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Environmental stimuli present during incubation can impact the behavior of birds post-hatch. To determine the effect of exposing broiler chicken embryos to light on fear-related behavior post-hatch, we conducted two experiments in which we incubated eggs under various light schedules, and then measured fear responses when the chickens (N = 720) were 3–6 wk of age. In Expt. 1, the incubation photoperiods were 0L:24D, 12L:12D, and 24L:0D, and tonic immobility (TI) and inversion (INV) tests were administered. In Expt. 2, the incubation photoperiods were 0L:24D, 1L:23D, 6L:18D, and 12L:12D; and an approach test (APPR) and an emergence (EMRG) test were administered in addition to TI and INV. In Expt. 1, both 12L:12D and 24L:0D had shorter latencies to right during TI (213.5 ± 23.7 and 231.8 ± 24.2 s, respectively) than 0L:24D (305.5 ± 26.1 s) and also wing flapped less intensely during INV (12L:12D 5.0 ± 0.1 wing flaps; 24L:0D 5.4 ± 0.2) than 0L:24D (5.7 ± 0.1). In Expt. 2, the 12L:12D birds once again had shorter latencies to right during TI (120.0 ± 16.5 s) and wing flapped less intensely during INV (4.7 ± 0.1 wing flaps) than 0L:24D (201.4 ± 24.9 and 5.5 ± 0.1, respectively). They also had shorter latencies to exit the dark box in EMRG (28.9 ± 3.3 s), and were less active (28 ± 2%), vocalized less (178.8 ± 9.3 times/3 min) and spent more time closer to the observer during APPR (63 ± 3%) than 0L:12D (42.9 ± 5.0 s, 35 ± 3%, 211.2 ± 10.4 times/3 min, 51 ± 3). The 1L:23D and 6L:18D showed some reductions in fearfulness compared to 0L:24D, but these were not consistent across tests. The 6L:18D and 12L:12D birds demonstrated lateralization in the direction to leave the box in EMRG, whereas 1L:23D and 0L:12D exited left or right at chance levels. The results of these experiments indicate that providing at 12 h of light stimulation daily during embryogenesis results in long-term reductions in fearfulness as measured by multiple tests, and that this may be related to cerebral lateralization. In conjunction with other research, these findings show that light exposure during embryogenesis has important implications for behavioral phenotypes and welfare in chickens.

The effects of beak condition on ectoparasite populations and preening in laying hens were investigated. Beak-trimmed and beak-intact caged Hy-Line W-36 hens were infested with either chicken body lice or northern fowl mites using a 2 × 2 factorial design with 4 replicate cages (each containing 2 hens)/treatment: 1) BTL (beak-trimmed lice-infested); 2) BTM (beak-trimmed mite-infested); 3) BIL (beak-intact lice-infested); and 4) BIM (beak-intact mite-infested). Mite scores and lice numbers were estimated weekly. Hens were video recorded the wk before infestation and at wk 6 and 9 post-infestation. Time spent preening on 6 body areas and in total were analyzed using a repeated measures ANOVA. There was a wk × beak condition interaction for lice loads, with BTL harboring approximately 17 times more lice than BIL from wk 7 to 10 post-infestation (P < 0.0001). Beak condition affected mite loads (P < 0.0001), with BTM having a higher mite score (3.8 ± 0.26) than BIM (1.4 ± 0.26). At peak infestation, BTL spent more total time preening (P = 0.02, s ± SE: 232.1 ± 37.6) than prior to infestation (33.9 ± 37.6) and directed their preening behavior towards the vent. In contrast, BIL (73.9 ± 37.6), BTM (9.4 ± 1.6), and BIM (8.6 ± 1.6) did not increase total time spent preening over pre-infestation levels (103.6 ± 37.6, 5.8 ± 1.6, 6.7 ± 1.6 respectively), although BTM did redirect their preening behavior toward the vent. This study confirmed previous studies showing that an intact beak is important for reducing ectoparasite infestations. Preening behavior increased in response to lice infestation, but only in beak-trimmed hens; preening behavior and louse load were correlated at peak infestation. In contrast, mite infestation did not lead to increased preening, and there was no correlation between preening and mite load. However, both lice- and mite-infested hens directed preening behavior predominantly towards the vent where these parasites are typically found.

