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1. In commercial free-range systems for laying hens, popholes to the outdoor range are often installed on one side of the house only. In multi-tier systems, it is possible that some individuals fail to access the range due to internal barriers to movement. 2. Five commercial multi-tier flocks from different units were studied. For each flock, two different colour markers were used to distinguish 200 birds roosting near the popholes (NP-Roost) and 200 birds roosting far from the popholes (FP-Roost) at night. The following day, counts of marked birds on the range and inside the house were performed. 3. Significantly more NP-Roost birds were observed in all areas of the outdoor range than FP-Roost birds the next day. Distance of FP area from the popholes was very strongly positively correlated with effect size in the adjacent range area. 4. Additionally, in the indoor area far from the popholes (FP) more FP-Roost birds were observed the next day than NP-Roost birds. In the indoor area near to the popholes (NP) more NP-Roost birds were observed the next day than FP-Roost birds. 5. These results suggest that roosting location is associated with differential range use when popholes are only available on one side of the shed as birds that roosted far from the popholes used the range less. [ABSTRACT FROM AUTHOR]

1. A study was conducted to investigate the effect of environment on ranging in 33 flocks reared with (16) or without (17) range access. Ranging was observed at 8, 16 and 35 weeks. Information on house layout, weather conditions and range characteristics was used to create models predicting the percentage of the flock out on the range and the percentage of ranging birds observed away from the house. 2. Three flocks had range access at 8 weeks. The percentage of birds ranging averaged 28%, with 22% of these ranging away from the house. For the 13 flocks with range access at 16 weeks, the percentage of pullets on the range was 12%, with 29% of these ranging away from the house. At 35 weeks, all flocks had range access and the average percentage of birds out on the range was 13%, with 42% of these ranging away from the house. 3. The percentage of birds seen using the range was higher with reduced flock size and stocking density, increased pop hole availability (cm/bird) and light intensity inside the house. More birds ranged on cooler days and on farms located in areas with fewer days of rain per year and lower average rainfall. The percentage of birds ranging varied with season and was lowest in May. More birds ranged away from the house when cover and more artificial structures were present on the range. The proportion of ranging birds located away from the house increased with lower outdoor humidity levels, higher air pressure, and on warmer days. Lastly, birds ranged away from the house more as they got older. [ABSTRACT FROM AUTHOR]

1. Management practices, stocking rate and flock size may affect laying hen welfare but there have been few replicated studies in commercial non-cage systems that investigate this. This study used a broad range of physical and physiological indicators to assess the welfare of hens in 36 commercial flocks. 2. Six laying period treatments were examined with each treatment replicated 6 times. It was not possible to randomly allocate treatments to houses, so treatment and house were largely confounded. 3. Three stocking rates were compared: 7 birds/m 2   ( n   =  2450), 9 birds/m 2   ( n   =  3150) and 12 birds/m 2 in either small ( n   =  2450) or large ( n   =  4200) flocks. In addition, at 12 birds/m 2 , in both small and large flocks, birds were subjected to either standard (SM) or modified (MM) management. MM flocks had nipple drinkers and no nest-box lights. 4. Bone strength, fracture incidence, heterophil:lympocyte (H:L) ratio, live weight, organ weights, serum creatine, serum osmolality, muscle pH and faecal corticosterone were measured on samples of birds at the end of the rearing period and at the end of lay. During the laying period, mortality, production and integument condition were recorded at regular intervals. 5 Birds housed at 9 birds/m 2 had higher mortality than birds housed at 12 birds/m 2 by the end of lay, but not higher than birds housed at 7 birds/m 2 . Birds housed at 7 and 9 birds/m 2 had lower percent liver weight, and worse plumage condition than most of the 12 bird/m 2 treatments. Modified management tended to improve plumage condition. There were no clear effects of flock size on the welfare indicators recorded. 6. At the end of the rearing period fracture incidence was almost negligible and H:L ratio was within a normal range. 7. By the end of lay fracture incidence was 60% and H:L ratio was high, with no treatment effect for either measure. This, together with information on faecal corticosterone, feather loss and mortality, suggests that the welfare of birds in all treatments was relatively poor by the end of lay. [ABSTRACT FROM AUTHOR]

The evolutionary link between feelings of pleasure and aversion (affect) behaviour means that measurement of the behaviour of animals can give a unique insight into their own perception of the welfare value of potential enrichment techniques. Consumer demand theory allows ethologists to measure objectively the strength of preference for resources. The current study assessed the extent to which different methods of applying demand theory to laboratory mice would affect the order of prioritisation of four resources. Overall the two methods used showed some agreement, particularly in the prioritisation of food as the most important resource. However in other respects the methods led to different results, for example in the effect of increasing cost on the number of visits to resources. The importance of using animals' behaviour when making practical welfare assessments is emphasised. [ABSTRACT FROM AUTHOR]