An assessment on Hemoglobin polymorphism in Nigerian indigenous small ruminant

Abstract

Ojundo Okonkwo and Arebu J. Clinton

Hemoglobin polymorphism was studied in the Nigerian indigenous small ruminants. The populations studied comprised of 50 West African Dwarf (WAD) sheep and 150 red sokoto (RS) goats. Blood samples collected from the animals by jugular venipuncture were subjected to starch gel electrophoresis to reveal the activities of hemoglobin (HB). The acetate strip exposed only two codominant alleles (A and B) that gave rise to three phenotypes (AA, AB and BB) in the sheep population. Three co-dominant alleles producing four phenotypes (AA, AB, BB and AC) were detected among red Sokoto individuals. The frequencies of allele A and B were 0.61 and 0.40 respectively in the WAD and 0.27, 0.72 and 0.003 corresponding to allele A, B and C, respectively, in red Sokoto goats. In the later, 58% and 42% of the individuals were heterozygote and homozygote, respectively. Genotypic frequencies for AA, BB and AB in rams were 0.40, 0.25 and 0.35 respectively and 0.40, 0.10 and 0.50, respectively, in the ewes. Estimated heterozygosities that represent the proportion of the population that is heterozygote were 0.47 and 0.48 in the red Sokoto goats and WAD sheep population, respectively. The observed gene frequencies deviated significantly from the theoretical HardyWeinberg’s proportion.