Some studies on subclinical mastitis in cattle and buffaloes

Abstract

Subclinical mastitis considered one of the most important diseases affecting dairy herds due to its economic and zoonotic importance. The aim of this study: (1) Determination of the prevalence of subclinical mastitis in lactating dairy cows and buffaloes and in the mean time studying the effect of age, number of lactation and stage of lactation on the prevalence. (2) Isolation and identification of causative agents of subclinical mastitis in cows and buffaloes. (3) Evaluation of some screening (diagnostic) tests for the prediction of bacteriological status of apparently normal milk samples collected from apparently healthy udders of cows and buffaloes: a- Direct microscopical somatic cell count (DMSCC). b- N-acetyl-beta-D-glucosaminidase (NAGase) activity. c- Electrical conductivity (EC). d- California mastitis test (CMT). (4) Testing the antibiotic sensitivity pattern of the isolated bacteria (5) Studying the beta-lactamase production by the isolated bacteria. (5) Studying the efficacy of using recent intramarnmary infusion antibiotics (field trials). Examination of324 cows and 45 buffaloes revealed that, 225 (69.4 %) cows and 33 (73.3%) buffaloes were subclinically infected. Prevalence of subclinical mastitis is recorded to be higher in hand milking cows than in machine milking cows (86.5/66.2 %).