The study was conducted to determine the effect of non-genetic factors on Sub-Clinical Mastitis (SCM) and to investigate the relationships between these factors with Somatic cell count (SCC) in Tharparkar Cattle raised at Livestock Research Center, Chandan, Jaisalmer in Thar desert of Rajasthan, India. Quarter wise milk samples were collected and examined by somatic

cell count to check the status of subclinical mastitis. Data were collected from the record register maintained at farm and data evaluated by Parity, Stage of Lactation and Season of calving by the SPSS packet program. On analysis of variance result revealed that the parity had highly significantly (P<0.01) effect on SCC. Higher incidence of SCM was in later parities in comparison to primiparous animals. No statistical difference was found between different stages of lactation. Season of calving had significant (P<0.05) effect on SCC. Lower incidence of SCM and SCC were revealed in summer and winter season of calving as compared to the autumn and rainy season of calving groups. So it can be concluded from the present study that the non-genetic factors like parity, stage of lactation and season of calving have a significant effect on Milk SCC. Thus, dairy farmers are advised to spend more time on their herds and given extra care to their animals in later parity stage, early stage of lactation and in the autumn or rainy season of calving to prevent the infection of sub-clinical mastitis.