The article presents the results of physiological research carried out in a large sheep farm in the arid zone of southern Russia to study the manganese metabolism of single ewes of the Kalmyk breed and to establish their needs for this element by a factorial method of research. A scientific justification is given for optimizing the ration of manganese in single mutton ewes. The dynamics of the manganese content in the organs and tissues of the sheep and the organism of single mutton ewes for the first time have been revealed. Considering the physiological state of the ewes, the real daily requirement of the ewes in the studied microelement and the degree of its assimilation from the diets have been determined. It has been established that the intensity of manganese metabolism in the organism of fat-tailed ewes has been considerably increased during the non-dairy period and the distribution of manganese in their bodies has not been even. It has been higher in udder, uterus, chyme, omasum, and liver, and lower – in the fat of sheep's tail, blood, and internal fat.
The factorial method about endogenous losses in feces and urine has been used to determine the daily requirement of manganese in the dry weight of single fat-tailed sheep. The daily requirement is 82 mg per head per day, or 50.3 mg/kg of dry substance of a diet and 1.44 mg/kg of live weight of an ewe.