Document Type : Articles
Authors
1 a:1:{s:5:"en_US";s:25:"Ministry of agricultural ";}
2 Department of Animal Production, College of Agriculture, Tikrit University, Iraq
3 Department of Biology, College of Science, Tikrit University, Iraq.
Abstract
The research was conducted at the Greater Khalis Cows Station in Diyala Governorate and the central laboratory of the College of Agriculture - Tikrit University for the period from 12/13/2020 to 2/1/2022, on a sample of 63 Holstein cows (dairy), with the aim of extracting the genetic material and identifying the genotypes polymorphism of the gene (FADS2) and the relationship of these genotypes to the characteristics of milk production and its components, as well as the study of the distribution ratios of its structures in the herd, the frequency of the obtained alleles, and the calculation of the chi-square value (χ2). Where the distribution percentage of the genotypes of the FADS2 gene in the cow sample studied was 25.40, 60.32 and 14.28 for the genotypes AA, AG and GG, respectively, the frequency of the A allele was 0.56, while the frequency of the G allele was 0.44 according to the analysis of the FADS2 gene in the study current. The effect of the FADS2 genotypes on the proportions of milk components was significant (P<0.05), as cows with the hybrid genotype AG achieved the highest averages in the ratios of (non-fat solids, protein, lactose), which amounted to (7.79 ± 0.15), (2.85 ± 0.06) and (4.19 ± 0.09) respectively, while cows with a GG genotype gave the lowest averages for the mentioned traits respectively, which amounted to (7.34 ± 0.22), (2.67 ± 0.08) and (3.94 ± 0.13)%, for the FADS2 gene for the studied samples. It can be concluded from the study of genetic variation of the FADS2 gene that it is possible to develop plans for genetic improvement in milk-producing cows.
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