ENVIRONMENT INFLUENCE ON SHEEP PRODUCTIVITY ON THE EXAMPLE OF EXPERIMENT WITH TWIN LAMBS

Abstract

Genetic and phenotypic factors play a certain role in making productivity of sheep. Knowing the influence level of these factors on the animal body makes it possible to predict the results of external factors more accurately. Taking this into account, our experiment in rearing twin lambs of Tsigai breed under different feeding conditions was carried out. When forming experimental groups, only lambs from twin litters were selected. Lambs were tagged and weighed at birth. They were with ewes up to 4 months of age. After weaning, the twin lambs were divided: one lamb was placed in the conditions prevailing on the farm; the second - with improved feeding conditions. In total, there were 60 rams and 32 ewes in the experiment. The experiment lasted 10 months. The animals were weighed and the amount of wool shorn was determined at the age of 4 and 14 months. It was found that twins who are smaller at birth do not compensate for intrauterine development at 14 months of age. It was established that the selected traits (shorn wool, body weight) are more susceptible to the influence of external factors compared to qualitative traits. It was revealed that the mechanism of changes in sheep shearing is associated with the diameter of wool fibers. The correlation between body weight of a ram at weaning and shearing is small: from -0.01 with improved feeding and up to +0.01 with a farm ration. The correlation for ewes was 0.13 and 0.23, respectively.