Abstract
The purpose of research – finding the gene associations of growth stages, the characteristics of meat productivity of cattle of the Kazakh white-headed breed and identification of the genotypes that are most promising for the development of genetic markers for economically valuable traits. The blood of the Kazakh white-headed cattle was used as the material of the study. Blood samples and data of zootechnical accounting has been provided by LLP Janibek and LLP Karaman-K, Kostanay region. Determination of animal genotypes by genes of pituitary transcription factor-1 (bPit-1), growth hormone (bGH), growth hormone receptor (bGHR) and insulin-like growth factor-1 (bIGF-1) was performed by PCR-pdrf using endonuclease restriction HinFI, AluI, SspI and SnaBI, respectively. Statistical analysis of genotyping results and zootechnical data was carried out using Microsoft Excel 2010 and Statistica 6.0 programs. The estimation of meat productivity of cattle was carried out on live weight and indexes characterizing a Constitution. The greatest value of the elongation index was observed in animals with genotypes bPit-1-Hinfiav and bPit-1-Hinfiaa. Thus, the index of stretching in cows with genotype bPit-1-HinFIAB is 129.464 (125.000, 132.787), with genotype bPit-1-HinFIAA - 127.966 (125.000, 132.787), while the rate in cows with genotype bPit-1-HinFIBB is 124.167 (111.864,131.026). Polymorphism bIGF-1-SnaBI is associated with the indicator of live weight of the Kazakh white-headed cattle. Thus, animals with the genotype bIGF-1-SnaBIBB at all ages are characterized by reduced living weight compared to animals with genotypes bIGF-1-SnaBIAB and bIGF-1-SnaBIAA. However, the results of the evaluation of the identified preferred and undesirable genotypes in relation to the total sample showed the absence of statistically significant associations with meat productivity.