Effects of reducing bypass protein rate and increasing sugar rate in rations of dairy cows in transition period on some yield and metabolism parameters

The majority of the ration in dairy cattle consists of carbohydrates and protein. However, the health and yield performance of animals depends on the harmonious digestion of carbohydrates and protein in the rumen. Nowadays, in order to meet the increasing energy needs of high-yield dairy cattle, rations containing high starch and protein that are not degraded in the rumen. This study examined the effects of reducing the rate of starch and rumen non-degradable protein and increasing the sugar and rumen degradable protein of the diet (isocaloric, isonitrogenous) on milk yield, nutrient composition of milk, and some blood metabolism and immune parameters in transition dairy cows. With such alteration, blood glucose levels in dairy cattle increased before (p<0.05) and blood glucose (p<0.01) and IGG levels increased at birth and after birth (p<0.0001) but NEFA level decreased (p=0.001, p=0.05 respectively), feed consumption increased after birth (p<0.01), milk yield increased numerically and milk fat increased statistically significantly (p<0.01). In addition, blood glucose and BHBA levels were analyzed in very similar patterns, with analyzes performed on the farm using rapid test kits and in the laboratory using cattle-specific kits on the ELIZA reader. As a result, it has been determined that increasing the sugar content and decreasing the bypass protein level in the ration of dairy cattle in the transition period has positive effects on energy metabolism in animals, has the potential to increase milk yield and increases milk fat.