Feather pecking is a big welfare and economic problem in the poultry industry. The Animal Breeding and Genomics Centre showed that current breeding strategies make it possible to reduce pecking in a bird flock. Until now, beak trimming is used as a preventive measure against feather pecking. However, beak trimming is no longer accepted by society, because it is believed to cause lifelong stress as animals are deprived in expressing their natural instinct to peck. Beak trimming will therefore be banned in The Netherlands in the near future. With no alternative measures an increase in mortality is expected. Current research from Wageningen University & Research focuses on development of strategies to reduce feather pecking in bird flocks.
Previous research showed that when improving survival of a bird flock, it is important to include information on both the recipient of feather pecking behaviour and the donors of pecking behaviour in the breeding program. Around 33-76% of the heritable variation for survival is explained by the donors, and the rest by the recipient. These results show that both pecking and being pecked is heritable, which is promising, because the breeding industry can use this information to select against mortality due to feather pecking. At present, breeding strategies move to selection based on DNA information to accelerate genetic improvement.
Breeding companies usually house their chickens in sire-family groups. This design is used to test the genetic potential of the sires for egg production. No distinction between the "recipient-effect" and the "donor-effect" on feather pecking can be made with this design using pedigree information. Nevertheless, the combined effect of the recipient and donors can be captured in the total genetic effect due to the sire. Genetic relationships measured with pedigree information deviate from the actual genetic relationships. The actual genetic relationship can be measured with DNA information. The use of DNA-information, therefore, potentially accelerates genetic improvement of death due to feather pecking. Also, breeding companies usually do not know the mother of the chickens. With DNA information it is possible to identify the mother. For those reasons, DNA can be used to estimate the "recipient-effect" and "donor-effect" separately.
Benefit of DNA information
In a recent publication in the Journal of Animal Breeding and Genetics, researchers of Wageningen University and Research evaluated the potential benefit of DNA information in breeding to reduce feather pecking, where both the "recipient-effect" and "donor-effect" are important. For this study, data on four different laying hen crosses were used. The data were collected by the breeding division of Hendrix Genetics B.V. In this research, it was investigated whether the "recipient-effect" and the "donor-effect" could be estimated separately using DNA-information. Reconstruction of the dam pedigree appeared to be insufficient to pull apart the "recipient-effect" and "donor-effect". Furthermore, DNA information did not improve the estimated breeding values. Nevertheless, the estimated heritable variation ranged from 3% to 25% for survival time in the four chicken crosses. This confirms previous findings that breeding against feather pecking is promising.