DYNAMICS OF THE LIVE WEIGHT OF THE TUSHINO SHEEP’S OFFSPRING DEPENDING ON THE AGE OF THE PARENTS
It is necessary to consolidate the hereditary properties of breeding sheep through the rational use of genetic resources and the intensification of the breeding process based on the age of parental pairs for elimination of the negative impact on the Tushino sheep’s inbreeding. 4 different-age groups of female sheep of the Tushino breed (300 heads in each) were formed on the basis of the JSC Prigorodny district (the Republic of North Ossetia-Alania) in 2019. All sheep met the requirements of the first class. The groups consisted of 1) ewes (1.5 years old); 2) (2.5-3.5 years old); 3) female sheep (4.5-5.5 years old); 4) female sheep (6.5 years old and older). Also there were 9 rams of different ages - three heads in each group (1) 1.5 years; 2) 2.5-4.5 years; 3) over 6.5 years). Live weight was determined by individual weighing at birth with accuracy of 0.1 kg and up to 0.5 kg in other periods. Absolute and relative gain data were calculated on the basis of live weight data. Lambs which were obtained from 3.5-4.5 year old female sheep had the highest live weight at birth. Ewes and rams from middle-aged and older female sheep developed well up to the age of 6.5 months. However there was no significant difference in the weight of the offspring depending on the age of female sheep by the age of a year. The age of the fathers had little effect on the weight of the lambs at birth and to beating. By the age of one year, the rams had larger offspring from 5.5-year-old and older rams. A significant difference was obtained. Taking into account different age combinations of parents, mating is the best for both rams and ewes >2.5-4.5 x +4.5-5.5 years. From the mating of the same age old and especially young parents, offspring with the lowest live weight was obtained.