- Determination of the area difference between the two main claws on the photographs as basis for the scoring system of claws’ asymmetry. Percentages (%) referring to differences in footing area. A-Score 0 represented by a left hind claw, 4 weeks old; A-Score 1 represented by a left front claw, 4 weeks old; A-Score 2 left hind claw, 4 weeks old; A-Score 3 slaughter pig left front claw (pictures taken by Sarah Seufert)