Bacteriological Study of Subclinical Mastitis in Batna and Setif Governorates Algeria

168642 This study focused on the diagnosis of sub-clinical mastitis by the California Mastitis Test (CMT) and bacteriological analysis of milk samples. The identification of the bacterial strains was performed using API systems (API Staph, API Strep, API 20 E). It covered a total of 50 lacting dairy cows in Batna and Setif Governorates. The CMT results showed a positivity rate of 29.44% with a score 1-4 (i.e > 200,000 cells / ml).The bacteriological study revealed the isolation of 89 bacterial strains distributed as follows: 27 strains of staphylococci including 23 coagulase-negative staphylococci (CNS) that are generally implicated in sub-clinical mastitis, 39 streptococcal strains including 10 strains of Lactococcus lactis ssp lactis, 23 strains of Enterobacteriaceae mainly represented by E.coli. The use of the CMT in association with the identification of the pathogenic bacterial strains gives a precise image on the health status of the bovine udder and the appropriate measures to apply to reduce the incidence of mastitis.