Prevalence, Risk Factors, and Isolation of Primary Causative Agent of Subclinical Mastitis in Dairy Cattle

Subclinical mastitis (SCM) is a prevalent and economically significant disease affecting dairy cattle worldwide. This study aimed to assess the prevalence for SCM in lactating cows across organized and unorganized dairy farms in Mhow, Madhya Pradesh, India. A total of 500 cows, representing non-descript, cross-bred and exotic breeds were screened using the California Mastitis Test (CMT), somatic cell count (SCC) and milk pH analysis. The results indicated an overall SCM prevalence of 33.40% at the animal level and 14.25% at the quarter level. The highest prevalence was observed in cows aged 5-7 years (41.94%) and cross-bred cows (39.04%). Seasonal variations significantly influenced SCM occurrence with the highest prevalence recorded during the rainy season (45.50%). Right hind quarters were most frequently affected (16.66%). Cows in unorganized farms exhibited a higher prevalence (38.88%) compared to those in organized farms (26.95%). CMT results categorized 46.26% of positive cases as moderate (2+), while SCC levels were significantly elevated in affected cows (11.18 × 10⁵ cells/ml). Additionally, milk pH was higher in SCM-affected cows (7.00) compared to healthy controls (6.50). Bacteriological analysis of CMT-positive milk samples revealed Staphylococcus spp. as the predominant pathogen. The present study reported that there is high prevalence of subclinical mastitis in dairy cows, which may lower milk production and productivity of animals. Effective management, treatment and veterinary support can help farmers control the disease and minimize losses.