Association between Clinical Mastitis and Zootechnical Performance in Algerian Dairy Cows

Clinical mastitis is one of the most important diseases in dairy cattle. This research aimed to assess the prevalence and risk factors of clinical mastitis, as well as to estimate their impact on the zootechnical performance of dairy cows.

The data was collected from 1134 lactations among 288 cows with clinical mastitis during the reference lactation, between 2019 and 2022.

The prevalence of clinical mastitis was 12.2% and this increased with the parity. The cows in 2^nd, 3^rd and 4^th lactation had prevalence rate of 10.7%, 12.3% and 18.8% respectively, compared to 7.3% in cows during their 1st lactation (P<0.05). Similarly, the incidence of clinical mastitis varied significantly with the calving season and the calving year (P<0.01). The clinical mastitis had a significant impact on reproductive performance; including days open (DO), conception rate at first service (CRF) and services per conception (SPC) (P<0.05). Furthermore, clinical mastitis had a significant negative impact on the dairy production performances (P<0.05). The cows with mastitis produce 321.2 liter of milk and 19.1 kg of fat, less than the cows that had no evidence of mastitis. In conclusion, Clinical mastitis continues to have a negative impact on the performance of dairy cows. It is recommended to support research for the development of new tools for early diagnosis and treatment of the disease in Algeria.