Hemoglobin polymorphism in Nigerian indigenous small ruminant populations - preliminary investigation

Abstract

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 co-dominant 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 Hardy-Weinberg’s proportion.