The optimal intake rates of cobalt for lactating meat-greasy ewes were calculated in the context of the arid zone of Russia using a factorial method based on the concentration of this microelement in the organs and tissues, in the chyme, and gastrointestinal tract, as well as the degree of intake of this micronutrient from rations and endogenous losses with feces, urine, and milk. It was revealed that during lactation, the intensity of cobalt metabolism in the body of ewe increased significantly. The daily requirement of lactating ewes in this element, determined in the course of study, was as follows: in the first half of lactation, they had to be fed 1.6 mg of cobalt per head per day, while per one kg of dry matter of the ration – 0.53 mg, and per one kg of live weight – 0.03 mg. In the second half of lactation, these figures should be 1.3, 0.47, and 0.02 mg, respectively.
