Phenotypic characterization of donkeys in Benishangul Gumuz national regional state

Abstract

Fifteen morphometric measurements and eighteen qualitative traits were recorded on 323 randomly sampled adult donkeys (123 jacks and 200 jennets) to meet an objective of characterizing a heterogeneous donkey population of three phenotypic types (Sinnar, the locals and their crosses) found in Benishangul Gumuz region of Ethiopia. The General Linear Model and non-parametric test (chi-square) procedures of SAS software were used for the analysis of the morphometric data and qualitative traits, respectively. Means were separated using the Tukey-Kramer test. The studied morphometric measurements were significantly affected by the phenotypic type and partially affected by sex and sample location /district. Sinnar donkeys were significantly bigger and heavier than the local and the crosses. However, for some of the morphometric measurements no significance difference was observed between Sinnar and crosses implying the presence of heterosis. Heart girth measurements for Sinnar, local and crosses were 110.61±0.436, 106.18±0.448 and 108.87±1.251, respectively. Body weight estimates of 127.26±1.277, 113.40±1.312 and 121.13± 3.665 kg were obtained for Sinnar, the local and the crosses. There was sexual size dimorphism and depending on the type of morphometric trait either jacks or jennets show significantly (P<0.05) higher values as compared to the opposite sex. Jacks had wider chest (22.61 vs 22.09 cm.), thicker (24.40 vs 23.24 cm.), and longer cannon bone (31.00 vs 31.32 cm) than jennets, while the jennets possess wider hip (33.00 vs 31.69 cm.) and longer body (90.49 vs 88.52 cm.), back (67.37 vs 66.17), ear (24.42 vs 23.90 cm) and heavier estimated weight (122.47 vs 118.71 kg) than the jacks. Limited location effect was recorded showing donkeys from Guba district were comparatively the largest. Majority of the studied donkeys possess white abdominal color, unpigmented hoof and muzzle, short and medium hair size, plain body color pattern with long dorsal stripe without leg stripe, straight face and sloppy rump profile, medium tail length and thickness at the base of the tail. Qualitative differences (P<0.05) were also observed among the class categories. Further molecular level studies could supplement the current study and provide more refined classification of the various genotypes in the studied area. Similarly, characterization of the local donkeys found in other parts of the region and the Abyssinian donkeys in the adjoining areas is required.