THE EFFECTS OF SEASON AND LACTATION NUMBER ON THE COMPOSITION OF HOLSTEIN CATTLE RAW MILK IN TURKIYE

This study was conducted to determine the somatic cell count for 210 milk samples taken Holstein Friesian cows in quarterly periods according to season and lactation order in a private dairy cattle farm in Diyarbakr province, Turkiye.The effects of lactation order and season were analyzed using the Least Squares Method, with multiple comparisons conducted using Duncan's test.The average fat, protein, dry matter, lactose, and SCC contents of raw milk samples throughout the year were determined to be 3.61%, 3.22%, 12.71%, 4.68%, and 211.70 cells/ml, respectively.The study found statistically significant differences between lactation orders in terms of fat, dry matter, protein, and SCC contents, while no significant differences were observed in lactose content.Significant and positive correlations were detected between lactation order and both dry matter (r = 0.383, p < 0.001) and SCC (r = 0.355, p < 0.001).There were negative correlations observed between season and both milk fat (r = -0.333,p < 0.001) and SCC (r = -0.333,p < 0.001).A negative correlation was also found between season and dry matter (r = -0.278,p < 0.001).As a result, lactation order and season have significant effects on milk composition and somatic cell count.