Cross Breeding Cockerels (Black Rhineländers and Leghorn and Black and Speckled Rhineländer) were compared with pure bred Leghorn Cockerels. Deutsche Landwirtschaftliche Geflügelzeitung, 1934, Nr. 30.

The question of utility cross breds has been appraised in wide circles, and especially by beginners, as a matter of great importance in poultry breeding. The Institute for Veterinary Research of the Prussian Experiment and Research Institute for Breeding has published a report giving the results of an experiment where in a review is given of the fattening qualities of cross bred birds. The results of this research work proved that pure Leghorns are superior to Leghorn-Rhineland cross-breds and also to Rhineländer crossbreds, with regard to mortality, increase of weight and cost of feeding. On the basis of the results achieved by him and of those which have been published previously, and in spite of contrary opinions expressed by practising poultry breeders, the writer rejects the idea that the Leghorn has been surpassed in its constitutionally established power of resistance either by other breeds, which are not so extensively kept on big farms for fattening, or by cross-bred Leghorns. The qualification of the F1 crossbred as regards laying capacity is quite a different question. The experiment was based on quite other grounds but in view of what has already been published and on the basis of what the writer has experienced with other F1 cross breds, it can now be said that the F1 cross breds do not in every case lay better than the older breeds but that very often the laying capacity of the cross breds holds a medium place between the older breeds.