Lameness and lying time are linked
If your stalls keep cows from 12 hours of daily rest, lameness rates are likely to rise.
by Tars Cheema
Following a long career in dairy genetics, the author now writes and consults in the dairy industry. He is based in British Columbia, Canada. Major funding to support the extension work of the BC Dairy Hoof Health Group comes from Investment Agriculture Foundation, Westgen Endowment Fund and DIREC (BC Milk Producers).
add another 2 feet for lunge space.
When I grew up dairying in the 70s, a simple shot of penicillin would take care of the odd case of foot rot that might crop up after the cows had been pasturing on soggy ground, and digital dermatitis wasn't even on our radar. Hoof trimmers were occasional visitors who didn't carry blocks. Freestalls were mostly homemade, and we complained about the work of leveling/filling the deep dished-out stall beds. But we had plenty of old cows.
The advances in dairying over 30 years have been staggering and, yet, cow comfort, mobility and longevity have all faltered.
With the realization that feet and leg issues are widespread, extremely costly and very complex, momentum has been growing in recent years to coordinate an industry-wide approach to accurately measure the levels, determine the causes and devise solutions for our lameness woes. The British Columbia Dairy Hoof Health Group in Canada is one such industry body that has focused special attention on addressing lameness and cow comfort by spearheading extension efforts and data collection. Recently, a Dairy Facility Design Conference was organized by the group in Abbotsford, British Columbia. This article captures many of the take-home messages as they pertained to cow comfort and lameness.
Cow comfort must come first
It starts with one simple rule: anything that interferes with cows getting or exceeding 12 hours of lying time per day is likely to result in higher rates of lameness. In most cases, the drive to maximize barn efficiency from both cost and labor perspectives has led to smaller stalls with aggressive "cow locators" (brisket board, neck rail) and beds that require minimal bedding and upkeep. If you give cows a choice between different stalls, they will soon tell you which are the most comfortable.
Stalls must be long enough and wide enough while providing deep, dry bedding, and neck rails/brisket boards that allow plenty of room to lunge and stand without impediment or discomfort. The breed and size of cow will factor into the stall design and dimensions.
Harold House, an ag engineer with Ontario's Ministry of Agriculture, presented extensive diagrammatic detail of stall design essentials. Your average Holstein cow needs a 50-inch-wide stall. Dry cows need more space, and slightly less is required for 2 year olds. It is important to include lunge space when considering stall length for cow comfort. When facing a wall, 8 feet of laying space plus 2 feet of lunge space is required. If the stall is open to another stall or an alley, 1 foot of lunge space is necessary.
Similarly important is the placement of the brisket locator and neck rail. Far too often both are aggressively positioned to force cows to lie far back in the stall. This forces them to step back immediately when they rise in order to reduce stall cleaning, putting labor convenience ahead of cow comfort.
The brisket locator must be no higher than 4 inches to permit unobstructed lunging. The neck rail position can be extremely discouraging to cows that want to lie down, often confirmed by the number of cows seen "perching," or standing with their front feet on the back end of the stall.
Neck rails can also be located too low when rigidly attached to the top of stall dividers which are not high enough from the bed surface. More than one expert recommended that neck rails be moved well forward, higher or removed completely to facilitate maximum comfort and freedom from obstruction and injury. Some additional labor to clean the stalls was seen as a minor investment in favor of greater returns from healthier cows.
Bedding and stalls linked to lameness
Dan Weary, University of British Columbia, indicated that deep-bedded stalls were associated with a dramatic lameness reduction; 50 percent fewer lame cows. Similarly, when herds had access to pasture for some duration of their dry period, there were 50 percent fewer lame cows. Sand or deep dry bedding materials were far superior to rubber, mattresses or concrete stall surfaces.
The incidence of hock lesions was greatest on mats and least on deep sand. The positive attributes of sand bedding, deep sawdust or deep compost bedding were also confirmed by House, who stressed the benefits of materials that provide cushioning, traction, absorbency and low abrasion.
John Dick, a dairy veterinarian, outlined that cow comfort assessment should start by looking at the cows. Lameness is a big indicator of how comfortable your cows are. It is a reliable, repeatable measure of your herd's comfort status and can assess the benefit of changes you make over time, especially if you use an objective scoring system accurately. He pointed the finger at both laminitis (sole hemorrhages and ulcers) and digital dermatitis as major contributors to lameness rates.
Besides nutrition, barn design and stall comfort can affect laminitis if cows are standing more and putting greater strain on the lamina tissues in the hoof. Regarding stalls, Dick emphasized that more effort must be made to raise lying time for cows by addressing the primary deterrents which, in his view, are lack of bedding and incorrect neck rail placement.
Packs win comfort contest
While freestall barns are certainly the overwhelming housing environment in developed dairy countries, it is worth noting that deep-bedded pack barns do have their advantages. Although more area and bedding per cow is required, the packs do win the cow comfort race. Some herds utilize tractor-driven surface grooming implements to keep the bedding refreshed or simply add fresh bedding frequently to maintain cleanliness. More herds are making use of the continuous supply of "compost" from their manure solids separators in both stall or pack situations.
House recommends that compost be mostly dry before use and care be taken to deal with it quickly as it becomes wet or soiled. This applies to other bedding types, too. Compost should not be permitted to reheat in any bedding application. Pack pens are much more common housing styles for dry, close-up or hospital cows. While no producer wants the work that comes with a large number of cows in a hospital pack pen, getting lame cows out of the freestall barn and onto a pack, or even in a paddock, for several weeks can allow a great deal of recovery to occur.
Lameness can be the result of many intersecting variables, well beyond the issues of stall design, bedding and surface type. There is ample data to show that lameness rates vary widely between herds and regions - providing clear evidence that lameness can certainly be reduced. Prevention, though, is by far the most successful and preferred method. Start with assessing your current herd level, analyze your facility, and make changes to improve cow comfort and boost lying time.