This paper is an integral part of the special publication series that arose from the multidisciplinary and multi-institutional project of the Coalition for Sustainable Egg Supply (CSES). The CSES project involves 3 housing systems for egg production at the same research farm site in the Midwest, USA, namely, a conventional cage (CC) house, an aviary (AV) house, and an enriched colony (EC) house. The CC house (141.4 m L × 26.6 m W × 6.1 m H) had a nominal capacity of 200,000 hens (6 hens in a cage at a stocking density of 516 cm2/hen), and the cages were arranged in 10 rows, 8 tiers per cage row, with a perforated aisle walkway at 4-tier height. The AV house (154.2 m L × 21.3 m W × 3.0 m H) and the EC house (154.2 m L × 13.7 m W × 4.0 m H) each had a nominal capacity of 50,000 hens. The AV house had 6 rows of aviary colonies, and the EC house had 5 rows of 4-tier enriched colonies containing perches, nestbox, and scratch pads (60 hens per colony at a stocking density of 752 cm2/hen). The overarching goal of the CSES project, as stated in the opening article of this series, was to comprehensively evaluate the 3 egg production systems from the standpoints of animal behavior and well-being, environmental impact, egg safety and quality, food affordability, and worker health. So that all the area-specific papers would not have to repeat a detailed description of the production systems and the management practices, this paper is written to provide such a description and to be used as a common reference for the companion papers.

Although environmental conditions during incubation can affect poultry welfare, one factor often overlooked in the commercial incubation of eggs is light. Light stimulation during embryonic development is now known to affect the physiology and behavior of broiler (meat) chickens post-hatch, but little is known about the pattern of exposure needed to produce these effects. We determined how often naturally incubated eggs were exposed to light by giving 10 broody Junglefowl × New Hampshire Red hens a nestbox containing five fertile eggs and a light sensitive data logger which recorded nest attendance by determining whether light was reaching the eggs. On average hens stayed on the nest without leaving for 14.3 of the days of the 21-day incubation cycle, although they did leave periodically, particularly during the last week. Utilizing this information, we then investigated how the timing of light exposure during incubation affected fear and stress responsiveness post-hatch in broiler chickens. Eggs were either not exposed to light (0DL), or exposed to light throughout incubation (21DL) or during only either the last 2 weeks (14DL) or the last week (7DL) of incubation. Lighting pattern had a significant effect on all parameters measured, with the most consistent differences found between 0DL and 21DL. For the fear measures, the 0DL birds had a longer latency to emerge during an emergence test (62.7 versus 37.2 s), a longer latency to right during a tonic immobility test (223.8 versus 107.2 s), wing-flapped more intensely during an inversion test (7.03 versus 6.4 flaps/s), and vocalized more during an isolation test (172.7 versus 127.1/3 min) than the 21DL. For the stress measures, 0DL had a lower IgG titer (52,683 versus 97,375 units) and greater corticosterone response (1.18 versus 0.55 ng/mL) to the crating stressor than 21DL, and showed more composite asymmetry (1.96 versus 1.49 mm). The 14DL and 7DL groups were generally intermediate. Unlike dark-incubated chicks, all light-stimulated groups showed lateralization of escape direction during the emergence test, suggesting that light-induced cerebral laterality could play a role in the observed effects. However, the direction of lateralization differed depending upon timing of exposure. These results confirm the importance of light stimulation during incubation on the later behavior and physiology of broiler chickens, but also indicate that providing light only during the last week of incubation, which would coincide with the maximum light stimulation provided by hens’ excursions from the nest, is insufficient to produce these effects.

