摘要：In high producing dairy animals, especially during early lactation, the amount of energy and protein required for maintenance of body tissues and milk production often exceeds the amount of energy available from diet which results in a negative energy balance. Traditionally, cereal grains have been used to increase the energy density of diet in the ration of high producing dairy cattle, which adversely affect the dry matter intake, depresses fiber digestion and results in milk fat depression syndrome. Another viable option is to supplement protected fat in the diet of lactating cows and buffaloes which positively affect efficiency of these animals through a combination of caloric and non-caloric effects. Caloric effects are attributable to greater energy content and energetic efficiency of lipids as compared to that of carbohydrates or proteins with the overall benefit being increased milk production. The non-caloric effects include improved reproductive performance and altered fatty acid profile of milk. Whereas, the supplementation of protected protein in the diets of lactating animals increases the milk yield due to proportionate increase in the supply of amino acid s to the host postruminally. Feeding protected protein in diets containing supplemental fat may alleviate the decrease in milk protein percentage associated with fat supplementation. Therefore, there is need to avoid negative energy balance during early lactation and to enhance the milk productivity with desirable composition, which will have far reaching benefits on their reproductive performance by supplementation of protected nutrients in the ration of medium and high yielding lactating animals.
