Lameness in the US Cattle Industry
Lameness is a significant welfare and economic concern for the US cattle industry. Estimates across published studies indicate that as little as 1.1% to as high as 54.8% of US cattle are clinically lame. Cattle auction market audits find that nearly 30% of mature animals display some amount of lameness. Dairy animals are more highly represented in the population of lame cattle, but lameness is a significant issue in beef cattle as well. In a 2013 study auditing slaughter plants nationwide, 16.2% of beef cows and 31.3% of beef bulls were lame. That compares to 48.6% of dairy cows in the same study population. A dataset published out of Arkansas found that head cows showing visible lameness were discounted an average of $6.97/cwt at auction market. A similar study published in 2011 out of the Western States found that discounts per hundredweight increased significantly as clinical lameness score increased. Discounts ranged from $1.32 for mild lameness to $14.88 for severe lameness in beef-type cows, and $1.76 to $12.62 for dairy cattle. Productivity of lame animals is thought to be less, but published data is harder to come by given the variety of experimental designs and clinical definitions of lameness. Lame dairy cow lactation performance is significantly decreased in some studies, but others (usually involving a treatment) find no difference in milk yield between healthy and lame cows following treatment. Data in the beef sector is sparse and mainly relevant to feedlot cattle. Lame steers tend to underperform compared to healthier cohorts in that they have increased costs, decreased feed efficiency, lower carcass weights, and decreased carcass quality.
It is important to point out that lameness is not a specific disease, and certainly not an entity that can be treated directly in every case. Lameness is a clinical symptom of a wide variety of diseases. The more common issues I see can be broken down into two categories: infectious and non-infectious. Infectious cases of lameness generally are related to footrot or digital dermatitis (hairy heel warts). Both diseases are typically known by producers and over-the-counter antibiotics are generally effective against early, uncomplicated cases. When I get involved, primary treatment has either been ineffective, or the disease has progressed to something more serious such as deeper infections of the structures of the foot or chronic lesions that require more aggressive therapy. Some resources cite footrot as the most common cause for lameness in beef cattle, while others cite structural problems with the foot/claws. A published dataset out of Alabama’s vet hospital reports that 84% of beef cattle lameness cases were diagnosed to problems with the foot, with specific causes related to one or multiple of the following: screw claw, vertical cracks in hoof wall, interdigital fibromas (corns), or sole disease. All of these conditions would fall into the non-infectious category, and would not be treated effectively by antibiotics (prescription or over-the-counter). It is likely that this dataset is not reflective of the general population of lame beef cattle in that many infectious causes were treated on farm and did not present to the hospital. Treatment of non-infectious cases would require therapeutic hoof trimming. Causes for these diseases are multi-factorial, but the most likely culprits would be nutritional issues that lead to laminitis, conformational issues that cause uneven wear patterns on the claw horn, and unfavorable environmental conditions that weaken the claw horn.
The best plan for dealing with lameness at the farm level is to work with your herd veterinarian to:
- Develop a lameness identification protocol. Your veterinarian is an invaluable asset in the management of lame cattle on the farm. They can generate a reference guide to help you more quickly identify lame cows and get them appropriate treatment with the knowledge and expertise they possess. A scoring system published by Sprecher et al in 1997 has become the research standard for assessing degree of lameness, particularly in US dairy cattle. This assessment system, when applied regularly to animals by a trained observer, can identify lame animals much sooner than most routine animal observation studies reported. The 1 to 5 scale allows a producer to monitor animals as they progress through a production year and when 2 or more regularly spaced assessments show the animal as lame, further examination and appropriate treatment should be applied. This system (and others like it, such as Zinpro StepUP Beef Cattle lameness evaluation scale) are effective screening tools for determining herd-level lameness incidence as well as individual animal disease progression. The important part to remember is that these tools must be applied regularly and consistently. Otherwise, they do little good. Published research in dairy cattle indicates that lameness prevalence is likely three times higher than farmer-reported estimates through use of identification systems such as these.
