Dairy farmers are always looking for ways to be more efficient and productive on their farms, while also creating the best welfare environment for their animals. For organic producers, the practice of raising calves on cows is gaining more traction for all these reasons.
One research group is studying this concept with hopes of understanding the practice and its long-term influence on the calves.
“We’re going to follow these calves through their first lactation to look at growth and behavior as they come into the milking parlor, and we’re going to be doing some economics,” Brad Heins said. “This is one of the first projects documenting calf-raising in organic systems, especially with calves on cows. No doubt feeding calves, whichever way, is work and takes labor. So, does it pay off this way?”
Heins is an associate professor at the University of Minnesota-West Central Research and Outreach Center in Morris. During an Aug. 5 field day, Heins and his graduate students shared their research studies of raising calves on cows in the crossbred organic dairy system.
The purpose of the study, which began spring 2020 with 16 calves, is to evaluate four ways of raising calves. To date, Heins has raised about 40 calves on cows, comparing their growth and development to calves raised in individual hutches, in pairs and groups of six; a late group of three calves and cows remain for the summer.
It is anticipated the study will continue another two years until the research center can evaluate about 100 calves raised by cows.
“We have a seasonal herd where we calve in the spring and fall,” Heins said. “It takes time to get enough animals for us to effectively compare all housing systems, and also look at health and behavior.”
A calf is born in a compost barn and allowed to bond with the cow for three days before the pair is included with the remainder of the calves-on-cows herd. In the spring time, they come out on pasture for the season.
Each calf receives a CowManager tag to monitor activity level, and they wear pedometers to track movement and behavior as it may relate to growth.
“These are moms and calves,” Heins said. “At this time, we are not doing nurse cows.”
Heins noted that while most calves and cows remain united for the duration of nursing, if the group is large enough, older calves have been found to figure out which cow has more milk and steal from that mother.
“We’ve seen it where the cow is raising her own calf on one teat, and on the other side of her is a calf stealing the milk,” Heins said. “One of our goals is to figure out production level and how it responds when the calf is weaned. That’s hard to document, though, because we don’t have cameras out here to know where the milk is going.”
Cows are milked twice a day in the research center’s milking parlor. As cows enter the facility, calves are sorted out.
The researchers have found that the cows nursing calves have significant milk production for the first three to four weeks of their lactation.
“Some cows are still milking 30 pounds of milk per day at that time,” Heins said. “The cows later in lactation maybe have 4 to 5 pounds per day while nursing a calf. Then once weaned, some go back up to 40 to 50 pounds of milk per day in a week’s time. That’s how we know that calf is drinking as much as they can get.”
The study is weaning calves at 9 to 10 weeks of age.
“There’s debate whether that’s long enough or not,” Heins said. “Those calves are nice and big. Their gain is pretty good.”
Of the three remaining calves on cows for this calving season, the average weight at the time of the field day was 300 pounds. To date, the study has reported an average daily gain of 3 pounds of growth per day at the time of weaning; the other calves in the study are gaining about 2 pounds per day.
“What are the problems with them growing so fast?” Heins said. “That is something we’re monitoring and will find out.”
For the weaning process, calves are immediately taken off the cows in groups of six; for logistical reasons this was the best option. The animals are receiving cortisone before and after for researchers to monitor if there is any acute stress with weaning.
Calves go into a separate area where they can be fed grain and water, and monitored for five days before joining the weaned herd.
“We’re watching the behavior dynamics to see what happens when we merge all the calves together, regardless of how they were raised,” Heins said.
In Heins’ observations, the cows experience more stress in the weaning process than the calves.
“Those cows are the first to the milking parlor for a week. They’re sprinting, looking for their calves much like beef cows,” he said. “The calves bellow a bit, but they’re with other animals. It is quite dynamic and quite different than what everyone is used to.”
The study’s 16 pilot calves are bred and will calve next spring to further the research.
In 2022, Heins and his colleagues are planning to implement an on-farm component to the study which will provide further insight to this type of housing practice.