Effect of Environmental Enrichment on the Behavior and Welfare of Japanese Broilers at a Commercial Farm

Abstract

The effect of hay bales and perches as environmental enrichment material was investigated on the behavior, heterophil/lymphocyte (H/L) ratio, footpad dermatitis (FPD), and productivity of Japanese broilers in a commercial farm. About 21,500 birds were allocated to 4 houses: male versus female×control versus treatment house. We observed maintenance behavior, the utilization of hay bales and perches, and the H/L ratio of birds at 3, 5, and 8 weeks of age. FPD was scored and productivity was calculated at about 60 days after hatching. Compared to birds in the control houses, birds in the treatment houses invested more time in stand-resting and moving behaviors (P＜0.01, for each behavior) and less time feeding, drinking, and sit-resting (P＜0.01, for each behavior). Females used the hay bales and perches more than the males (P＜0.1 and P＜0.01, respectively). The activity and utilization of hay bales and perches decreased with age (P＜0.01, for each behavior, respectively). The H/L ratio of birds in the treatment houses was lower than that in the control houses (P＜0.01). The prevalence of FPD was milder in the treatment houses compared to the control houses for females (P＜0.01), but not for males. In conclusion, hay bales and perches represent effective enrichment materials, allowing broilers to express normal behavior, alleviating stress in the younger and lighter birds of both sexes, and reducing FPD in female birds using the hay bales and perches more than males.

The Productivity and Financial Impacts of Eight Types of Environmental Enrichment for Broiler Chickens

“…FCR was slightly improved, but mortality was also elevated. This result contradicts the findings of Ohara et al [6], who found a positive enrichment effect of straw bales and perches on FPD in female birds, but not males. No separate analysis by sex was undertaken in this study.…”

“…To address these welfare problems some recent studies have examined the possibility of improving leg health by increasing bird activity by means of providing environmental enrichment. Examples of types of environmental enrichment tested include the provision of perches [4][5][6], placing hay or straw bales into housing [7,8], introduction of sand trays, vegetable materials, hanging objects [5], a dust-bathing substrate, and mirrors [8,9]. All of these enrichments involve changing the nature of the rearing environment to increase its complexity.…”

“…They have done this using a range of different health and welfare measures. For example, Ohara et al [6] found that the provision of hay bales and perches increased bird activity levels (more standing and moving) in both male and female broilers and reduced the severity of footpad dermatitis (FPD) in female birds. On the other hand, Bailie et al [7] found no effect of either straw bales or natural light on FPD, while Sans et al [5] found no effect on FPD of providing perches, sand tray, kale, green cabbage and hanging objects.…”

Effects of Outdoor Access and Indoor Stocking Density on Behaviour and Stress in Broilers in the Subhumid Tropics

“…Physical activity increases both the thickness and density of the cortical bone and the diameter of the tibiotarsus diaphysis. The extent depends on the level of activity [32]. This deleterious effect of stocking density and age on locomotion has been observed previously [37,38].…”

“…It was not possible to complete the intended observation in week 6, since some animals exceed 3 kg of body weight and started to show mild signs of leg disorders. Video recording was used to crosscheck the behaviour at 10 min intervals and increase the accuracy of the counts [19,31,32]. The sole observer was blind to all aspects of treatments and intraobserver reliability, expressed as Pearson correlation coefficient, was 0.99 [30].…”