RELATIONSHIP BETWEEN TEMPERATURE IN STABLE, MILK COMPOSITION AND TECHNOLOGICAL PROPERTIES OF HOLSTEIN DAIRY COWS

Altogether 87 bulk milk samples obtained in identical herds of Holstein cows within 87 weeks were divided into six groups depending on average diurnal pattern of air temperatures in stable (less than 5.0 degrees C; 5.1 to 10.0 degrees C; 10.1 to 15.0 degrees C; 15.1 to 20.0 degrees C; 20.1 to 25.0 degrees C; above 25.1 degrees C). The average values of milk parameters under study (n = 87) were as follows: fat content 3.98 g.100g(-1), protein content 3.32 g.100g(-1), casein content 2.61 g.100g(-1), lactose content 4.82 g.100g(-1), solids non-fat content 8.74 g.100g(-1), specific density 1.0308 kg.l(-1), titratable acidity 6.91 degrees SH, pH acidity 6.74, rennet coagulation time 201 sec, curd quality class 1.71; average diurnal temperature was 13.27 degrees C. Based on the results can be stated that with the increasing average diurnal air temperature, contents of fat, protein, casein and solids-non-fat significantly decreased (p<0.01). On the other hand, relationship between temperature in stable and lactose, specific density, rennet coagulation time, curd quality, titratable and pH acidity was not statistically significant (p>0.01).