Thaaer Abdullah Khaleel; Dhafer S. Abdullah; Hadeel A. Omear
Volume 24, Issue 1 , March 2024, , Pages 238-245
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 ...
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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.
Thaaer Abdullah Khaleel; Dhafer S. Abdullah; Hadeel A. Omear
Volume 23, Issue 4 , December 2023, , Pages 35-42
Abstract
The research was conducted at the Khalis cows station in Al-Khalis district - Diyala Governorate and the central laboratory of the Faculty of Agriculture - University of Tikrit for the period from 13/12/2020 to 1/2/2022, a sample of 63 Holstein cows, with the aim of extracting the genetic ...
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The research was conducted at the Khalis cows station in Al-Khalis district - Diyala Governorate and the central laboratory of the Faculty of Agriculture - University of Tikrit for the period from 13/12/2020 to 1/2/2022, a sample of 63 Holstein cows, with the aim of extracting the genetic material and determining the genetic polymorphism of the SCD1 gene and its relationship to reproductive traits in Holstein cows, studying the percentage of distribution of genetic structures in the cows that were studied, the allele frequency and calculating the value of chi-square (χ2) were determined. The genotypes frequencies for the SCD1 gene in the studied cow samples were 47.62, 46.03 and 6.35% for AA, AV and VV genotypes respectively. The value of the chi-square (χ2) was highly significant (P < 0.01). The frequency of allele A and V were 0.71 and 0.29 respectively. Some reproductive traits were significantly affected by the different genotypes of the SCD1 gene. Cows with the genotype AA achieved the highest Days Open (106.70 ± 5.84 days), while the genotypes VV and AV were 105.93 ± 14.25 and 92.82 ± 5.89 days respectively. The cows with AA genotype was the highest calving interval (389.77 ± 5.90 days), while the cows of the VV and AV genotypes reached 386.75 ± 14.39 and 374.27 ± 5.96 days respectively. It can be concluded by studying the genetic polymorphism of the SCD1 gene that it is possible to improve the reproductive traits in cows. We also recommend applying the study to a larger sample for several seasons and different locations of the gene, while studying more economic characteristics to give more accurate results for the application of the selection and exclusion strategy.