Social enrichment is increasingly employed to improve the welfare of laboratory animals, including rabbits. However, the high levels of injurious aggression that can occur when unfamiliar adult rabbits are introduced to one another are a barrier to implementing social housing. One factor that could affect aggressive interaction is the size of the enclosure in which the animals are introduced, although this has never been tested in rabbits. We evaluated the aggressive and affiliative behavior of 11 pairs of unfamiliar adult female New Zealand White rabbits during 1-h trials. Using a balanced repeated measures design, pairs were tested in a smaller (Small) enclosure the size of a double cage (0.76 m × 1.22 m × 0.61 m) and a larger (Large) enclosure (1.22 m × 1.22 m × 0.61 m), both of which contained PVC barriers that allowed contact but prevented injury. There were no main effects of treatment or treatment order on aggressive or affiliative behavior, but there were significant interaction effects (P = 0.01). During their first trial, pairs tested in the Large enclosure showed higher levels (P = 0.07) of affiliative behavior (mean number = 37.6 ± 5.0) and lower levels (P = 0.02) of aggressive behavior (back-transformed mean number = 1.1) than pairs tested in the Small enclosure (20.7 ± 3.0 and 3.5, respectively). During their second trials, pairs behaved as they did during their first trial, resulting in the opposite pattern: significantly more aggressive behavior in the Large enclosure than the Small enclosure (P = 0.002). In total, there were 47 bites observed among does first introduced in the Small enclosure, as compared to only one in the pairs first introduced in the Large enclosure. Overall, these findings indicate that the Large enclosure was effective at reducing aggression when rabbits were unfamiliar to one another, but that behavior during a subsequent interaction was determined by prior experience rather than enclosure size. More research is needed to determine whether does’ short-term behavior in an experimental apparatus is predictive of long-term pair housing success.

Furnished cages for laying hens often contain an Astroturf (AT) pad which may be sprinkled with feed to promote foraging and dustbathing. We evaluated AT and AT plus feed (ATF) to determine if hens use these substrates for dustbathing. Hens ( N = 30) without prior exposure to substrate were housed singly in cages at 34 weeks of age. Using a 3 × 3 Latin square design, groups of 10 hens were provided with a dustbox containing either sand (control), an AT pad, or an AT pad with 200 g of feed (ATF) delivered daily, with three 20-day treatment Periods. The treatment order was: sand–ATF–AT (1); ATF–AT–sand (2); AT–sand–ATF (3). Behavior was recorded for 8 or 9 days each Period, from 11:00 to 22:00 h. Three measures of dustbathing were evaluated: bout number per day, bout length, and total time spent dustbathing per day. Data were collected and processed to evaluate dustbathing activity in the substrate, on the wire floor and in both locations combined (overall). Data were analyzed using the GLM or Kruskal–Wallis and Dwass-Steel-Critchlow-Fligner tests. Although there were some differences in statistical significance between Periods, in general hens provided with sand exhibited fewer bouts both overall and on wire, and longer bouts both overall and one wire, than AT or ATF hens, and longer bouts both overall and in substrate than AT. Hens with sand also spent significantly (all P ≤ 0.04) more time dustbathing on substrate (median min = 18.71 ± 5.16) and less time on wire (0.59 ± 1.56) than AT (0.33 ± 2.62 and 13.39 ± 7.15, respectively) and ATF (2.05 ± 4.43 and 11.26 ± 4.37, respectively) treatments during Period 1, and also more time dustbathing on substrate (7.66 ± 8.13) than hens in the AT treatment (0.00 ± 2.52) during Period 2. Exposure to AT and ATF during the first two treatment periods reduced hens’ use of sand during the third treatment period, with only 11% of bouts occurring in sand during Period 3 as compared to 64% and 41% during Periods 1 and 2, respectively. These findings demonstrated that AT did not provide an adequate dustbathing substrate, even with the addition of feed, as hens were less likely to dustbathe on both AT and ATF than sand, and were also less likely to dustbathe on sand if they were initially exposed to AT and ATF as dustbathing substrates.

