Phenotypic characterization of draft donkeys within the Sudano-Sahelian zone of Cameroon

Abstract

Data on age, sex, coat color, liveweight (LW), heart girth (HG), trunk length (TL) and height-at-withers (HW) for 743 donkeys within the Sudano-Sahelian region of Cameroon were recorded. The ages of the donkeys ranged from 0 to 13 years. The effect of age on liveweight, height-at-withers, heart girth and trunk length was highly significant (p < 0.001). The effect of coat color on liveweight and height-at-withers was not significant (p > 0.05). Male donkeys were generally heavier than female donkeys from 0 to 3 years of age. Thereafter, female donkeys became heavier than males (p < 0.002). The average liveweights of adult (6-13 years old) female and male donkeys (132.5 ± 2.3 and 123.2 ± 2.1 kg, respectively) may not have had any significant practical implications on the working capacity of the sexes, given that non visible pregnant female donkeys might have been included in the study. As a result, regression equations established for the estimation of liveweight were not gender discriminative. Consequently, the best prediction equations for donkeys' liveweights within the Sudano-Sahelian region were:

- LW = HG2.826/4434.7 (adjusted R2 = 0.84) for one best fit variable with LW in kilograms and HG in centimeters. When trunk length, or height-at-withers, was considered for one best fit variable in the equation, the adjusted R2 values were 0.78 and 0.66, respectively;

- LW = HG1.947.TL-0.845/3834.8 (adjusted R2 = 0.86) for two best fit variables with TL in centimeters. The inclusion of HW as a third variable in the equation did not modify R2 significantly.