Abstract
Enrichments during pullet rearing may improve adaptation and welfare of hens as they move from indoor rearing to a free-range system. Individual variation in outdoor ranging may also affect welfare. This study assessed the effects of rearing enrichments and an imposed environmental stressor on hen welfare and egg quality along with the association of welfare with ranging. Hy-Line Brown® chicks (n = 1,386) were reared indoors until 16 weeks with 3 enrichment treatments including a “control” group with standard floor litter, a “novelty” group that received novel objects that were changed weekly, and a “structural” group with H-shaped perching structures. Pullets were then moved to a free-range system with three replicates of each rearing treatment. Daily ranging was individually tracked from 25 to 64 weeks via radiofrequency identification technology. Individual hen welfare assessments were performed at 25, 33, 43, 56, and 64 weeks and correlated with ranging time prior to these dates. At 44 weeks, the range area was reduced by 80% for 11 days to induce stress. Changes in ranging behavior, albumen corticosterone concentrations and egg quality were evaluated. GLMMs showed significant interactions between hen age and rearing treatment for live weight, number of comb wounds, plumage coverage, and toenail length (all P ≤ 0.003), with the enriched hens showing more consistent live weight at the later ages, fewer comb wounds at 33 weeks, and better plumage coverage at the later ages, whereas the structural hens had shorter toenails as age increased. Plumage coverage showed a positive relationship with range use across most age points (P < 0.0001). Hens reduced ranging time following the imposed stressor but increased their number of visits with the lowest increase by the structural hens (P = 0.03). Significant interactions between rearing treatment and stressor for albumen corticosterone concentrations showed the structural hens decreased concentrations immediately post-stress, but the control and novelty groups increased (P < 0.006). The stressor increased or decreased values of most egg quality parameters across all rearing groups (all P ≤ 0.02). Overall, provision of rearing enrichments and greater range use may have positive impacts on hen welfare.
Highlights
Animal welfare concerns are prevalent within the consumer community with apprehensions regarding the housing and management of livestock and desires for improvements that result in greater well-being for production animals [1,2,3,4]
There was a significant interaction between hen age and rearing treatments for the live weight of free-range hens [F(8, 5475) = 5.46, P < 0.003] where the control hens showed a smaller increase in body weight at 56 weeks of age and a greater reduction at 64 weeks of age compared to the structural and novelty hens (Figure 1)
There was a significant interaction between hen age and rearing treatments for plumage coverage [F(8, 5476) = 86.43, P < 0.0001], where both the novelty and structural hens had better plumage coverage than the control hens at the later ages (Figure 3)
Summary
Animal welfare concerns are prevalent within the consumer community with apprehensions regarding the housing and management of livestock and desires for improvements that result in greater well-being for production animals [1,2,3,4]. Outdoor access and time spent ranging, a higher proportion of hens ranging, or distance of ranging by free-range hens may result in some welfare benefits to the birds. This may include improved plumage coverage [9,10,11], reduced incidences of severe feather pecking [12], reduced footpad lesions [10] and reduced toenail length [13, 14]. In a sample of hens from the larger flock used in the current study, high outdoor access resulted in improved plumage coverage, a reduced number of pecking comb wounds, and reduced toenail length toward the end of the production cycle [16]. Research examining the longitudinal relationship between individual range use patterns and welfare parameters will provide further insight
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
