Features of formation of selection groups of cows

Effective use of highly productive animals pro-motes the improvement of genealogical structure of breeding herd and breed, accumulation of valuable genetic potential in the subsequent generations, increases the chances of receiving even more high-ly productive and valuable potential in coming gen- erations, makes chances in obtaining even more highly productive and valuable cattle in pedigree terms. The object of the researches was the live- stock of cows of Simmental breed numbering 1300 heads bred in APC "Tavolzhan". Productive quali-ties of cows, selection criteria of animals in selec-tion group were studied and defined and its charac-teristic was given. As the result of conducted re-searches it was revealed that selection group dif-fered in high rates on the yield of milk (9451 kg), milk butterfat (4.53 %). Cows combine high rates of high milk yield and qualitative characteristics of milk. The yield of milk for the last finished lactation of cows of selection group made 8844 kg, fat mass fraction was 4.46 % and the mass fraction of pro-tein was 3.37 %. The selection differential between the selected group and average value of the sign on herd made 2411.25 kg on the yield of milk; 0.078 % for butterfat and 0.025 % on milk protein. In the analysis of interrelations it was revealed that between the yield of milk and mass fraction of fat in milk there was weak negative interrelation. Be-tween the yield of milk and mass fraction of protein in milk weak positive interrelation, correlation coef-ficient between these signs equal to 0.21 was not-ed. Between the yield of milk and the amount of milk fat and protein strong correlation interrelation was noted, the coefficients of correlation were equal to 0.84 and 0.90 respectively. The amount of milk fat and protein can be used as selection in-dexes the selection on which will allow improving the indicators of dairy efficiency of cows in herd. Thus, when forming selection group in herd of cat-tle it is necessary to adhere to the general require-ments at selection of animals for the constitution and the exterior: typical features of breed, strong constitution, the lack of the defects causing the de-crease in the efficiency, the hollowness of back and loins, pelvic narrowness, interception behind shov-els, weakness of limbs, general weakness of the constitution, roughness, overdevelopment, etc. The main selection criterion of cows in selection group is the excess of average value of the yield of milk on herd in the selected group for 27 % and more.