By Cate Willis

A University of Guelph study has found that reducing cow milking frequency can help treat ketosis, a common metabolic disorder that occurs within two weeks of delivering a calf. 

Dr. Todd Duffield [1], a professor in the Department of Population Medicine [2] at the Ontario Veterinary College (OVC) [3], led the study along with other researchers from OVC and the Ontario Agricultural College (OAC) [4]. The team aimed to help dairy producers and veterinarians improve ketosis treatment on farms. 

Post-calving, dairy cows can experience a negative energy balance when their feed intake is too low to meet the energy requirements for body maintenance and milk production, says Duffield. Typically, producers treat ketosis by administering propylene glycol, but it isn’t always effective.  

“Up until this work, no one had looked at temporarily reducing milking frequency as an additional treatment to help cows get through ketosis and recover,” he says. “Our study did that and it worked.” 

The study was conducted at the Ontario Dairy Research Centre, which is owned by the Agricultural Research Institute of Ontario and managed by the University of Guelph through the Ontario Agri-Food Innovation Alliance. 

Cows with ketosis were randomly assigned to milking twice a day or reduced to milking once a day for two weeks. The cows that were milked once a day returned to milking twice a day after two weeks.

Both groups also received propylene glycol for five days to help treat ketosis. 

The team found that when ketotic cows were milked once a day, their condition quickly improved.  

“The speed at which there was a metabolic impact was surprising,” Duffield says. “There is clearly potential for modifying milk production to treat ketosis. 

“The only issue was that temporarily reducing milking frequency had a negative impact on milk production.” 

He hopes a subsequent study will determine whether a shorter-duration treatment will manage ketosis. 

“We did 14 days and at the outset of the project,” Duffield says. “We weren’t sure what impact this would have on the cows, but the effect was pretty quick and dramatic, so maybe a future project could have a shorter duration. 

“The five days makes sense because that’s how long we would typically treat cows with propylene glycol. We tend to treat them for three to five days.”  

Other members of the team were master’s student Maggie Williamson, post-doctoral researcher Dr. Rita Couto Serrenho, Dr. Stephen LeBlanc from OVC’s Department Population Medicine, and Dr. Brian McBride and Dr. Trevor DeVries, both professors in OAC’s Department of Animal Biosciences. 

This research was funded by the Ontario Agri-Food Innovation Alliance [5], a collaboration between the Ontario Ministry of Agriculture, Food and Rural Affairs [6] and the University of Guelph.