The objective of the present experiment was to compare the performance, egg quality and organ morphometrics of commercial layers submitted to alternative forced molting methods using dietary fibers. The experimental period included the phases of molting, rest, and second laying cycle (six periods of 28 days each). In the trial, 320 commercial Isa Brown layers …
The aim of this study was to compare the applicability of the non-feed removal method with the feed withdrawal method by using alfalfa meal and barley in molting. Moreover, the effects of humate (2 g/kg), carnitine (0.1 g/kg) and humate (2 g/kg) + carnitine (0.1 g/kg) supplementation to the diets during postmolt period along with …
This study was conducted to determine the ability of different molt diets to induce molt in 95-wk-old hens. The hens were randomly assigned to 4 treatments of 60 birds each: 1) molted by full feeding with broken rice (BROK), 2) corn (CRN), 3) cassava (CASS), or 4) nonmolted control (CONT) for 14 d. At 15 …
The neuroendocrine system controls animals’ adaptability to their environments by releasing psychotropic compounds such as catecholamines [epinephrine (EP), norepinephrine (NE), and dopamine (DA)], corticosterone (CORT), and serotonin (5-hydroxytryptamine or 5-HT). Changes of these neuroendocrine compounds have been used as biomarkers of animals’ stress responses associated with their well-being. Assuming that pullets, like laying hens, are …
Osteoporosis, a progressive decrease in mineralized structural bone, causes 20 to 35% of all mortalities in caged White Leghorn hens. Previous research has focused on manipulating the egg laying environment to improve skeletal health, with little research on the pullet. The objective of the current study was to determine the effect of perch access on …
The aim of this trial was to determine the influence of aerial perches on welfare and production parameters in free-range laying hens. Five commercial free-range houses, each containing between 7000 and 8000 birds, were used. Each house and range area was split in half to create two treatments. In half of the house the birds …
Provision of perches in cages could improve behaviour and physical conditions of layinghens. This study was conducted to investigate the choice of perch characteristics (shape, width, material and height) by caged hens under different group size, and to understand the choice by the perching behaviours of hens. This study was consisted of four trials: perch …
In a two-year experiment, we investigated the influence of sward plant species composition (sward type), stocking duration and state of sward degradation on the foraging behaviour of chickens. Laying hens (ISA Warren) were pastured on 15 sward types including 14 mono-cultures of grassland plant species (nine grasses and five forb species) and one mixed sward …
Using laying hens, we investigated whether position of a nest box, both within the pen and relative to other nest boxes, influenced the preference for a nest box, and how a sudden and marked change to the preferred box influenced the use of nest boxes by the hens. Groups (n = 12) of 15 Isa …
Studies on the prevalence of feather pecking in different commercial laying hen systems and its welfare and economic impacts are reviewed in the following paper. Current methods for controlling feather pecking include beak-trimming and alterations to light regimes, but these methods have significant disadvantages from the perspective of bird welfare. A substantial body of research …
Although the rearing period has an important influence on the development of feather pecking in laying hens, few studies have quantified the risk factors operating on commercial farms during this time and identified their long-term impact. Our aim was to conduct a longitudinal study to investigate the effect of rearing environment on feather pecking in …
Commercial laying hen chicks experience continuous light for up to 24 h/day in the first week of life. Under these conditions, active chicks disturb, and may direct feather pecks towards resting ones. Previous experimental work with small groups showed that both problems were reduced in chicks brooded by dark brooders (heaters). The current study aimed …
The environmental impacts of 2 alternative UK broiler production systems that aim to improve bird welfare (a lower stocking density indoor system and the same system combined with heat exchangers for ventilation air) were compared with the baseline standard indoor system of broiler production. Furthermore, the environmental impacts of egg production in the conventional battery …
Chemical communication is used by diverse organisms in a variety of contexts and can have strong fitness consequences for the individuals involved. However, despite the extensive use of birds as models for many research areas in biology, avian olfaction has been poorly investigated. Studies on bird species that lack well-developed olfactory organs and those investigating …
The ‘reward cycle’ conceptualises reward acquisition as a cyclic phenomenon divided into three motivational stages with related emotional or affective states. For feeding behaviour such a cycle consists of an appetitive stage characterised by foraging and exploration linked to emotions such as wanting and anticipation, a consummatory stage with eating behaviour linked to liking and …
Studies using classical conditioning have shown that hens display high frequencies of dopamine-controlled cue-induced anticipatory behaviours in the cue-reward interval when signalling mealworm rewards. However, it is not known whether anticipatory behaviours are reward specific, and whether the opioid system is involved in their control. The purpose of the present study was to investigate (1) …
Although, the incidence of frustration-related behaviours is influenced by frustration-provoking social and environmental conflicts, the occurrence of particular frustration-related behaviours associated with discriminatory learning remains controversial. For example, the assumption that frustration is associated with stress and stress may interfere with learning and memory is well established, but if the incidence of particular frustration-related behaviours …