Day length and intensity are commonly manipulated aspects of the light environment in commercial broiler production. Both influence circadian rhythms, but it is unclear if they do this independently or synergistically. The effect of light:dark (20L:4D, 16L:8D) and intensity contrasts (1 lx:0.5 lx, 200 lx:0.5 lx) on broiler behavior and health (n=1,004, 4 replicates/treatment) was evaluated. Activity was measured using passive infrared detection, and feeding activity was measured by the amount of feed consumed/h over one 24-h period each week. Broilers were gait scored and weighed at 6 wk of age. Following euthanasia, eyes were dissected from 30 birds/treatment. Behavior and performance were analyzed using the GLM, gait score using the Kruskal-Wallis test, and eye measures using a MANOVA. The 200 lx birds were more active (P=0.03) and fed more (P=0.001) during the photophase but were less active (P=0.02) and fed less (P

To encourage nest use in breeder poultry flocks, it is important that nest boxes are attractive. Few studies have evaluated factors affecting nest attractiveness to ducks. We assessed the effects of nest box experience (Experiments 1 and 2) and features of nests, including degree of enclosure (Experiments 1 and 2) and the presence of an egg (Experiment 3), on nest site selection by sexually mature Pekin ducks. The hens were tested individually in pens containing different nest box choices. Nest preferences were determined based on the locations of 14 successively laid eggs. Ducks in Experiment 1 were provided with nest box access prior to the onset of lay (20 weeks of age, EXP group, N = 12) or at the time of preference testing (35 weeks of age, DELAYED-EXP group, N = 12). Delaying nest box access by 15 weeks did not significantly affect the proportion of eggs laid in nest boxes rather than on the floor ( P = 0.40). Regardless of experience ducks laid more than 66% of their eggs in nest boxes offering a higher degree of enclosure. Ducks in Experiment 2 were reared with either open-top (OP, N = 12) or closed-top (CL, N = 12) boxes. Regardless of rearing condition, ducks preferred boxes with the highest level of enclosure offered. Ducks laid twice the expected proportion (25%) of eggs in CL boxes with curtains ( P = 0.0004). CL boxes without curtains were used as predicted by chance, 25% ( P = 0.746), while OP boxes with ( P = 0.009) and without ( P = 0.015) curtains each contained only half the expected number of eggs. Ducks in Experiment 3 were provided with two nest boxes, one of which contained the egg laid the previous day. Each day, the newly laid egg was marked and either placed back in the nest box where it was found (HANDLED, N = 12) or moved into the adjacent nest box (MOVED, N = 12). Ducks in HANDLED and MOVED laid 97.6% and 79.8%, respectively, of their eggs in boxes containing the previous day's egg. While ducks in HANDLED were consistent in their choice throughout the test, those in MOVED developed the preference over time ( P = 0.039), suggesting that the preference for laying in a nest containing an egg may be influenced by experience. These results indicate that nest box enclosure and the presence of an egg are important in determining the nesting choices of Pekin ducks. Incorporating these features into nest boxes may be useful for increasing consistency of nest use in breeder duck flocks.

1. The effect of light intensity on behavioural synchrony and rest in broilers was investigated by randomly assigning 504 Cobb chicks to environmental chambers at low (5 lux), moderate (50 lux), or high (200 lux) daytime illumination under a 16 h L : 8 h D light cycle. We hypothesised that behavioural synchrony and resting behaviour would be affected by light : dark amplitude, and predicted that broilers reared at higher intensities would show increased synchrony and thus have fewer, but longer, resting bouts during the scotophase, since these bouts would be less likely to be interrupted by active birds. 2. Digital recordings were made for 48 h from weeks 3 to 5 of age, and scan samples taken of 11 behaviours at 15-min intervals. Z-scores for the amount of synchronisation were calculated using the kappa coefficient of agreement. Frequency and length of resting bouts and the number of resting bout interruptions by flockmates were also calculated from continuous observations of 4 focal broilers per pen. 3. Resting and sitting behaviour were significantly synchronised or showed a strong trend towards synchronisation in all treatments during the 3 weeks of observation. There were significant treatment differences in the degree of synchrony for preen, eat, rest and forage, with broilers reared in 200 lux showing the greatest degree of synchrony. 4. During the scotophase, broilers reared with high illumination had fewer, longer, and less interrupted bouts of resting than those reared with moderate or low illumination. During the photophase, broilers in the low-illumination treatment had more frequent, longer, and more interrupted resting bouts than those in the moderate or high illumination treatment. 5. In conclusion, rearing broilers under a 16 h L : 8 h D photoperiod with high daytime light intensity resulted in greater behavioural synchrony in the flock, with the potential to improve welfare by increasing uninterrupted resting behaviour during the dark phase.

