Produksiepotensiaal van verskillende eerstekruising Afrikanerbeeste

English: In the development of crossbreeding systems in beef production under South African conditions, more information on the combination ability of various types of exotic beef breeds with the indigenous Africander is of primary importance. For this reason four breeds of bulls namely Brahman, Charolais, Hereford and Simmentaler were used on purebred Africander cows in this study. These breeds represented a Zebu type, large frame lean meat type, small frame fat meat type and a large frame dual purpose type of cattle respectively. Simultaneously purebred Africanders were produced as controls. The progeny of the five bull breeds (838 in total) were evaluated in respect of duration of gestation, birth and weaning mass. Postweaning growth and development of steers as slaughter animals were studied under two production systems while the female progeny were evaluated as breeding animals. Special attention was given to the occurrence of interactiombetween sire breed and production system as well as sire breed and production function. It is apparent that the choice of a breed/type of bull for the production of Africander F1-calves is of utmost importance due to the effect thereof on birth mass. and dystocia. As a result of the extreme size of the Charolais-Africander calves at birth and the extent of dystocia, the production of this cross seemed not to be of any merit. Furthermore, although this combination of breeds performed very well in a semi-intensive production system, it was found that the female progeny lack in mothering ability and cannot be recommended as replacements in herds. The crosses of Brahman, Hereford and Simmentaler bulls, however, proved to be of excellent potential for exploitation under specific conditions. The Brahman progeny has a dual purpose production potential in an extensive production situation as a store animal as well as a replacement heifer. Likewise the Simmentaler cross has a multi-purpose production function in terms of replacement heifer and slaughter animal. For the latter purpose it became apparent that this cross is equally efficient as a fodder animal or store, keeping in mind that it only becomes marketable at an advanced mass especially under extensive grazing conditions. Hereford crosses proved to be extremely suitable as Slaughter animals, regardless of the production system, although it performed especially well under intensive management.