Productivity of offspring of various origin depending on the level of feeding of ewes and morphofunctional features of their placenta

Abstract

The paper presents the material of scientific and production experiments on the crossing of stud rams of the North Caucasian mutton-wool breed with fine-fleece ewes with different levels of their feeding in the second half of the pregnancy. It has been found that the use of North Caucasian mutton-wool sheep on fine-fleece ewes contributes to an increase in the fertilizing capacity, fertility and milk production of the breeding stock, an increase in the survival rate of offspring, which is confirmed by the best morphometric indicators of the placenta of the crossbred progeny. Crossbred offspring from semifine-fleece rams had a higher live weight at birth, at 21 days, at 4 and 13 months of age. They were also characterized by higher quantitative and qualitative indicators of wool productivity. All of the above indicators increase with improved feeding of the ewes in the second half of pregnancy. As a result, raising both purebred and crossbred animals from birth to 13 months of age, while improving the feeding of the ewes in the second half of the pregnancy, increases the indicators of economic efficiency, taking into account the fertility of the ewes, the survival rate of lambs, the increase in live weight gain and the amount of washed wool. The use of morphometric parameters of the placenta allows for early prediction of the productivity of offspring of various origins.