LAMENESS ON SELECTED FARMS IN THE EASTERN CAPE AND KZN

Lameness in dairy cows is usually caused by claw lesions, which include white line disease, sole ulcer, sole haemorrhage, and interdigital difficulties. These lesions are all non-infectious. However, there may also be infectious causes of lameness which are primarily due to bacterial infections affecting the feet and joints, and which are often the most frequent. The consequences of lameness in dairy cows significantly impact their welfare, productivity, and overall health, and most often lead to low feed intake, pain, poor re-conception, reduced milk yield, and consequently premature culling. Studies focusing on lameness in South Africa are relatively scarce. Therefore, the aim of the study cited was to document the prevalence and risk factors commonly associated with lameness in dairy cows, using a sample of farms in the Eastern Cape and KZN.

The study areas were the Adelaide-Alice-Seymour region in the Eastern Cape and the Mooiriver-Howick region in KZN. The computer software systems of four randomly selected dairy farms were used to collect retrospective secondary data for lameness and predisposing factors (2018–2022). The data's targeted parameters included breed, lactation number, weight, stage of lactation, disease diagnosed (lameness), age, and milk production trends.

The highest prevalence was observed in the KZN region (58.8%) compared to the Eastern Cape region (41.2%). Among cattle above nine years of age, the prevalence of lameness was the highest (36%), compared to 7-8-year-old (24%), 4-6-year-old (21.7%), and 1-3-year-old (14.3%) cattle. Additionally, the highest prevalence of lameness was observed during the summer season, followed by spring, winter, and autumn. There was also a significant breed effect (Holstein vs Jersey) and area x season interaction. The strongest association was in the right front leg, followed by the left front leg, right back leg, and left back leg.

Conclusions and recommendations: The regional disparity in lameness rates in the KZN region, which showed a notably higher prevalence than in the Eastern Cape region, probably indicates the impact of environmental differences. The results also revealed significant variations in prevalence across different age groups, with older cattle exhibiting higher lameness rates. Lactation number also played a role, with cattle in their 4th to 8th lactations showing a notable increase in lameness prevalence. Additionally, the seasonal variation in lameness, with higher rates in the summer, underscores the influence of weather conditions as potential triggers for lameness. Additionally, a breed-specific susceptibility to lameness was evident, with Holstein cattle being more prone to lameness than Jersey and crossbred cattle. Lastly, the association between lameness prevalence and days in milk highlights the importance of early detection and management. During the summer months with high rainfall, it is crucial to implement strategies to mitigate wetness and excessive mud, by creating dry bedding areas and installing effective drainage systems. Dry bedding areas are essential for absorbing excess moisture, especially urine, to prevent the formation of mud.