Mastitis is an expensive disease in dairy breeding and efficient early detection of this disease is one of the keys means to reduce its effects. The purpose of this study was to evaluate the electrical conductivity (EC) of milk as a subclinical mastitis indicator in dairy cattle, in the southern region of Souss-Massa, Morocco. The study was done on 191 cows belonging to 11 dairy cattle farms. The EC test using predefined thresholds showed that 67 % of quarters are healthy, 20 % have a risk to develop the disease and 13 % are infected. The analysis of 247 milk samples has highlighted the effect on the EC of lactation number and thereby 25.6% of infected quarters belong to cows on their fifth lactation number. The quarters of cows that are on their first lactation are healthy. It has also been observed that the age of cows had an effect on the disease appearance. Regular inspection of herds showed that inappropriate hygienic conditions constitute one of the risk factors to develop mastitis. Regarding treatment, we also noticed the high efficacy of antibiotic to stop disease development and decrease the EC values. The EC measurement seems to be an interesting tool that needs to be further developed in the region for routine and regular screening in integrated program against mastitis.

Keywords: Cattle, mastitis, milk electrical conductivity, early screening, Morocco.