Genetic-statistical options of pure-bred and crossbred sheep

The results of the research on determination of genetic options of productivity are presented in the article, and the definite directions of their use in seep selection are justified under pure-bred fine-fleece sheep breeding, as well as their crossing with Semi- fine-fleece producers. The researched material was presented by fine-fleece ewes of “Perekosˮ breed of different interbreed types (meat-wool and wool-meat), and rams of “Perekosˮ breed, as well as “Kuibyshevskayaˮ and “Romney-Marshˮ in the herd of cooperative farm “Vokhodˮ in Michurinsk area, Tambov region. The experiment determined high va riability, freq-uency, nerita bility and correlation of main indicies of productivity in pure-bred, animals, and in the cross-bred animals with “Kuibyshevskayaˮ and “Romney-Marshˮ breeds. The coefficient of live-weight frequency at birth and at the 12-month age in cross-beeds was aboit 0.89 and 0.75, it is veraciously more than 0.24 and 0.10 as compared with pure-bred anologues. The information on heritability coefficients of three main indicies of productivity makes it possible to conclude, that the most heritability correlates with the wool Shearing with the minimal index in pure-bred animals of 0.576, and maximal in cross-beed with “Romney-Marshˮ about 0.872. The correlation coefficient between live weight and wool shearing was higher in rams from ewes of meat-wool type and producers “Romney-Marshˮ, which was 0.844, that is 0.081 higher as compared with animals from wool-meat type eves. The higher indices of variability and heritability of live weight, length and wool shearing in experiment animals of pure-bred type as well as in cross-bred animals allow the effective selection according to these indicators. The high positive correlation between them will allow the affective selection according to these indicators. The determined high coefficients of indicators frequency of productivity will allow predict in early aga their importance in one-year age, and help more effective breed selection.