The population-and-genetic characteristics of meat-wool semi-fine-fleece-wool sheep of Pechora pedigree group
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Low positive correlation of body weight with clip and length of wool, high direct correlation with sizes of chest girth, average correlation - with a width of chest, slanting length of a trunk, a width of chest, the height at the withers and the rump are revealed in Pechora meat-wool semi-fine-fleece wool sheep. The calculations showed a high frequency of occurrence of bodyweight at 60 and 180 days (rw = 0.90), the height at the withers (rw = 0.71) and height in the sacrum (rw = 0.73). The measurements at 30 and 180 days width of a breast and a girth of metacarpus added to the above trait. The greatest factor of occurrence for a series of measurements from birth up to 180-day age was at the girth of metacarpus (rw = 0.58). For a flock of sheep in Pechora experimental station the greatest values of coefficients of heritability of lambs-one at birth were on live weight, height in withers, the width of the chest and hip chest. Correlation between the live weight of ewes and lambs in 2-month age without subdivisions on lambs-one and twins is 0.167, and in 4-month age is 0.038. In this case during the growth of the lambs influence of mothers on the further development of the progeny is weakening and the importance of other factors is growing; at the same time the relationship between body weight of lambs, 2- and 4- month ages reaches high values (0.795). Breeding-and-genetic parameters of the population (correlation, repeatability and heritability of morphological and main features of productivity) are within the biological norm. The study of heritability and frequency of occurrence of some morphological characteristics of sheep of Pechora breed group at different ages allows to identify the traits which are the most perspective for the effective selection and organization of early forecast of productivity of sheep. Live weight and height at the withers of lambs in the nursing period are most suitable for forecasting their growth and body type in subsequent ages. The use of these indicators in the first months of life already can be more reasonable to conduct the selection of young promising for herd maintenance and production of the lamb meat. The live weight of lambs in two-month age is most appropriate as a generalized criterion for simultaneous breeding of ewes for increasing milk yield and fertility, as well as a selection of pedigree cattle at an early age for repair broodstock.
Keywords: sheep, pedigree group, genofund herd, breeding, heritability, repeatability, forecast, meat, wool