Comparison of the welfare of layer hens in 4 housing systems in the UK

Abstract

1. The welfare of hens in 26 flocks (6 conventional cage, 6 furnished cage, 7 barn, 7 free-range) was assessed throughout the laying period using a combination of data on physical health, physiology and injurious pecking, collected by researchers on farm and during post-mortem analysis, and information submitted by producers. 2. There was an effect of housing system on 5 of the indicators recorded by researchers: gentle feather pecks given, feather damage score, proportion of hens with feather damage, proportion of the flock using perches, and faecal corticosterone. 3. Post-mortem analysis revealed several differences between housing systems in skin damage, plumage damage to the vent and abdomen, keel protrusion, bodyweight, and the proportion of hens that were vent pecked and that had old and recent keel fractures. 4. There was an effect of housing system on 5 indicators recorded by producers: proportion of egg shells with calcification spots, proportion of egg shells with blood stains, weight of hens found dead, temporal change in the proportion of egg shells with stains, and temporal change in proportion of hens found dead. 5. Each housing system had positive and negative aspects but overall, hens in barn systems had the highest prevalence of poor plumage condition, old fractures, emaciation, abnormal egg calcification, and the highest corticosterone. Hens in conventional cages sustained more fractures at depopulation than birds in other systems. Vent pecking was most prevalent in free-range flocks. The lowest prevalence of problems occurred in hens in furnished cages. 6. Although housing system had an influence on the hens' physical condition and physiological state, the high prevalence of emaciation, loss of plumage, fractures and evidence of stress is of concern across all housing systems, and suggests that the welfare of modern genotypes is poor.

Hen egg carotenoids (lutein and zeaxanthin) and nutritional impacts on human health: a review

“…Beyond doubt, the chemical and nutrient composition of hen's egg is well documented (Kovacs- Nolan, Phillips, & Mine, 2005;Li-Chan & Kim, 2008;Seuss-Baum, 2007). Researchers analyzed quality parameters of poultry from organic and conventional farms (Sherwin, Richards, & Nicol, 2010). Different rearing systems produce eggs with distinct yolk carotenoid composition because of the differences in feed utilization (Schlatterer & Breithaupt, 2006).…”

“…During the past century, improved feeding and lighting systems have led to year round egg production which was supported by advanced confinement and management systems. Globally, a range of relevant management systems is applied (Sherwin et al, 2010). The specific type is determined largely by climatic and economic constraints.…”

“…Hens producing organic eggs must have access to the outdoors and cannot be housed in cages (Sherwin et al, 2010). The hen's feed must be free of antibiotics and synthetic chemicals and must include grains from only crops certified as 'organic.'…”

“…Houses must incorporate ventilation systems to provide fresh air and to maintain temperature and humidity produced by the chickens. Layers generate a great deal of body heat (Castellini, Mugnai, & Dal Bosco, 2002;Combes et al, 2003;Sherwin et al, 2010).…”

“…Land to produce such crops must have been free of 'genetically modified' crops and synthetic fertilizers for three or more years. Antibiotic use is permitted only for disease outbreaks (Cherian, Holsonbake, & Goeger, 2002;Sherwin et al, 2010).…”