Impacts of Lameness – Part 2: Strategies for Identifying Lame Cows

Introduction

Lameness can have a detrimental effect on cow welfare, milk production, reproduction performance, and overall health of cows. It is essential for farmers to identify lame cows early and treat them as soon as possible. Early treatment of mild to moderate lameness can decrease the number of severely lame cows in the herd and decrease the costs associated with lameness. Dairy farm owners and herd managers often attribute the greatest expense of lameness to treatment costs, whereas the majority of costs stem from indirect costs and losses. Direct costs due to lameness include treatment, veterinarian/hoof trimmer fees, and producer labor. Indirect costs and losses include reduced milk production, increased risk of death and culling, increased incidence of other diseases, nonsalable milk, and reduced reproduction performance. The economic impact of lameness is significant and the second most important step for effective lameness management, after prevention, is identification.

Strategies to Identify Lame Cows

It is important for a producer to identify lame cows and treat them in a timely manner. Even with all the known negative effects of lameness for the cow and the producer, lameness remains a common issue on dairies today.

Due to the level of subjectivity and difficulty of identifying lame cows, many cases may go unnoticed by producers. Cows are prey animals making them very good at hiding the injury or pain that is associated with lameness. However, as the pain worsens they can often be found lagging behind the rest of the herd on the way to the parlor or in the milking order, reluctant to stand up when it is time to be milked and spending more time lying than usual. The first step to improving lameness identification is walking through the herd daily and evaluating cows for common changes that occur when a cow is lame. Some common clinical signs to be aware of when observing cows include:

• Changes in gait
• Increased lying time
• Decreased dry matter intake
• Weight loss
• Changes in posture and body movements
• Changes in weight distribution

Moving cows to and from the parlor is a good time to observe changes in gait and body movements. Locomotion scoring is a tool that is commonly used to assess gait and posture by assigning a score to each cow as they walk across a flat surface. When used regularly, this scoring system can be used to keep records of the herd so when a cow's locomotion score changes, further evaluation can be performed to find what could be causing the change in gait. The five-point locomotion scoring system developed by Sprecher et al. (1997) is the most frequently used method in lameness research. When using this system, a score of 1 is normal; this is when the cow stands and walks normal with a level back and makes long, confident strides.  A score of 5 is severely lame with pronounced arching of the back, reluctance to move, and with almost complete weight transfer off the affected limb (Image 1). However, with any scoring system subjectivity between scorers exists and often leads to underreporting of lame cows in the herd.

Inconsistencies in gait scoring amongst producers and researchers has encouraged the exploration of automatic lameness detection. Some automatic lameness identification methods include weighing platforms, pressure-sensitive mats, video analysis, and accelerometers. Using automated detection could facilitate improved lameness management especially in the mild to moderate lameness cases that are often overlooked. The time from lameness onset to treatment may be reduced with automatic detection, therefore, preventing the cases from becoming severe, speeding up recovery, increasing production, improving profitability, and improving cow welfare (Groenevelt et al., 2014).

Lying behavior is the most common variable studied in relation to lameness detection research. Cow-attached sensors or accelerometers can measure lying behavior and activity when attached to the leg and can track rumination and eating when attached to the neck (Image 2).  These types of sensors are also widely used for heat detection. When a cow is lame, they tend to lie down for longer durations and have fewer lying bouts throughout a day. Other activity indicators of lameness that can be tracked with accelerometers are decreased eating time (Grimm et al., 2019), shorter eating bouts (Nechanitzky et al., 2016), step count (Byabazaire et al., 2019), altered ratio of daytime to nighttime activity (Schindhelm et al., 2017), and having a slower reaction when feed is delivered (Weigle et al., 2018).

How detailed the assessment of a cow's activity or behavior is dependent on the resolution of the accelerometer, with a resolution of less than 10 Hz being low and a resolution of 400 Hz being high. High resolution means a more detailed assessment of a cow's gait is produced. Some researchers have reported that gait variables that are measurable by accelerometers are more reliable indicators of lame cows compared to lying behaviors. Gait variables include walking speed (Beer et al., 2016), stride distance (Alsaaod et al., 2017), weight shifting while standing (Thorup et al., 2015), foot placement, and foot lifting duration. The data collected from the accelerometer will be uploaded to a computer and can form daily or weekly behavior and gait summaries for each cow.  Once these summaries are evaluated, discrepancies in behavior, and gait between days and weeks can be identified. A good practice is to visually assess the cows that are appearing lame via the accelerometer summary to verify the technology is working properly. Cow monitoring solutions are available commercially for producers through various precision dairy technology companies. On-farm application of accelerometer technology may be difficult due to costs associated with purchasing the equipment, but if used to aid in heat detection and lameness detection it could encourage more adoption of the technology by producers.

