Transferrin Polymorphism versus Growth Rate in Lambs, Polish Long-wool Sheep – I. Frequency of genes and genotypes of transferrin in flock of Polish Long-wool Sheep
Abstract. The subject of this study was to identify the transferring polymorphism and analyse changes in the frequency of alleles and genotypes of the transferring in a flock of Polish long-wool sheep on the grounds of lambs from the four subsequent years. The flock comprised 3419 lambs, either sex, from the four subsequent lambings, (i – 920 off, ii – 849 off, iii – 914 and iv – 736 off accordingly). The separation of transferring variants was done using starch gel electrophoresis. The significant increase in the frequency of BD transferring phenotype was observed, CC and CE phenotypes, however, decreased and the frequency of Tf BD phenotype gradually dropped. The flock selected for quality traits exhibited a significant growth in the frequency of TfD allele in subsequent years of the study, whereas the frequency of TfC allele decreased. The frequency of remaining alleles varied in certain years of the study and no distinguished changes were found. The homozygosity of the polymorphic transferring noted in the first year. Regularities of changes in the frequency of phenotypes and alleles of transferring in the flock concerned could mark changes in the breeding – selecting scheme.