Peculiarities and differences of Žemaitukai and large-type Žemaitukai horse genotypes

Abstract

Blood samples from 232 Žemaitukai and 190 large-type Žemaitukai horses were analysed at the Blood Typing Laboratory of the Institute of Animal Science of Lithuanian Veterinary Academy to carry out the blood group and protein polymorphism studies. Sixteen and 19 alleles in Žemaitukai and large-type Žemaitukai blood samples, respectively, were found in three blood group systems. The corresponding numbers of alleles in three protein polymorphism systems were, respectively, 19 and 20. In the EAD system, 7 alleles were found for the Žemaitukai breed and 10 for the large-type Žemaitukai breed. Alleles Ddghm and Dad are most typical of Žemaitukai and alleles Ddl, Dcgm and Ddk of large-type Žemaitukai. In the EAQ system, the Qc allele typical of both breeds was detected. Alleles Dcdf, Ddfh and Dcfgm were found in the Žemaitukai breed. Th ere were signifi cant diff erences between the breeds in all (Al, Es, Tf) protein polymorphism systems. A tendency towards a lower total homozygosity was found in the Žemaitukai breed after comparing the data of 2000 (36.22) and 2008 (33.56). Total homozygosity increased in the large-type Žemaitukai population from 33.41 in 2000 to 35.94 in 2008. Blood group homozygosity in both breeds was lower than that of blood protein. The study revealed a reduced genetic similarity (r) between the breeds. According to data of 2000 and 2008, the genetic similarity (r) was, respectively, 0.6513 and 0.5785. The genetic similarity between the breeds by the blood group systems was found to be higher (0.8421) and that by the blood protein systems lower (0.6870). Keywords: blood groups, protein polymorphism, genetic similarities