A study of the abrasion losses of claws obtained from different breeds did not confirm the hypothesis that dark pigmented claws are more resistant than light pigmented claws. It could be shown that factors such as the moisture and the microstructure of the horny walls of the claw influence the hardness of claws more than the pigmentation of the horny walls of the claws. A comparison between the Simmentaler from Germany and the Afrikaner proved that both breeds in the environment to which they have become adapted showed low values for both the growth and the abrasion of the claw horn, while animals exported to South and South West Africa exhibited higher values. Evaluation of the growth and abrasion of the claw horn as well as the histological investigations indicated that adaptation of the Simmentaler in South and South West Africa is a continuous process, but is unlikely that the level of adaptation of the Afrikaner will be equalled.