Principal component analysis (PCA) in the morphostructure of male Kabylie donkeys (Equus asinus), Algeria

Abstract

Principal component analysis (PCA) is important to describe the total phenotypic variance in livestock. Hence, the selection of livestock can be performed with the main component (PC1) of some phenotypic traits. This research was carried out to obtain the principal component (PC) in the morphostucture of male donkeys (Equus Asinus) at the Kabylie area of Algeria. Two different locations of Bejaia and Tizi-Ouzou province were chosen randomly. A total of 121 male donkeys (jackass) with an average age of 10.75±4.58 years were used in this study. Data of animals’ morphostructure consisted of 17 body measurements and 6 body indices. The PCA analysis in body measurements and body indexes were showed 5PC’s and 3PC’s, respectively that explain total variance in animals’ morphostructure. Besides, 5PC’s of body measurements and 3PC’s of body indexes had a total variance proportion of about 66.79% and 81.12%, respectively. According to Bartlett’s test, both PCA’s in this study were accurate (with significance of less than 0.05). According to Kaiser-Meyer-Olkin (KMO), the PCA of body indices was not accurate (KMO = 0.35). It was concluded that body measurements of chest depth, chest width, front-leg length and back length as the PC1 explain 32.16% of the total variance in animals’ morphostructure. In conclusion, the PCA of body measurements in this study is accurate with a high KMO value and significance of Bartlett’s test. The results of this study can be used as the basic information to develop a selection program for Algerian donkeys in the future.