Institute Of Selection Animale Isa | Date: 2007-08-07
Leenstra F.,Livestock Research |
Maurer V.,Research Institute of Organic Agriculture FiBL |
Bestman M.,Louis Bolk Institute |
van Sambeek F.,Institute Of Selection Animale Isa |
And 4 more authors.
British Poultry Science | Year: 2012
1. A total of 257 farmers with free ranging laying hens (organic and conventional) in Switzerland, France and The Netherlands with 273 flocks were interviewed to determine the relationships between the genotype of the hens, management conditions and performance.2. Almost 20 different genotypes (brands) were present on the farms. In France, all birds were brown feathered hens laying brown eggs. In Switzerland and The Netherlands, there were brown, white (white feathered hens laying white eggs) and silver (white feathered hens laying brown eggs) hens. In Switzerland, mixed flocks were also present.3. The overall effect of system (organic vs. conventional free range) on egg production and mortality was significant, with higher mortality and lower egg production among organic hens. In pair wise comparisons within country, the difference was highly significant in The Netherlands, and showed a non-significant tendency in the same direction in Switzerland and France.4. White hens tended to perform better than brown hens. Silver hens appeared to have a higher mortality and lower production per hen housed at 60 weeks of age.5. There were no significant relationships between production, mortality, feather condition and use of outside run or with flock size.6. There was more variation in mortality and egg production among farms with a small flock size than among farms with a large flock size. © 2012 Copyright Taylor and Francis Group, LLC.
LEENSTRA F.,Wageningen UR Livestock Research |
TEN NAPEL J.,Wageningen UR Livestock Research |
VISSCHER J.,Institute Of Selection Animale Isa |
VAN SAMBEEK F.,Institute Of Selection Animale Isa
World's Poultry Science Journal | Year: 2016
The housing and management of laying hens and their productivity has gone through enormous developments in the last century. Housing has changed from free-range systems, via battery cages to a variety of loose housing and different types of battery cages, and back to outdoor access systems. Although battery cages are still the main system used worldwide, the number of hens housed in aviaries and free-range systems has increased in Europe, Australasia and some parts of the USA, but aviaries and free-range systems are still considered a niche sector compared to caged housing. The following paper reviews how breeding and selection have responded to changes in housing and management and whether different types of housing require different breeding programmes and, more specifically, whether a dedicated breeding programme should be developed for aviary and free-range systems. From the available literature it was concluded that broadening the selection goal in existing lines is the best option for breeding programmes to provide genotypes that are suitable for a range of housing systems. Copyright © World's Poultry Science Association2016
Institute Of Selection Animale Isa | Date: 2011-04-05