THE IMPORTANCE OF MONITORING CHANGES IN MILK FAT TO MILK PROTEIN RATIO IN HOLSTEIN COWS DURING LACTATION

Abstract

Milk samples of 24 pure-bred Holstein cows were taken during lactation and changes in milk fat to milk protein ratio and quality of rennet gel were evaluated. The cows were either fi rst (n=12) or second (n=12) calvers, in the same phase of lactation. The individual milk samples were taken on average on the day 25, 45, 73, 101, 133, 166, 199, 224, 253 and 280 of lactation and the following mean values of the F/P ratio were found: 1.91; 1.45; 1.38; 1.28; 1.22; 1.14; 1.26; 1.21; 1.09; 1.18. High values in the fi rst phase suggest a great energy defi ciency. The quality of rennet gel was also worst in the fi rst phase of lactation.

Keywords

• holstein cattle
• milk protein
• milk fat
• quality of rennet gel