An investigation on somatic cell count in milk samples collected from dairy farms at Tabriz region of Iran

The aim of present study was somatic cell count in milk samples collected from dairy farms at Tabriz region, Northwest of Iran. Three flocks selected based on high productivity and similar characteristics (use of family labour, Holstein herds and average production between upper than 11 kg/cow/day). Milk samples obtained from three parity classes were collect individually from the cows in the second and fifth month of lactation in two seasons: autumn-winter and spring-summer. Results show higher SCC for dairy cattle with second or upper milking. Cows at fifth or upper lactation period had 1000- 5000 ×103 cells/ml commonly but at first lactation there was no any cow with 1000-2500 ×103 cells/ml. In conclusion, incidence of high SCC rate (1000-5000×103) is considerably high during fifth or upper parity but 250 to 750 ×103 SCC cows are considerably low in number compared with first parity cows. Cows at first lactation commonly had 250-500×103 SCC at Tabriz regional farms.