Light management is a critical component of production for intensively housed animals. To increase productivity, broiler chickens are often raised commercially in houses that are dimly illuminated on a near-continuous basis. There have been relatively few studies examining the effects of light intensity on the behaviour of broilers. We evaluated the time budgets of broilers (N = 464) housed under one of three photophase light levels (5, 50 or 200 lx) chosen to produce low, moderate or high illumination contrasts with the scotophase light level (1 lx). There were four replicate pens of broilers per treatment. We recorded behaviour for 48 continuous hours during weeks 3, 4, and 5 of age and analysed the time broilers spent exhibiting eight behaviours and two behavioural categories (inactive and active) during the overall photoperiod, photophase and scotophase. There were only two main effects of light intensity on behaviour during the overall photoperiod: 5 lx broilers preened and foraged less than the 50 (P = 0.03, P = 0.03, respectively) and 200 lx birds (P

Environmental stimuli present during incubation can affect the behavior and health of birds posthatch. Commercial broiler chickens are often incubated in complete darkness, receiving light only intermittently when the incubator is opened. To determine the effect of providing light during the prehatch period, we incubated Cobb broiler eggs (n = 664) under continuous light (24L:0D), no light (0L:24D), or 12 h of light (12L:12D); the light level was 550 lx. Various parameters were measured posthatch in these broilers (n = 506), which were raised in floor pens on a 12L:12D regimen. There were no incubation treatment differences in hatchability, mortality, growth, feed consumption, feed conversion ratio, gait score, overall feeding behavior activity, or general behavioral activity. However, broilers hatched from eggs incubated under 24L:0D or 12L:12D had greater feeding activity (P < 0.05) than the 0L:24D broilers during the 2 h after the lights came on. Eye dimensions did not differ between treatments, but the eyes of the 12L:12D broilers weighed less (P < 0.05) than those of the other treatments. Broilers incubated under 0L:24D had a greater level of composite physical asymmetry (1.87 +/- 0.11 mm), considered to be an indicator of developmental stress, than did 12L:12D (1.57 +/- 0.09 mm; P = 0.05) broilers; they also tended to have more composite asymmetry than 24L:0D (1.62 +/- 0.11 mm; P = 0.10) broilers. The results of this study indicate that providing light during incubation has no detrimental effect on production or health of broilers, but does have potential benefits in terms of reducing the effects of stressors associated with production and growth.

