Investigation and Analysis on Subclinical Mastitis of Cow

To seek pathogenic law and provide references in preventing cow subclinical mastitis,60 dairy cows of a dairy farm in Yangling were selected for examining subclinical mastitis with somatic cell count(SCC).The cows were in different parturitions and lactation time,were investigated and analyzed for subclinical mastitis.The results showed that the positive rate of subclinical mastitis was 43.3% in the examined cows.The positive rate was 40.0% in the first to second parturitions cows and 46.7% in the third to fourth parturitions cow.The positive rate was 27.6% in the cows in lactation time less than 200 d,36.4% in 200 d-300 d cows,41.7% in 300 d-400 d cows and 50.0% in more than 400d cows respectively.It suggested that the positive rate of subclinical mastitis would increase with the calving number and lactation time of cows.The husbandry managements and sanitary conditions were also important roles in causing cow subclinical mastitis.