Spatial variation in goat populations from Benin as revealed by multivariate analysis of morphological traits

Thirteen morphological traits were measured on a total of randomly selected 1672 female mature goats from four vegetation zones ranging from South towards North Benin. Four populations were characterized as distinct and may be referred to as ecotypes. The cluster analysis showed that the two southerly populations were closest to each other. Populations from northernmost vegetation zones always had larger features and less additional teats than those from southernmost zones. They also tended to have wattles and dropping ears. In the canonical discriminant analysis, the first two canonical variates were significant and accounted for 92% of the variability among vegetation zones. Measurements that were best able to separate the populations, as judged from the canonical variate analysis, were: height at withers, neck length, rump height, tail length and the ratio ear length/thoracic depth. Discriminant function models correctly allocated more than 70% of the individual goats to their a priori vegetation zones. These results provide supporting evidence for spatial variation in population of goats in Benin. They also underscore a need for further on-farm performance experiments that will lead to the characterization of these populations on a sound ecological basis and allow formulation of sustainable breeding and management strategies.