.

“There are lot of things we know work well, but I appreciate that every dairy farm is different from every other dairy farm,” von Keyserlingk said. “Historically, scientists and experts have taken the attitude ‘Let’s tell people what they have to do and make a wild assumption that everything will work well.’”

Although von Keyserlingk is an animal welfare specialist and researcher, she understands the farmer’s perspective and realizes it’s difficult and expensive for farms to make major changes to housing systems.

Von Keyserlingk said that when she started research on pair feeding in 2002, most farmers in North America limit-fed calves. Calves were single housed and fed an average of four quarts in two feedings/day. Calves were fed milk in buckets, which they sucked down in 45 seconds.

“Then they suck on whatever else is out there – chains, buckets and other calves,” von Keyserlingk said. “Calves weren’t fed forage because they would get hay bellies. Our solution was to individually house them. My job is to think about ‘What are calves highly motivated to do, and how do we adapt the environment and management system to allow calves to engage in natural behaviors?’”

When calves are free to express natural behaviors, they mimic many of the feeding behaviors seen when they are with the dam. In nature, a cow nurses her calf about five to 10 times a day, each nursing bout lasting about five to 10 minutes. Calves in nature also drink far more than four quarts of milk/day.

“When calves have free access to milk, they spend, on average, about 45 minutes a day drinking,” von Keyserlingk said. “They drink more than 10 quarts a day, they have as many milk meals as if they were on the cow, and they divide it over six to 10 milk meals.”

One of the challenges when calves are fed a lot of milk is little interest in starter feed. Von Keyserlingk said farmers have come from the tradition “We need to get them on starter, so let’s not give them milk and hope they will eat starter.”

“Historically, we didn’t feed a lot of milk because we wanted them to eat starter,” von Keyserlingk said. “But even calves that were not fed a lot of milk hardly ate any starter before four weeks of age. Baby calves are monogastrics when they’re born – they have to become functional ruminants. Their rumen is not set up to eat starter before three to four weeks of age. Forage isn’t something they’re eating for nutrition, but they are becoming ruminants and need fiber from forage. A little bit goes a long way in rumen development.”

Von Keyserlingk is convinced that many milk-fed dairy calves without forage in the diet are suffering from rumen acidosis. She noted that calves that had forage from day one had more developed, heavy rumens and were better prepared for weaning and solid food.

When farmers change something, they need information about it. This results in caring about and trying the new system.

“It’s a series of trial and error we called the ‘reinvention stage,’” von Keyserlingk said, adding that this stage can last for weeks to months and even years. “We found that after implementing social housing, participants faced and continue to face challenges.”

For pair or social housing, the maximum group size should be eight animals to more easily manage a disease outbreak. If possible, it’s best to fill a pen and take the group through to weaning, then empty the pen and clean it.

One farmer who decided to stay with social housing said, “It’s so much better for calves – they are easier to feed, happier and they have more room to run, and learning how to interact in a group.” For him, the benefits outweighed the negative of dealing with cross-sucking. Another farmer found that while pair housing was more difficult to manage, heifers were far easier to train to his robotic milking system.

Von Keyserlingk knows cross-sucking is a huge challenge for farmers. “Cross-sucking research is hard, especially on-farm research, because it doesn’t happen all the time,” she said. “In all studies where treatment included a cow and calf contact, there was almost never any sign of cross-sucking compared to teat-fed or bucket-fed calves.”

Studies showed there is far less cross-sucking when calves are fed with a teat. For dairies that bucket feed calves, the first challenge is to encourage calf feeding staff to feed with nipples because social housing will require nipple feeding.

“Some people want to get milk feeding done faster so they make the hole in the teat larger and calves slug down the milk,” von Keyserlingk said. “Calves are highly motivated to suck, and we want saliva. The harder they have to suck a nipple, the more they get the sucking out of their system and it seems to prevent cross-sucking.”

The solution is smaller holes in nipples and switching out nipples as soon as the holes become larger.

Von Keyserlingk advised farmers interested in pair or group housing to feed more milk and avoid making sudden changes.

“We are already messing with nature,” von Keyserlingk said. “In nature, calves would have access to milk for six to eight months and we are weaning them at eight to 12 weeks. The reason we try to wean then is they are far more vulnerable to disease during the milk feeding period and we can decrease mortality by getting them off milk.”

Calves will eventually become ruminants, and forage plays an important role in facilitating that transition when they are provided higher volumes of milk. When calves are restricted to four quarts/day and there’s forage in front of them, they eat it because they’re hungry. They eat too much forage and get hay bellies.

“Changing management practices on farms is hard and not instantaneous,” von Keyserlingk said. “Farmers need continuous support from veterinarians and other key stakeholders that help in managing the farm. To have that access will be key.”

by Sally Colby