Lameness remains one of the top health issues dairy farms battle, and it is also a serious animal welfare concern. While it is easy to call cows that struggle to get to the parlor “lame,” in reality, those are only the severe cases. Any cow that has difficulty putting weight on a limb is dealing with lameness, reminded Nigel Cook on an episode of the American Association of Bovine Practitioners “Have You Herd?” podcast.
He cited that globally, approximately one-fifth of cows walk with a noticeable limp. “I still think that’s intolerable,” said the professor at the University of Wisconsin-Madison.
An integral part of controlling lameness is optimizing lying time, therefore limiting the time a cow is standing on her feet. Cook said we must not only think about the hours in a day a cow can lie down but also make sure she can lie down when she wants to do so.
What determines lying time?
Cook identified four factors that impact how free a cow is to choose to lie down: stall surface, opportunity to rest, overstocking, and heat stress.
Stall surface will either encourage a cow to lie down or lead her to keep standing longer. What we want to provide is a soft cushion for cows to rest and easily be able to get up and down. This is especially important for cows that have some degree of lameness because the pain makes that movement harder. This means they get “stuck” lying down or standing up when they may want to do the opposite. “It’s that transition from lying to standing and standing to lying that they really struggle with, and that’s where the surface of the stall has a role to play,” Cook said.
He noted that farms have achieved a 40% reduction in lameness when they move to deep-bedded sand, which provides unbeatable cushion and traction, especially when cows are compromised. But that is not the only option in bedding. When sufficiently dried, deep-bedded recycled manure solids can also provide sufficient cushion. Even mattresses, when managed well, can work. Cook advised making mattresses softer by adding foam under the cover or a bedding retainer to allow for deeper bedding.
The structure of the stall also matters. It is a balance of providing sufficient room for the cow to lunge and also enough guidance to index animals and keep stalls clean, Cook described.
Even if stalls are designed so that cows want to lay in them, they must have time to do so. Cook advised having cows out of the pen for no more than 3.5 hours a day so they can meet their desired time budget of eating, resting, and socializing. This opportunity to rest can be compromised by poor parlor efficiency or long periods of herd checks.
When cows are excessively standing on concrete during these times, the hoof will flatten and erode, causing more problems like sole ulcers, thin soles, white line disease, or digital dermatitis that can all lead to lameness. While adding rubber in strategic locations can be helpful, it should be secondary to fixing the lying surface. “The best flooring surface is one a cow doesn’t stand on for half the day,” Cook said.
Standing time also climbs when pens are overstocked and cows can’t access stalls. “You are compromising lying time, and that will come back to bite you,” Cook continued. While adding more animals will provide a temporary boost in total milk production, cows will suffer and make less milk individually with less time to ruminate.
Heat stress is the final factor that determines lying time. Hot cows will stand more and bunch more, which puts more pressure on the feet.
Prioritizing rest requires a mindset shift, and Cook recognized that it is not often the first consideration when designing a barn or choosing stall materials. He encouraged farmers to focus on the cow first when making these decisions and sort out manure handling and facility considerations after that.
