Özet:

The aim of our research was to determine the influences of some environmental factors on somatic cell count (SCC) and chemical composition of cow bulk tank milk. A total of 428 bulk tank milk samples of Brown Swiss cows were collected between January and October 2016 from family dairy farms located in Kırşehir province of Turkey. To evaluate the effect of farm scale, daily total bulk tank milk production was classified in three groups (small: <20 lt/d; medium: 20-40 lt/d and large: >40 lt/d). Also, three groups were designed according to average SCC values as low (<200x103 cells/ml), medium (200-500x103 cells/ml) and high SCC (>500x103 cells/ml). SCC was transformed according to the base of log10, because it did not show normal distribution. The results showed that sampling season was significantly affected fat content (P<0.05), logSCC, solids-not-fat (SNF), protein, lactose and pH (P<0.01). SCC was the highest in large-scale farms, while the highest fat content was determined in small-scale farms (P<0.01). Also, the lowest pH was found in large-scale farms compared to small and medium-scale farms (P<0.01). Of all bulk tank milk composition, SCC only affected fat content (P<0.05), and the lowest fat content was determined in bulk tank milk with high SCC (>500x103 cell/ml). As a result, it was concluded that season was primarily responsible among the most important environmental factor to increase bulk tank milk quality.

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