Effect of Insulin on Yield and Composition of Milk of Dairy Cows

Open Access
Publisher Website
Google Scholar
Abstract
Short-acting insulin injections into lac- tating Holstein cows resulted in a decrease in milk production, milk lactose percentage, and blood glucose levels, and an increase ill the percentage composition of milk fat and protein. The casein expressed as a percent- age of the total protein remained the same during the insulin treatment as compared to the pretreatment period. Phlorizin caused a decrease in milk production, a slight increase in milk fat percentage, but no change in the milk protein percentage. Infusion of glucose with the insulin injec- tions restored the nfilk yield to near-normal levels and caused the milk protein per- eentage to return to the pretreatmeut levels. The milk fat percentage remained elevated during the glucose infusion. Increases in milk fat and protein percentages during in- sulin treatment cannot be explained en- tirely by a decrease in the volume of milk.