Authors: M. N. Bemji, A. A. Ogunjimi, A. J. Ode, S. R. Okediji , A. T. Akinwunmi , T. O. Sanyaolu , B. S. Salawudeen , B. A. Kelani , A. O. Ogunsola , M. O. Agunbiade , A. S. Adenaike
American Journal of Experimental Agriculture 2(4): 5 87-596, 2012
Abstract
The West African Dwarf (WAD) sheep reared extensively by small holder farmers in South Western Nigeria has not been selected based on preference for coat colour, which varies considerably but without adequate information on the current distribution. The prevalence of different coat colour phenotypes was therefore investigated based on a total randomly sampled size of 9, 195 sheep (5,978 females and 3,217 males) from February to October, 2011. A total of 17 different colour patterns including 3 solid colours (white, black and brown) were identified in the breed. Phenotypes mainly influenced by phaeomelanin wt pigment, considered to be governed by a dominant allele (A) include: predominantly white with black marking, solid white, white and black in approximately equal proportions, spotted white, white and brown in approximately equal proportions, buckskin, tan, badgerface and grey. The remaining phenotypes (black with white marking, brown, black, spotted black, spotted brown, black and brown, brown with white marking and Swiss marking) reflected the presence of eumelanin pigment governed by Aa recessive allele. Based on the two pigment types, 71.58% and 28.42% of sheep had coat colour predominated by 2 phaeomelanin and eumelanin pigments, respectively. Result of chi square (X ) analysis showed that the difference between observed and expected frequencies was significant (P=.05) implying that there was a deviation from the expected 3:1 Mendelian ratio. Conscious selection could be embarked upon to investigate and conserve phenotypes that are more genetically superior in terms of productivity and adaptation.