Relationship between the genetic hemoglobin polymorphism, morphometry and fertility of Pramenka sheep breed from central Bosnia

Abstract

Pramenka sheep belong to the group of primitive sheep breeds with a triple-purpose production: milk, meat and wool. None of these production directions is emphasized. Sheep of this breed are the reflection of the environment in which they are located. The characteristics of these sheep are highlighted depth measures of external appearance with modest width measures. Another weaker feature of Pramenka sheep is poor fertility. Despite the mentioned disadvantages, Pramenka sheep is the most grown sheep in Central Bosnia and sheep production is based on it. Methodical selection to improve the characteristics of Pramenka sheep has not applied. However, sheep breeders tend to improve the qualitative and quantitative characteristics of sheep, and that means more intensive work on the selection. In this sense, genetic markers are used to carry out the selection lately. Three types of hemoglobin, HbAA, HbAB and HbBB of Pramenka sheep population (at 189 male and female animals) in Central Bosnia were segregated by the method of electrophoresis. The following genotype frequencies are determined: HbAA 0.11; HbAB 0.41; and HbBB 0.48. Allele frequencies, HbA and HbB for Pramenka sheep breed (estimate based on genotype frequencies) were 0.315 and 0.685. It was found that the population of sheep was in the equilibrium of the frequency of hemoglobin genotypes. Sheep with HbAA genotype had lower morphometric measures in relation to the other two genotypes. The statistically significant difference between sheep with HbAB genotype and HbAA genotype was recorded only for the shin perimeter. The ewes that lambed one lamb have the following frequency of HbAA, HbAB and HbBB genotypes: 0.13; 0.40 and 0.47, and the ewes with twins: 0.02; 0.40 and 0.58. Fertility, as important quantitative characteristic of sheep, was more emphasized in genotype HbBB, than in HbAA genotype. This was confirmed by the statistical analysis.