Evaluation of haemoglobin variants of Red Sokoto goats and Yankasa sheep in Beji, Niger State, Nigeria: Effect on body weight and reproductive parameters

Résumé

Blood was sampled from 76 Red Sokoto (RS) goats and 76 Yankasa Sheep (YS) to evaluate Haemoglobin (Hb) genotypes and their effect on body weight and some reproductive parameters of the animals. The blood samples were analyzed by cellulose acetate electrophoresis. The electrophoretic test revealed the presence of three co-dominant alleles (A, B and C) which produced four haemoglobin genotypes (AA, AB, BB andBC) in RS goats, and two codominantalleles (AandB) which gave rise to two haemoglobin genotypes (AA and AB) in YS. The frequencies of alleles A, B and C were 0.32, 0.61 and 0.07 in RS goats; and 0.945 and 0.055 for alleles A and B in YS. The estimated heterozygosities were 0.406 and 0.118 in RS goats and YS while the estimated inbreeding coefficients were 0.009 and 0.008 in the RS goats and YS, respectively. The observed and expected genotype frequencies deviated significantly from the expected Hardy-Weinberg equilibrium (P 0.05;chi-square=7.82for RS goats, P 0.01;chi-square = 13.13 for YS).There were significant (P<0.05) differences observed in the body weight of male YS as a result of the Hb type; individuals with Hb AB were observed to have higher body weight (44.00 kg) compared to those with Hb AA (22.83 kg).No significant (P>0.05) difference was observed however in the body weight of RS goats. Male YS with Hb AB had longer (P 0.05) scrotum (26.00 kg) and wider scrotal circumference (33.00 kg) compared to those with Hb AA (18.83kg;25.67kg,respectively). No significant (P>0.05) difference was however observed in there productive parameters of RS goats. It was concluded that polymorphism exist at the Hb locus in the YS and RS goats sampled in Beji and this had an influence on body weight and the reproductive parameters evaluated particularly in the sheep. More heterozygotes were also observed in the population studied there by leading to alow rate of in breeding coefficient in the animals.