Recordkeeping, whether it is automatic or on paper, is an important aspect of lameness management. PCDART ^® offers an app, PocketDairy ^®, that can be downloaded onto your cell phone or tablet that allows you to access your herd health records on the go. When walking through the barn or pasture observing cows, notes can be added to flag a lame cow. That information will then be transferred to your PCDART account on the computer so you can access that information and monitor lameness problems in your herd. Paper record-keeping is an effective method for monitoring lameness problems as well. Keeping detailed records during hoof trimming for each cow is essential.  Be sure to include cow ID, the affected leg, area of the claw affected, what is causing the lameness, and any treatment that was given. Working closely with a veterinarian and hoof trimmer is helpful for preventing and resolving lameness issues in the herd.

Once lame cows are identified as lame, timely treatment of the affected animal is important. The cost of treatment, inadequate facilities, lack of specific skills, and labor and time involved in the treatment of lame cows may deter producers from treating mild to moderate cases of lameness as they may be considered non-urgent (Horseman et al., 2014). However, prompt treatment and re-checking after treatment of lame cows can prevent the case from becoming more severe, resulting in a shorter duration of lameness, less recurrence of lameness, improvement in cow welfare, and ultimately decreased economic loss associated with lameness

Summary

Early identification and treatment of lame cows is an important lameness management practice and can help reduce the direct and indirect costs associated with lameness cases. The strategies discussed in this article are tools that can be used by producers to define, record, and monitor herd lameness. For information about strategies to prevent lame cows refer to Impacts of Lameness – Part 1: Strategies for Preventing Lame Cows.

References

Alsaaod, M., M. Luternauer, T. Hausegger, R. Kredel, A. Steiner. 2017. The cow pedogram—Analysis of gait cycle variables allows the detection of lameness and foot pathologies. J. Dairy Sci., 100:1417-1426.

Beer, G., M. Alsaaod, A. Starke, G. Schuepbach-Regula, H. Müller, P. Kohler, A. Steiner. 2016. Use of extended characteristics of locomotion and feeding behavior for automated identification of lame dairy cows. PLoS One. 11: Article e0218546.

Byabazaire, J., C. Olariu, M. Taneja, A. Davy. 2019. Lameness Detection as a Service: Application of Machine Learning to an Internet of Cattle. 16th IEEE Annual Consumer Communications & Networking Conference (CCNC), IEEE (2019), pp. 1-6.

Grimm, K., B. Haidn, M. Erhard, M. Tremblay, D. Döpfer. 2019. New insights into the association between lameness, behavior, and performance in Simmental cows. J. Dairy Sci. 102: 2453-2468.

Groenevelt, M., D.C.J. Main, D. Tisdall, T.G. Knowles, N.J. Bell. 2014. Measuring the response to therapeutic foot trimming in dairy cows with fortnightly lameness scoring. Vet. J., 201: 283-288.

Horseman, S. V., E. J. Roe, J. N. Huxley, N. J. Bell, C. S. Mason, H. R. Whay. 2014. The use of in-depth interviews to understand the process of treating lame dairy cows from the farmers' perspective. Anim. Welf. 23: 157-165.

Nechanitzky, K., A. Starke, B. Vidondo, H. Müller, M. Reckardt, K. Friedli, A. Steiner. 2016. Analysis of behavioral changes in dairy cows associated with claw horn lesions. J. Dairy Sci. 99: 2904-2914.

Schindhelm, K., I. Lorenzini, M. Tremblay, D. Döpfer, S. Reese, B. Haidn. 2017. Automatically recorded performance and behaviour parameters as risk factors for lameness in dairy cattle. Chem. Eng. Trans. 58: 583-588.

Sprecher, D. J., D. E. Hostetler, and J. B. Kanneene. 1997. A lameness scoring system that uses posture and gait to predict dairy cattle reproductive performance. Theriogenology 47:1179-1187.

Thorup, V.M., L. Munksgaard, P.E. Robert, H.W. Erhard, P.T. Thomsen, N.C. Friggens. 2015. Lameness detection via leg-mounted accelerometers on dairy cows on four commercial farms. Animal. 9: 1704-1712.

Weigele, H. C. C., L. Gygax, A. Steiner, B. Wechsler, J.-B. Burla. 2018. Moderate lameness leads to marked behavioral changes in dairy cows. J. Dairy Sci., 101: 2370-2382.