by Deborah Jeanne Sergeant
Could improving the size and function of tie-stalls help your herd become happier and healthier? In a recent webinar hosted by Dairy Cattle Welfare Council, Elsa Vasseur explored the topic, sharing her organization’s research. She is an associate professor at McGill University in the Department of Animal Science and has been chair of the NSERC Industrial Research Chair Novalait-Dairy Farmers of Canada-Valacta on Sustainable Life of Dairy Cattle since 2016.
“Of course, when you think about welfare of dairy cows, I don’t know what you picture, but freedom of movement and animals going to pasture is probably at the top of the images that come to my mind,” Vasseur said.
She is not the only one. “It’s part of the quality of life expected by consumers, but restriction of movement is part of the reality for all domesticated animals,” she added.
Most cows spend much of their time in one of three scenarios: tie-stalls, free-stalls or deep-bedded pack. In tie-stalls, the animals rest in stalls, have access to food and water there and milking occurs at the stall. It’s the most restrictive management method. Free-stalls allow animals to leave at will to access food and water and milking occurs in a parlor or by a robotic milker separate from the stalls. This system is less restrictive. The deep-bedded pack management has no stalls. Cows access food and water at the edges of the pack and they are milked in a separate location. This is the least restrictive management method.
Vasseur presented the results of 10 years of cow comfort research focusing on stall management. The research was based upon 240 farms with an average of 40 cows per farm. The research included in-barn measurements, performance data and management questionnaires.
“We looked at lameness and lying time, measured things in the barns to look at the risk factors that relate to welfare,” Vasseur said. She said that in both free-stall and tie-stall systems, housing conditions affected the cows’ welfare.
The farm prevalence of hock lesions, knee lesions, neck lesions, dirty flank and dirty udder is higher for tie-stalls than free-stalls and bedded pack systems. Cows in free-stall systems experienced more incidences of dirty leg than either of the other systems.
Modifying tie-stalls proved to affect cow comfort. Tie-stalls moved forward by 35 additional centimeters decreased injuries by 42% and lameness by 24%. Resting time improved but cleanliness decreased by 20%. Increasing the chain length decreased injuries by 10%.
“One of the things with the tie-stall is you can measure the exact results of how the cow is housed,” Vasseur said. “If you move the tie rail where the chain is attached, we have a decrease of injury and lameness.”
The management does appear to affect production. The free-stall average cow experienced 7.4% fewer knee injuries, 11.7% less lameness, 26.9% less dirty flank and 9.9% more time in a stall with dry bedding.
“We knew that improving welfare could work to actually be translated into more performance, but there’s more work to be done,” Vasseur said.
She believes that increasing the movement opportunity in a tie-stall should be by improving the stall design to make movement easier. The study on these facets of cow care began with understanding how the animal was moving in the environment. “Can we improve the stall so the cow can move with ease?” Vasseur asked.
Cows with a longer chain move more, the researchers discovered. The presence of the wither outside the stall is higher for the cows with long chains than the current recommendation. “Longer chains than one meter seems to give cows a better chance of movement and it’s interesting to note that they use it,” Vasseur said.
She advised selecting cows that would benefit more from a longer chain and evaluating how they become accustomed to it. “The changes should be applied gradually,” she said. “Some cows will never use the extra lengths.”
Automation of video-based location tracking can help develop physical placement of the points within the stall environment. This research helped show that cows with “king-sized” beds exhibit better resting posture.
The cows entered the neighboring stall with their hind legs less often, preferred the second half of the stall for their hind legs and had their head more often in their stall and less often in the manger.
“No matter the width, the long-term prevalence of abnormal movements stayed very high,” Vasseur said.
The cows always maintained contact with the stall dividers or tie rail 43% of the time when lying in the double stalls versus 77% of the time with the current recommendation.
Researchers concluded that cows feel more comfortable with both larger tie-stalls and free-stalls; however, at the cost of construction, the current minimum width is much more economically feasible.
Vasseur’s team is also researching if housing modifications affect welfare status on milk composition using Fourier transform infrared (FTIR) spectroscopy.
“Milk cows tied with longer chains had lower levels of biomarkers associated with ruminal acidosis episodes,” Vasseur said. “FTIR spectra of milk could detect changes in milk composition attributed to positive and negative welfare status in cows.”
Those with a longer chain could have a more stable ruminal pH, which demonstrates better digestive health, likely because increase production of saliva containing the buffering agent sodium bicarbonate. Researchers also observed that these cows made more use of the manger and therefore had easier access to food and more time for rumination.
For cows in transition, it may be helpful to have them dry off in deep-bedded loose pens. “Transition is a nice start to get the cows out of the stall,” Vasseur said. “It makes it much easier in management to move them out of the tie-stall and in the deep-bedded pack.”
Cows in loose pens exhibited a greater variety of resting postures, more frequent posture changes and rested more than in tie-stalls. They showed no significant difference in the number of steps in the pen compared to the stalls; however, their condition overall improved.
“It’s not so much exercise but how the animal moves and what type of movement is offered to cows in different set-ups,” Vasseur said.
The cows offered access to pasture moved more indoors as well. Cows with more movement opportunities experienced better hoof health, human/animal relationships, thermal comfort and elimination and manure management.
“More work needs to be done to understand how we can add that new shift in management towards indoor exercise,” Vasseur said.