positively and significantly with lactose and phosphorus content,
and negatively with total calcium and citrate content in raw milk
in the present study.
Rajcˇevic´ et al. (2003) reported that a statistically significant
negative correlation occurred between SCC and lactose content in
milk, which was in contrast to the present study. Compared with
former researchers, the significant positive correlation in our results
could be attributed to the different feed, regions and even
milking methods.
3.3.5. Freezing point depression (FPD)
Freezing point depression was significantly higher in winter
than in spring and summer (Table 3) with a range comparable to
that reported by Shipe (1959) – i.e., 515–530 m C. Changes in temperature
and diet were considered to be primarily responsible for
the seasonal effect on milk FPD (Henno et al., 2008). Pinkerton
and Peters (1958) suggested that differences in environmental
temperature and animal feed were contributing factors to the seasonal
variations that they observed. However, Henno et al. (2008)
pointed out that the increase in milk FPD was not caused by the
lack of energy or protein from the feed ration used but was probably
due to the increased water intake with increased temperature
and sunshine hours. No significant correlation between FPD and
compositional parameters was found, which implies that FPD
was a strong independent parameter in raw milk. The freezing
point of cows’ milk is relatively constant as a consequence of osmotic
equilibrium in milk and blood (Shipe, 1959).