Do modern dairy barns make cows lame?

New research is showing that aspects of the cow’s environment, such as wet concrete floors, increase the risk of lameness. Freestall design can also affect lameness; for example, by increasing the time cows spend ‘perching’ half-way in the stall.

Sound complicated? The science in cow comfort is, in fact, relatively simple – identify behaviors that put a cow at risk for lameness and come up with ways to design and manage the barn to reduce these behaviors. To help design barns that reduce the risk of lameness, researchers at the University of British Columbia’s Animal Welfare Program have focused on two main areas of cow comfort:

1. the design of resting areas that promote lying time and reduce the time cows spend standing outside of the stall (i.e. on wet concrete)

2. identifying surfaces that are comfortable for cows to stand and walk on

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Increasing the comfort of the stall
Stall size and configuration can affect standing and lying times. Cows lie down longer in wider and longer stalls. Any additional hardware, such as a lunge barrier, neckrail and brisket board, acts as obstacles limiting the available space for the cow and restricting her movement when she lies down and stands up. Narrow and short stalls result in more time spent with only the front two hooves in the stall, a behavior known to increase the risk of lameness.

The freestall lying surface is one of the most important features of the resting area and is often the aspect that is easiest to modify. Soft, well-bedded surfaces such as deep-bedded sand stalls promote lying. Dry deep-bedded stalls can increase lying times by several hours a day and reduce the risk of hock lesions that are another cause of lameness.

Although deep-bedded stalls provide many benefits for cows, they require maintenance. Bedding levels decline in the days after filling, and cement curbs, brisket boards, and stall partitions become greater obstacles for the cow. Cows lie down one to two hours less every day if bedding has not been added over a week. Cows also prefer to lie on a dry surface and will lie down as much as five hours a day longer when bedding is dry and clean compared to wet and dirty.

Another important aspect of facility management is stocking density (i.e. the number of cows per lying stall). Even modest levels of overstocking reduce lying times, and overstocking pens by 50 percent reduces lying time by close to two hours per day. The reduction in lying time is matched by an increase in time spent standing outside of the stall, again increasing the risk of lameness.

Improving her standing surface
Even with well-designed and managed freestalls, cows spend about half of their time outside of the stall. Providing a soft, dry surface for cows to stand on is important in any barn and is a key factor in reducing the risk of cows becoming lame. Indeed, access to a better standing surface can even help lame cows recover. For example, one recent study showed that in as little as two weeks on pasture lame cows walk more smoothly. This improvement in gait is not because of increased lying times – cows on pasture usually spent less time lying down. Rather, pasture helps lame cows recover because it provides a comfortable (i.e. dry and soft) place to stand.

A goal for the future is to develop indoor standing surfaces that provide similar benefits as pasture. Research to date shows that good rubber flooring can provide some benefits. For example, cows will typically choose to walk upon a soft, rubber floor and avoid concrete. Cows also slip less frequently and walk more smoothly on well-designed rubber surfaces compared to concrete flooring, a difference that is especially clear for lame cows. That said, research on flooring is still in its infancy, and it seems that none of the current options is ideal.

In most barns, the freestall is the driest and softest place for cows to stand, but stalls are typically configured to make standing in the stall difficult or impossible for many cows. The one stall feature that most restricts cows from standing fully inside the stall is the neckrail. If we could fit each cow to her own stall, we might be able to configure the stall so that she could stand comfortably but also indexed inside the stall such that her urine and feces would fall in the alley. In practice, this indexing is ideal but rarely achieved. Rather, in an attempt to keep the stall clean, the neckrail is positioned such that many cows are unable to stand in the stall and instead spend time perching or standing outside of the stall, increasing the risk of hoof problems and lameness.

Take-home messages
Designing barns with stalls that are comfortable for lying down helps prevent lameness; keeping stalls well-bedded and well-maintained is especially important. Comfortable standing surfaces are another key factor. Well-managed pasture may be the ideal, but soft, dry indoor surfaces are a major improvement over the wet concrete flooring found on many farms. Cows can also use the freestall as a refuge from poor standing surfaces elsewhere in the barn, but only if the stalls are designed to allow standing. Positioning the neckrail so that cows can stand fully in the stall is one way to improve the cow’s standing area, but this requires extra management to keep the stall surface clean. PD

Katy Proudfoot
Ph.D. Candidate
University of British Columbia
kproudy@gmail.com