- Define appropriate treatments AND treatment timeframes for lame cattle. Once cattle are identified as lame, your veterinarian will recommend examination to diagnose the cause of the lameness. From there, treatment specific for the disease identified will be recommended and/or administered. Standard treatment protocols and decision algorithms can be developed specific for your farm based on the relationship you and your herd veterinarian have. An important component of any protocol is critical control points that involve when it is appropriate to manage on farm without vet supervision vs. when it is time to call the vet. As is most often the case in my clinical practice, lameness issues have become chronic by the time of evaluation, which necessitates repeated treatments for the cases that can even be treated at all. These cases are particularly frustrating because we often feel that a different outcome would have been likely had we seen the case sooner. For single treatments to be effective they must be applied early in disease process. A UK study looked at treating cows within 2 days of receiving a score of 2 on the previously described scale. 67 cows were treated on research protocol, while 101 control cows were identified but left for treatment according to normal farm protocols. Farmers were not informed of locomotion scores. In the control cow population, treatment on average lagged by 15 days from original lameness diagnosis, but only 22% of control animals were ever identified and treated for lameness by farm staff. At 4 weeks into the study, incidence of lameness in treatment group was significantly lower than in control group. It was noted that 30% of control cows returned to soundness (self-healed) without treatment for at least 4 weeks, indicating that there are some issues with the scoring system (picks up relatively high rate of false positives). The most common lesion in treatment cows was sole bruising, while the most common disease in treated control cows were sole ulcers and white line disease. This indicates that control cows were later in the same disease process that affected the treatment group. It could be argued that animal welfare was significantly improved via early treatment as the disease did not have time to progress to more serious conditions. Additionally, treatment group cows rarely received follow-up treatment and tended to have higher milk yields than control cows.
- Implement prevention strategies as necessary. While effective identification and treatment of lame cows is important to animal welfare and economic success of the farm, every lame cow represents a significant liability to the farm. Even those that are promptly found and effectively treated will not be as productive as an animal that never got lame in the first place. Therefore, prevention strategies are far more valuable than steps 1 or 2 in this article, in my opinion. While the goal of preventing of every single case is admirable, it is likely unachievable. That being said, dropping herd-level lameness issues should be achievable for every farm. Acceptance of a certain level of lameness is not something our industry should tolerate. Lameness prevention strategies are like the disease – multi-factorial. Your herd veterinarian is again your best source of information and technical skill for achieving lameness reduction goals. The high points for a prevention strategy should focus on providing adequate nutrition, selecting appropriate genetics, and ensuring adequate environmental conditions to decrease susceptibility to most common lameness diseases on your farm. From a nutritional standpoint, providing cattle with a well-balanced, consistent, and appropriate diet is paramount. Fluctuations in fermentable carbohydrate levels are inevitable, but helping to smooth those transitions out with grazing planning and/or ration balancing is practical for the conscious producer. High quality mineral provision is also very important for claw horn integrity and health. Genetic selection for animals with the right body type for your management system can greatly reduce incidence of lameness within a herd. For example, if free-stall dimensions on a dairy are designed for a 1300 pound Holstein cow, but the average cow on your dairy is 1700 pounds, we would expect there to be a higher prevalence of lameness on the dairy because they cannot physically squeeze into their resting place. Similarly, beef bulls that produce highly marketable weaned calves may not produce very good replacement heifers. These females won’t hold up well in a grazing system long-term because of their genetic programming to grow rapidly and put on high amounts of muscle and fat, which can lead to skeletal development issues and conformational problems later in life. Environmental management is the hardest part of the equation, as we can’t control weather patterns or basic cow behavior very well. Extended periods of wet or dry can predispose cattle to lameness issues. Intensive management systems also can predispose animals to issues, specifically if management leads to high stocking densities or keeping animals on concrete floors for extended lengths of times.
Lameness is a significant issue for most producers I work with, whether that be due to the affliction of one valuable animal or a high number of herd members being affected at one time. Treatment of lameness also represents one of the larger areas for improvement in the cattle industry on prudent use of antibiotics. Involving knowledgeable veterinarians in the development of lameness management and prevention protocols will pay in herd management and consumer confidence in our products. Vets can act as sources of knowledge, provide a third-party objective evaluation of farm practices, and act as direct service providers or as liaisons with other service providers to improve farm management. More importantly, in today’s consumer-driven market, vets can provide the resources to effectively improve animal welfare and ensure judicious use of antibiotic use on farms.