Abstract

The study describes the identification of the etiological agents of subclinical mastitis (SCM) among lactating dairy cows under different phases of lactation in an organised dairy farm of Thrissur district, Kerala. The preliminary diagnosis of subclinical mastitis (SCM) was made using California Mastitis test (CMT), a cow side field test. The somatic cell count (SCC) was estimated and the milk samples of affected quarters were subjected to bacterial isolation and identification. The predominant causative agents isolated from milk of cows with SCM were coagulase negative staphylococci (56.25 per cent) followed by S. aureus (25 per cent) and Micrococci spp. (18.75 per cent). Further species identification of the coagulase negative staphylococci revealed that the majority were S. xylosus (28.23 per cent) followed by S. scuiri (15.63 per cent), S. hominis (9.38 per cent) and S. schleiferi (3.13 per cent).

Keywords : California mastitis test, Coagulase negative staphylococci, Somatic cell count, Staphylococcus aureus, Subclinical mastitis