GENETIC STRUCTURE OF THE SHEEP FROM THE SHUMEN INBREEDING TYPE OF NORTH-EAST BULGARIAN MERINO SHEEP
Nevyana Stancheva, Genoveva Staikova, Teodora Angelova, Petia Slavova, Jivko Krastanov, Daniela Yordanova, Georgi Kalaydhziev
Abstract: Objective of the study was to establish the present genetic and age structure in the only one at the national level sheep from the nucleus herd of the North-east Bulgarian merino sheep, raised in the Experimental Station of Agriculture – Targovishte, from the Agricultural Academy. Subject of the study are the ewes born during the period 2008–2012 with available records for the main selection traits – wool yield, live weight and prolificacy. On the basis of the information from the pedigree books was build up a database of the pedigrees of 584 ewes. For each individual was constructed a genetic code representing the breed belonging of the ancestors back to third pedigree level. The established
genotypes are formed with the participation of the breeds: 1 – North-east Bulgarian merino sheep; 2 – Australian merino; 3 – Booroola; 4 – with unknown pedigree. Based on the obtained information the genotypes of individuals and the number of individuals with similar genotypes in the herd are established. Depending on the blood of individual breeds the genetic groups in the herd in genotype of each animal were determined. For the particular period of study, the genetic structure of the herd is formed by 41 genotypes with different breed combinations. Pure-bred animals from breed occupy 20.3% from the structure of herd. Ewes, product of internal linear breeding, with a component of the Australian merino in genotype constitute 59% as their individual variations are distributed in the range from 0.6% to 11.4%. Estimated overall rate (7.2%) of the animals from North-East Bulgarian merino sheep with component from Booroola breed in genotype is distributed in the range from 0.3% to 3.28%. Animals whose genotypes were formed with the participation of all three breeds occupy 7.5% from the total herds.
genotypes are formed with the participation of the breeds: 1 – North-east Bulgarian merino sheep; 2 – Australian merino; 3 – Booroola; 4 – with unknown pedigree. Based on the obtained information the genotypes of individuals and the number of individuals with similar genotypes in the herd are established. Depending on the blood of individual breeds the genetic groups in the herd in genotype of each animal were determined. For the particular period of study, the genetic structure of the herd is formed by 41 genotypes with different breed combinations. Pure-bred animals from breed occupy 20.3% from the structure of herd. Ewes, product of internal linear breeding, with a component of the Australian merino in genotype constitute 59% as their individual variations are distributed in the range from 0.6% to 11.4%. Estimated overall rate (7.2%) of the animals from North-East Bulgarian merino sheep with component from Booroola breed in genotype is distributed in the range from 0.3% to 3.28%. Animals whose genotypes were formed with the participation of all three breeds occupy 7.5% from the total herds.
Keywords: genetic group; genetic structure; genotype; North-east Bulgarian merino sheep; sheep
Date published: 2018-05-28
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