Haemoglobin genetic types and its association with qualitative traits in West African Dwarf sheep

Abstract

This study was carried out to investigate the haemoglobin genetic types and their association with qualitative traits in West African Dwarf (WAD) sheep. The Modified Stratified Sampling Technique (MSST) was used to select the sampling sites within the selected state and animal samples within the sampling sites. A total of 280 adult sheep comprising 140 rams and 140 ewes aged 4 years were used for the study. Data were collected on Mendelian traits such as the horn status, wattle status and hair length on sex basis. Blood samples were collected from the animals for haemoglobin genetic types’ determination. The results showed that in ewes, the f(HbAA), f(HbAB) and f(HbBB) were 0.36, 0.28 and 0.36, respectively and the f(HbA) and f(HbB) was 0.50 in both alleles.  In rams, the f(HbAA), f(HbAB) and f(HbBB) were 0.68, 0.14 and 0.18, respectively and the f(HbA) and f(HbB) were 0.75 and 0.25, respectively. In the pooled data, f(HbAA), f(HbAB) and f(HbBB) were 0.68, 0.14 and 0.18, respectively and the f(HbA) and f(HbB) were 0.625 and 0.375, respectively.  The estimated heterozygosity was 0.47 and the estimated local inbreeding coefficient was 0.054. The hair length indicated sexual dimorphism with 12.79 to 12.98 cm in rams and 4.79 to 4.98 cm in ewes but was not dependent on the heamoglobin genetic types. The result shows that the status of wattles is not influenced by sex. The WAD sheep used had three haemoglobin genotypes under the control of two alleles at the haemoglobin locus. Key words: Ewe, haemoglobin genetic type, inbreeding coefficient, Mendelian traits, ram.