Proximo-distal gain of asymmetry in lamb metacarpals

The ability of an organism to produce an ideal phenotype, despite the disturbances encountered during its development, is the causal mechanism of developmental stability. This ability is used to evaluate a variety of stress types and the genotypic ability to correct them. Geometric morphometric techniques were used to study the matched symmetry in form (size and shape) of right and left metacarpal bones in a sample of 48 lambs collected from abattoir facilities, on which 10 landmarks were located. Left and right metacarpal form showed statistically significant directional asymmetry, i.e. left and right body sides differed consistently from each other. The main shape differences were on the condylar reliefs of the distal part of the bone. These findings provide a reliable reference data set for future investigation on whether the morphology of the metacarpals is influenced by age and other factors such as the productive use of the animal (e.g. for meat, milk or wool).