EFFECT OF GLYCEROL ON MILK YIELD, ITS QUALITY AND BLOOD PARAMETERS OF HOLSTEIN COWS

The aim of this study was to investigate the effect of adding glycerol at different levels (T1 = control treatment without glycerol, T2 = 75 ml and T3 = 150 ml glycerol) on daily milk yield, milk components and some blood parameters of Holstein cows during the period of 60 days. Milk yield increased significantly (P≤0.05) at 15th day of the experiment, and highly significant (P≤0.01) at 30th and 60th days of the experiment in T3 group. Percentage of milk protein and lactose increased (P≤0.01) in T2 and T3 groups and the percentage of milk fat in the T3 group decreased at day 60 of the experiment. The blood glucose concentration increased (P≤0.01) in T2 and T3 groups at 30 and 60 days of the experiment. Triglyceride concentration increased (P≤0.01) in the blood of T2 and T3 treated cows at day 60. The concentration of cholesterol, NEFA and BHBA decreased (P≤0.01) in T3 treated cows at day 60 of the experiment. The concentration of phosphorous and magnesium were also affected as a result of glycerol treatment. It can be concluded that the addition of dietary glycerol 150 ml / day enhanced milk yield, protein and lactose percentage, and improved blood parameters by increasing blood glucose and reducing NEFA and BHBA concentrations of Holstein cows.