The reproductive problems of high-productive dairy herds represent one global multi factor issue which requires a multidisciplinary approach. The selection of maximal dairy productivity is related to the selection according to some other characteristics such as body condition and increased risk of occurrence of metabolic and reproductive problems of dairy cow breeds. The reproductive system types of dysfunction such as: ovarian cysts, ovarian hypo-function, delayed or absent ovulation etc. are directly caused by metabolic disorders in the body. The metabolic profile is a significant marker of physiological and reproductive status and serves as a diagnosis of many sub clinical diseases. In highly productive cows, measuring the concentration of urea nitrogen in blood and milk provides additional information related to the energy and protein absorption. Preparation and screening samples of milk is far more accessible method than the invasive method for sampling blood, because most researchers suggest routine methods for determining the effectiveness of protein diet while determining the concentration of urea nitrogen and other metabolites in milk samples.