Morphometric characterization of Nigerian indigenous sheep using multifactorial discriminant analysis

Abstract

Adequate knowledge of diversities within and between animal populations will not only help in reducing misidentification in animal husbandry but also aid conservation of many important endangered alleles. A total number of 1195 animals comprising 380 Yankasa sheep, 414 Uda sheep, 224 Balami sheep and 177 West African Dwarf (WAD) sheep were sampled from Osun and Oyo states, South Western Nigeria. Yankasa and WAD were sampled from traditionally managed flock while Balami and Uda sheep were obtained from markets in these states. Seventeen (17) morphometric characters were measured to study their phenotypic variations. The characters measured include rump width (RW), rump length (RL), tail length (TL), wither height (WH), heart girth (HG), paunch girth (PG), rump height (RH), ear length (EL), foreleg length (FLL), rear-leg length (RLL), body length (BL), shoulder width (SW), neck circumference (NC), head length (HeL), head width (HW), horn length (HL) and hock length (HoL). Stepwise multifactorial discriminant analysis was explored to check traits that best differentiate the Nigerian sheep. Length of tail was the most discriminating character among the eight distinguishing traits found. Longest genetic distance was found between WAD and Uda sheep while the closest breeds were Balami and Uda, as indicated by the Euclidian distance. The large Euclidian distance obtained for genetic gap between Uda and WAD sheep gives prospect for improvement if they are crossbred. Since Uda and WAD have been reared successfully in the arid Northern region and trypano-endemic region of Southern humid Nigeria, respectively, crossing WAD with Uda will produce a relatively large, heat tolerant and trypanotolerant hybrid. Key word: Phenotypic variation, Nigerian sheep, discriminant analysis.