Hoof issues leading to lameness (failure to have a normal locomotion gait) is recognized as a problem in the dairy industry, prevalent in herds of all sizes and facility type.
Despite awareness of the problem, lameness severity and its rate of incidence continue to increase. Recently, a University of Minnesota study observed an average lameness rate of 24.6 percent among all U.S. herds. This statistic was 3.1 times higher than the commonly believed and estimated rate among herd managers.
History and recent changes
Reviewing my file on dairy lameness, which goes back over four decades, it is apparent that how we now view and approach lameness has changed. In the 70s, much of the information focused on foot rot and dietary mineral recommendation. In the 80s, the focus was on laminitis related to rumen acidosis and slug feeding grain. In the 90s, sub-acute rumen acidosis was emphasized as causing laminitis, chelated trace minerals were incorporated into diets and digital dermatitis (hairy heel warts) was recognized as an emerging problem.
The current decade has found us looking closely at facility design, cow comfort and dietary nutrient modeling as ways to reduce lameness. So far in 2009, we still have too many profit-robbing lame cows. In fact, there are so many lame cows that many owners and herdsmen no longer see enough non-lame cows to recognize what a normal locomotion gait looks like when estimating the percent of herd lameness. Many early lame cows that are “still getting around” are judged to be OK and therefore in the normal category.
What we have learned over the years is that lameness is more than an individual cow problem. It is a herd management issue that involves the areas of hoof and leg conformational genetics, facility design and flooring, nutrition’s influence on rumen pH, intervention with preventative foot trimming and hoof health maintenance with footbaths. Genetics and hoof and leg skeletal conformation is the foundation of the animal. This must be addressed through genetic mapping of the herd. Fortunately, this trait has become easier to assess with current, updated information.
Today’s cow housing
Cow housing and facility type have changed dramatically. Cows have moved from a pasture-based grazing stanchion barn for milking to a tiestall housing/milking barn with a dry lot for exercise. A majority of cows are now housed in freestall facilities and milking parlor. Bedding packs are being evaluated as an alternative for sheltering lactating cows. Cow comfort relating to stall design is currently being emphasized along with sand bedding to encourage more lying time and preventing associated leg trauma and soft tissue damage that can lead to lameness.
Detailed information on building design and recommended stall dimensions can be obtained from university ag extension services and from visiting successful dairies. I suggest doing both. Seeing working recommendations in real life that have a history of meeting the goal of maintaining hoof health is effective planning. The shift in facility type and increase in herd size has allowed for approaching lameness on a herd basis. It is now possible to set up foot baths and to have an area set aside specifically for hoof trimming.
Hoof wear and trimming
The recognition that routine scheduled hoof trimming by professionally trained hoof trimmers has in my opinion helped reduce lameness and maintain a reasonable cull rate.
Maintaining the correct hoof wall angle and toe length cannot be emphasized enough. Early detection of problems will prevent fewer cases of the chronic osteo-arthritic hoof lameness that is not treatable. Hoof wear is different today than what I initially encountered. Cow hooves on pasture or in a tiestall would typically be so hard and dried out that overgrowth was common. Trimming and hoof care was a task typically avoided due to the time it took and degree of labor output involved. But now the hooves tend to be overly hydrated from constant exposure to wet manure.
This hoof wall and sole condition often leads to abnormal wear patterns that need trimming and the hoof is more susceptible to exaggerated wear from new concrete surfaces or abrasive particles of sand. Nutrition Nutrition has always been part of lameness prevention. But how nutrition has been applied to the problem-solving has changed over the years. Lack of effective fiber and overfeeding grain has caused rumen acidosis, leading to laminitis and severe lameness. A better understanding of rumen microbial balance and the sensitivity to minor short-term low pH rumen events has evolved to feeding cows a diet which is carefully formulated.
Diets today are balanced for recognizing the importance of carbohydrate rate of digestion coupled with adequate degradable protein to maximize rumen bacterial growth while avoiding sub-acute rumen acidosis. Direct-fed microbials that consume lactic acid, addition of biotin, using chelated trace minerals and feeding a buffer are additives that aid in maintaining hoof health. Specific feeding recommendations need to be made for each dairy that will benefit hoof health at a justifiable cost level. The interaction of genetics, facility environment, hoof care management and nutrition are inseparable.
The importance of each area; housing, hoof attention, nutrition and genetics, will vary for each dairy and it is up to the dairy team to prioritize and focus on the areas that need the most attention for improving and maintaining hoof health. PD
Robert G. Ovrebo, DVM is on staff at the Form-A-Feed, Inc. and TechMix, Inc. companies located in Stewart, Minnesota. For more information, call 800-422-3649 or send an e-mail to firstname.lastname@example.org