Environmental Complexity and Reduced Stocking Density Promote Positive Behavioral Outcomes in Broiler Chickens

Abstract

The objective was to evaluate the impacts of a complex environment and stocking density on Ross 708 broiler chicken behaviors. Eight pens contained either high complexity (HC) or low complexity (LC) environments, and high (HD) or low (LD) density. Through focal-animal sampling, the frequency and duration of behaviors were recorded continuously for 5 min at two timepoints for one day in weeks 2, 4, and 7. Birds were active for 30% of the observed time, with birds showing more activity in HC compared with LC. Birds in HC pens spent more time preening and foraging than birds in LC pens, which was interpreted as a positive outcome. Dustbathing and play were not impacted by complexity, possibly due to the observation method. Birds were more frequently active at HD compared with LD, but did not spend more time being active, suggesting disturbances. Birds foraged, drank, and ate less frequently in HD compared with LD, presumably because birds had more difficulty accessing resources. Activity and active behaviors reduced as birds aged, while preening frequency increased, possibly due to frustration, but this was not confirmed. Perching was unaffected by age, showing a persistent motivation to perform the behavior. Our results indicate that a complex environment provides positive stimulation for foraging, locomotion, preening, and overall activity. Despite reduced activity, many benefits of the tested environmental complexity and low density persisted as birds aged.

Effect of dietary aspirin eugenol ester on the growth performance, antioxidant capacity, intestinal inflammation, and cecal microbiota of broilers under high stocking density

“…While the adoption of a high density feeding approach may offer potential benefits in terms of cost reduction and income generation, its implementation can lead to adverse changes in the behavior, physiology, metabolism, and health of broiler chickens, culminating in the manifestation of stress responses ( Jones et al ., 2005 ; Najafi et al ., 2015 ; Evans et al ., 2023 ). When the physiological stress response mechanism is activated in broiler chickens under stress, it results in changes in both the immune system and the blood biochemical parameters.…”

“…In pursuit of economic benefits, however, there is a tendency to opt for higher stocking densities ( HD ). Although this strategy can reduce breeding expenses and increase profits, it can also result in changes to the behavior, physiology, and metabolism of broilers, ultimately triggering stress responses ( Jones et al ., 2005 ; Najafi et al ., 2015 ; Evans et al ., 2023 ). The stressors linked to HD stress exhibit a significantly intricate nature in comparison to other stress reactions.…”

Laying Hens: Why Smothering and Not Surviving?—A Literature Review

“…For a long time, this behavior was described as a normal congregation, associated with high stocking densities (birds/m 2 ), and erroneously correlated with overcrowded housing of broiler chickens (average of 18 birds/m 2 or 35 kg/m 2 ) [ 52 ]. However, for laying hens, it only gained more visibility with the increasing demand for eggs in cage-free systems, when this behavior became a challenge to animal welfare [ 53 ].…”

Nrf2 Signaling Pathway as a Key to Treatment for Diabetic Dyslipidemia and Atherosclerosis

“…Chronic accumulation of lipid and fiber plaques on arterial walls restricts blood flow and results in critical hypoxia in tissues [ 7 ]. Inflammation is initiated by the accumulation and modification of lipoproteins, such as low-density lipoprotein (LDL) [ 8 ]. The progression of the inflammatory lesion is then promoted by leukocyte recruitment and expression of pro-inflammatory cytokines.…”