Comparative characteristics of population and genetic parameters of Syrian cattle breed Shami with Holstein and Aberdeen-Angus

Abstract

The material on the widespread use of Holstein cattle breed in the Syrian Arab Republic to improve local breeds has been presented in the article. The analysis of the genetic equilibrium of individual loci in Syrian cattle breed Shami has been revealed a deviation from the equilibrium of four loci: TGLA227, SPS115, TGLA122 and ETH225, in Holstein breed one locus SPS115, in Aberdeen-Angus breed two loci TGLA122 and ETH225. When assessing the level of genetic consolidation, a defi ciency of heterozygotes has been noted in two of the three breeds studied: 4,8 % in Shami and 8,0 % in AberdeenAngus. In Holstein breed a slight excess of heterozygotes at the level of 0,2 % has been revealed. The calculation of the value of the fixation index (Fis) has shown an excess of heterozygotes only in the loci TGLA227, INRA23, TGLA126 and as a consequence a positive average value collectively for the studied samples of cattle at the level of 5,8 %. The average Fst at 11 loci for all breeds was 0,069, indicating that 93,1 % of all variability is due to intra-breed diversity and only 6,9 % to inter-breed differences. The analysis of animals belonging to their own breed has shown 100 % genetic consolidation and compliance of the studied individuals with their breeds. The analysis of genetic distances adjusted for small samples has revealed the smallest genetic distance between Shami and Holstein breeds 0,107. Aberdeen-Angus breed, which has a separate origin and has not been imported into the Syrian Arab Republic, is adjacent to this cluster an independent branch.