Environmental enrichment is an important strategy to improve the welfare of laboratory animals. Running wheels might serve as enrichment devices for laboratory mice, since mice use them extensively when they are provided. However, competition among group-housed mice for such highly preferred enrichment devices could also lead to injurious aggression. We therefore assessed the effects of providing a running wheel-igloo enrichment on the social behaviour of group-housed male mice. CD-1 (ICR) mice (n = 60, 20 per treatment) were housed in standard polycarbonate cages (five mice per cage) for 2 weeks (BASE), and then placed in either: (1) a standard cage with bedding (CONTROL), or (2) same as CONTROL, but with the addition of a Bio-Serv® mouse running wheel-igloo (WHEEL) or (3) same as WHEEL, but with the running wheel glued in place so that it could not rotate (FIXED). Social behaviour and dominance ranks were assessed at the end of BASE and 2 weeks after imposition of treatments. There was increased escalated aggression in both enriched cages (FIXED, Tukey: T8 = −8.31; P = 0.0003; WHEEL, Tukey: T8 = −4.577; P = 0.0153), and decreased stereotypy in WHEEL (Tukey: T8 = 4.226; P = 0.0237). There was also a decrease in dominance hierarchy linearity in enriched treatments (FIXED, Tukey: T9 = 3.653; P = 0.0433; WHEEL, Tukey: T9 = 6.273; P = 0.0014) and a negative correlation between hierarchy linearity and escalated aggression overall (GLM: F1,7 = 61.41; P < 0.001; partial r = 0.90). Thus, providing the running wheel-igloo enrichment had a negative effect in that it increased potentially injurious aggression. Additionally, the decrease in hierarchy linearity suggests that the social structure in enriched groups was disrupted. The cause of the decrease in cage stereotypies in WHEEL is unknown, but could be because these stereotypies were re-directed towards stereotypic wheel-running, or because wheel-running reduced frustration due to limited opportunities for exploratory locomotion or caused a shift in the behavioural time budget. Despite this decrease in stereotypy, this form of enrichment is not beneficial for group-housed male CD-1 mice due to the associated increased aggression. However, female mice or males of less aggressive mouse strains might respond differently, and singly housed mice should generally benefit from such enrichment.

The Welfare Quality(®) Assessment protocol for poultry ( WQA: ) provides animal-based measures allowing welfare comparisons across farms and housing systems. It was used to compare Lohmann LSL Classic White hens housed in an enriched colony ( EC: ), aviary ( AV: ), and conventional cage system ( CC: ) on a commercial farm over 2 flock cycles. Hens (n = 100/system) were scored on a variety of measures. A baseline measurement was made at placement at 19 wk of age for 1 flock, since AV hens had been reared in an aviary pullet facility ( AVP: while EC and CC hens were reared in a conventional pullet facility ( CCP: ). Hens in all systems were then assessed at 52 and 72 wk of age. Necropsies were performed on all mortalities 1 wk before and after the WQA sampling. WQAs were analyzed using Mann-Whitney U and Kruskal-Wallis tests for prevalence and Fisher's exact tests for severity. There was an effect of rearing, with AVP having shorter claws (P = 0.01), dirtier feathers (P = 0.03), and more keel abnormalities (P

Environmental enrichment falls into four general categories: foraging opportunities, structural complexity, sensory stimulation/novelty, and social companionship. Each may have distinct behavioural effects. We examined the use of these four enrichment types, and their effects on activity budgets (foraging, general activity, pacing), social proximity preference (time spent observing companions through a window), and fear (flight distance in a predator surprise test, consumption of novel food) in adult Japanese quail. Foraging and structural enrichments were used extensively (29 and 26% of scans, respectively), as were the dustbaths available in all pens (16%). Use of enrichments and the dustbath was consistent over 24 h and over 17 d (partial r > 0.42, p F 3,89 = 5.66, p F 3,89 = 4.75, p F 3,89 = 6.33, p = 0.001). Novelty enrichment had no significant effects. Social housing reduced use of enrichments (enrichment treatment × housing type F 3,89 = 3.30, p F 1,89 = 4.59, p F 1,45 = 5.43, p F 1,45 = 7.88, p F 1,89 = 13.35, p F 1,89 = 38.18, p F 1,89 = 34.83, p

