Dual-purpose production of eggs and meat-part 2: hens of crosses between layer and meat breeds show moderate laying performance but choose feed with less protein than a layer hybrid, indicating the potential to reduce protein in diets

The use of modern chicken genotypes with high egg or meat performance results in the ethically unacceptable practice of culling day-old male layer chicks because of their inefficient fattening performance. Dual-purpose genotypes with a balanced performance profile for eggs and meat are one option to avoid this practice. In this study, the performance of four crosses of a layer breed (White Rock or New Hampshire) and the meat breed Bresse Gauloise, purebred Bresse Gauloise and the layer hybrid Lohmann Sandy was compared under organic husbandry conditions. Part 2 focuses on the laying performance of the hens until the age of 72 weeks and their feed choices when offered energy-rich and protein-rich feed mixtures. Feed consumption was generally high (133-143 g day(-1)), but the crosses consumed less protein feed than Lohmann Sandy, indicating a potential to reduce the proportion of high-protein components. Bresse Gauloise x White Rock showed severe plumage loss due to feather pecking, which was most likely caused by their low consumption of protein feed. Apparently, free-choice feeding did not agree with this genotype. Average laying performance of the crosses was 68-73% total eggs per average hen, which can be considered moderate. Average egg weights and egg size distribution were comparable with Lohmann Sandy, while slaughter performance of the senior hens was comparable with purebred Bresse Gauloise. Based on these findings, egg production with dual-purpose laying hens can be an ethically desirable alternative to high-performance genotypes, but will require further research on optimal feeding strategies and animal behaviour. Trial registered on July 7, 2017 (reference number V 241-26532/2017)