Prevalence of sub clinical mastitis in cows: Its etiology and antibiogram

Study was planned to determine the prevalence of sub clinical mastitis in crossbred and indigenous cows and to characterize etiological agent/s involved along with their antimicrobial sensitivity testing. Milk samples from 364 quarters of 95 lactating cows at an organized farm were screened. The overall quarter wise and animal wise prevalence on the basis of cultural examination was 64.21 and 39.83%, respectively. According to International Dairy Federation criteria, 15.38% quarters of cows were suffering from sub clinical mastitis on account of having somatic cell count (SCC) more than 5,00,000 per ml of milk and culturally positive. The prevalence of latent mastitis (SCC < 5 x lOS/ml and culturally positive) and non-specific mastitis (SCC > 5 x lOS/ml of milk and culturally negative) was observed as 24.45 and 4.67%, respectively. A total of 150 organisms were recovered out of 145 culturally positive quarters. These were 38.66% coagulase positive staphylococci and 29.33% were coagulase negative staphylococci followed by Streptococcus dysgalactiae (22.66%), Streptococcus agalactiae (6.66%) and Streptococcus uberis (2.66%), and (3.33%) quarters revealed mixed infections of Staphylococcus spp. and Streptococcusspp. The antibiogram of isolates revealed 100% sensitivity to Cloxacillin, Ceftriaxone and Cefoperazone and high (90.90–100%) sensitivity towards Enrofloxacin, Cephalexin, Gentamicin and Lincomycin.