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Title: The use of range, behaviour, nearest neighbour distance and feather condition of commercial free-range laying hens
Author: Chielo, Leonard Ikenna
ISNI:       0000 0004 6422 1013
Awarding Body: University of Lincoln
Current Institution: University of Lincoln
Date of Award: 2017
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This thesis is based on the evidence of the use of range by laying hens from two separate studies that were carried out on commercial flocks. The first study involved a direct observation of 6 flocks of laying hens whereas the second study was carried out on a single flock of laying hens using a still digital camera. Mapping of the outdoor range into three zones, namely; apron (0-10metres), enriched (10-50metres) and range (beyond 50metres), was carried out in both studies determine whether it influenced the distribution, behaviour, nearest neighbour distance (NND) and feather condition of the hens. Based on the estimates of the total number of hens recorded outdoors, it was found that 14.5% of the hens used the range in the first study, with 6.0% of the hens seen in the apron, 4.8% in the enriched and the remaining 3.7% in the outer range zone. This ranging pattern was further confirmed by the quadrat head counts, where the hens used the apron most but showed a significant decrease in the use of other outdoor zones as distance increased from the shed (p < 0.001). The results of the two studies showed that range use peaked in the morning and decreased significantly in the afternoon (p < 0.001). Range use was found to increase significantly with age (p < 0.001) in the first study, although there was a significant decrease in the number of hens outside the shed as the flocks got larger (p < 0.001). The age effect reported in the six-flock study was complemented by the significant positive effect of the week of outdoor access on the ability of the hens to use the range (p < 0.001) in the single flock study. Range use increased as outdoor temperature rose in the six-flock study whereas increased outdoor temperature resulted in a decline in range use in the single flock study. NND of the hens was ii measured in the six-flock study and was found to decrease significantly towards the shed (p < 0.001) and as the hens aged (p < 0.001). There was evidence that the use of distant and less crowded outdoor locations by the hens in the first study was associated with improved feather conditions. The evidence presented in the two studies presented in this thesis showed that the hens were unevenly distributed in the range, with reduced hen density (hen/m2) towards the outer range and that an improvement in the use of distant parts of the range may have beneficial effects on the hens.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: D300 Animal Science ; D328 Animal Welfare