Equation for Predicting the Load-Pulling Capacity of Traction Equids

This study proposed a loading capacity equation for urban cart-pulling equids. The research was conducted in two stages: the first developed the equation, and the second applied it by analyzing the zoometric structure of animals already employed in this activity. The equation was formulated by applying Newton's laws of motion, starting from an ideal model that did not consider dissipative forces, and the variables, such as friction force, animal morphological indices, and maximum supported load, were subsequently added. Next, the equation was applied using body weight data for 228 pulling equids, including 49 horses (18 males and 31 females) and 179 mules (13 males and 166 females), estimating the mean body weight for each sex in both species. This evaluation also considered variations in terrain friction coefficients on different terrains. The value of 0.0015 was used as the friction coefficient for spherical bearings in the cart axles. The results were subjected to analysis of variance and means testing (Duncan's test at 5% probability) to establish the relationship between the resulting means for male and female horses and mules separately. The maximum load value obtained in these cases was approximately twice the animals' mean live weight. The findings of this study indicate that equations can be applicable and should be validated by additional experiments using alive equids.