Discriminant analysis of morphometric differentiation in the West African Dwarf and Red Sokoto goats

Abstract

This study evaluated the usefulness of morphological characteristics to distinguish two important indigenous goat breeds in Nigeria. Fifteen morphometric traits were measured on West African Dwarf – WAD (n = 160) and Red Sokoto – RS (n = 142) goats that ranged in age of up to 19 months and were reared extensively in villages in southern and northern Nigeria. Univariate analysis revealed that the body measures of RS goats were significantly higher than those of WAD goats. Canonical discriminant analysis gave better resolution, as only seven external morphological characteristics of strong discriminating power were extracted. The most discriminant variable between the two goat populations was rump height, followed in order by body length, horn length, face length, chest girth, neck circumference and head width. The discriminant function obtained correctly classified 100% of individuals from the sample of known goat populations. The classification accuracy of the function was cross-validated using the split-sample method, and indicated a 99.7% success rate (99.4% of WAD goats and 100% of RS goats were correctly assigned to their source genetic group). This study indicates that a discriminant tool may be used successfully in the field to separate WAD and RS goats. The present results could be complemented by molecular characterization using DNA markers for better management and conservation strategies of genetic resources for indigenous goats.