The content of selenium in the milk of the sheep of the Romanovsky breed in different periods of lactation

Purpose: to study the concentration of selenium in milk and the impact of the introduction of selenium preparations on the concentration of a trace element in milk at various periods of lactation at the Romanovskoye sheep in the conditions of industrial complexes of the North-Western region.Materials and methods. 80 disemetals of the Romanov breed aged 1 year are involved. Used clinically healthy animals. The diet was compiled taking into account generally accepted recommendations, depending on age and physiological condition. The content of selenium in plants that were used in the diet of animals was determined by fluorimetrically with 2.3-diaminonaphthalin. At the first stage of the study, a group of disemeters was formed after a backed, milk was received by selecting a control milking after 5, 30, 60, 90, 120th day after the start of lactation. The concentration of selenium in milk was studied by atomic-adsorption spectrometry. At the second stage of the study, two groups of disemeters of the Romanov breed aged 1 year were formed. Pregnancy was confirmed by the visual and evaluation method for the lack of hunting in sheep 20-30 days after the derive period, by the lamb-industry and 2.5 months after the shed period by palpation. During the period of pregnancy, the animals of the first experimental group administered intramuscularly drug “E-sel” at the rate of 1 ml per 50 kg of live weight according to the instructions of the drug; The second group, control, introduced a physiological solution in the same concentration as the drug experimental animals. In animals of the experimental and control groups, a study of the concentration of selenium in milk was carried out by selecting a test milking samples after 5, 30, 60, 90, 120th day after lactation.Results. The concentration of selenium was reduced in various periods of lactation, which is more likely to be associated with a decrease in the total amount of milk produced and the end of the lactation period. In the continuation of the lactation period, the concentration of selenium was lower than reference values. The concentration of selenium in milk was reliably higher in the disetals, which during pregnancy were administered the drug Selena. However, by the second month of lactation, the concentration of the trace element in milk decreased by 47.72 % in relation to the initial period of lactation. It was noted that with the course of lactation and cancellation of the cottage of drugs there is a significant decrease in the concentration of selenium in the milk of the disemets. On the 120th day, lactation concentration of selenium decreased by 5.9 times compared to 5 days of lactation and 4 times for the control group. Thus, it follows that the concentration of selenium in the milk of the disemeters becomes low on the 30th day, therefore, the milk of mothers cannot be a full-fledged source of selenium for growing lambs, since the first, second week after birth was fed exclusively milk, starting from the third week to animals Fertening were introduced, and the lambs were translated to the adult diet only in the ninth week from the moment of birth.