Health Status of Skopelos Goats and Its Impact on Milk Yield Under Intensive and Extensive Farming Systems

Health and welfare are fundamental to goat production; however, their impact on milk yield in goats reared under different farming systems remains insufficiently studied. The objective was to examine the frequency of various health issues in dairy goats reared under two different farming systems and to assess their effects on daily milk yield (DMY). A total of 286 Skopelos goats from an intensive (N_A = 153) and an extensive (N_B = 133) farm, all with the same genetic background, were prospectively monitored for two consecutive lactation periods. Each goat was clinically examined for animal-based health indicators every 50 days, while individual DMY was also recorded. Morbidity frequency measures (cumulative incidence, point, and period prevalence) were calculated for each one of the studied health issues, and mixed linear regression models were developed to assess the effect of each one of the studied health issues on DMY. The results indicated that overgrown hooves were more common in intensively reared goats, while anemia and nasal discharge prevailed in extensively reared goats. Udder asymmetry, udder fibrosis, body abscesses, poor hair coat quality, and swollen lymph nodes were common in both farms, albeit more prevalent in extensively reared goats, except for udder asymmetry. Among the studied health issues, lameness (18.5%, p < 0.05), mouth lesions (14.1%, p < 0.05), udder asymmetry (6.6%, p < 0.001), and udder fibrosis (9.5%, p < 0.001), were significantly associated with reductions in DMY. These findings provide valuable insights for optimizing herd health management practices in dairy goats based on evidence and farming system requirements.