Despite their gregarious nature, rabbits used for research are often housed individually due to concerns about aggression and disease transmission. However, conventional laboratory cages restrict movement, and rabbits housed singly in these cages often perform abnormal behaviors, an indication of compromised welfare. Pairing rabbits in double-sized cages could potentially improve welfare by providing both increased space and social stimulation. We compared the behavior of female New Zealand White rabbits ( Oryctolagus cuniculus ) housed either individually ( N =4) in cages measuring 61 cm ×76 cm ×41 cm or in non-littermate pairs (four pairs) in double-wide cages measuring 122 cm ×76 cm ×41 cm. The rabbits were kept under a reversed photoperiod (lights on 22:00–12:00 h). Each rabbit was observed five times per week for 5 months, using 15-min focal animal samples taken between 08:00–09:00, 12:00–13:00, and 16:00–17:00 h. Data were analyzed using a repeated measures General Linear Model (GLM). Over the 5 months, individually housed rabbits showed an increase in the proportion of the total behavioral time budget spent engaged in abnormal behaviors (digging, floor chewing, bar biting), from 0.25 to 1.77%, while pairs remained unchanged at 0.95% (treatment×time interaction, F 1,24 =4.60; P ≤0.0422). Paired rabbits engaged in more locomotor behavior ( F 1,6 =16.49; P ≤0.0066) than individual rabbits (average proportions of time budget: 2.71 and 0.70% for paired and individual rabbits, respectively), which may be important because caged rabbits are susceptible to osteoporosis and other bone abnormalities due to the restricted ability to move. Time spent feeding and body weights of dominant and subordinate rabbits in a pair did not differ, indicating that food competition was not a problem, and paired rabbits were often observed in physical contact (26.7% of data records) although the size of the cages allowed physical separation. Aggression between pairmates did not increase significantly during the study. However, one pair did have to be separated at the end of the study due to bite wounds from persistent aggression. Thus, although methods for decreasing injurious aggression require further investigation, the beneficial effects of pair housing in decreasing abnormal behaviors and increasing locomotion suggest that pair housing should be considered as an alternative to individual housing for caged laboratory rabbits.

It has been suggested that isolation from conspecifics may contribute to the development of abnormal behaviors that are common in captive parrots, including stereotypy, feather plucking, excessive fearfulness and aggression (e.g. [Proceedings of the European Symposium on Bird Diseases, Beerse, Belgium (1987), p. 98; Kleintierpraxis 38 (1993) 511]). Thus, we assessed the influence of isosexual pair housing on the development of these behaviors, as well as the incidence of illness and injury, in young Orange-winged Amazon parrots (Amazona amazonica). Parrots (n=21) were parent raised to 6 months of age and then housed either singly or in isosexual pairs. All cages included inanimate enrichments that were changed regularly, and all parrots were handled regularly. Behavioral activity was recorded 0,3,6,9 and 12 months after the parrots were housed in the experimental cages, and responses (e.g. willingness to approach, tolerance to touch, flight distance) to familiar and strange human handlers and to novel objects introduced into the home cage were recorded periodically. Paired parrots used their enrichments more (GLM: F1,10=13.74; P=0.004), and spent less time screaming (F1,10=4.90; P=0.051), less time preening (F1,10=5.12; P=0.047), and less time inactive (F1,10=9.24; P

Although many authors have suggested that the quality of the cage environment contributes to the development and performance of psychogenic feather picking by parrots, there is little scientific evidence for this relationship. In chickens, there is an established relationship between absence of foraging opportunity and the performance of a similar behavior, feather pecking. Thus, we assessed whether providing environmental enrichments designed to facilitate foraging behaviors would prevent or reduce the development of feather picking behavior by parrots, as evidenced by superior feather condition. Two groups of eight parrots were parent-reared to weaning and then housed singly in either enriched or unenriched cages for 48 weeks. In the enriched condition, a unique combination of one foraging and one physical enrichment was presented to each parrot weekly. In both groups, feather condition was quantified using a 10-point scale. The provision of enrichments led to an improvement in feather condition over 48 weeks in the enriched group, while feather scores in the control group decreased significantly (repeated measures GLM: F 1,46 =5.59; P =0.022) during this same period, indicating that feather picking behavior had developed in this group. In the second part of this study, the control group was transferred to the enriched treatment for a period of 16 weeks. During this period re-feathering occurred and feather scores improved significantly, indicating that feather picking behavior had decreased (repeated measures GLM: F 1,53 =35.57, P

A presumed function of dustbathing behavior is to remove ectoparasites. Providing dustbathing substrates in furnished cages for laying hens might therefore offer an alternative to pesticide use to reduce ectoparasite populations. We investigated the effectiveness of dustbathing substrates for controlling northern fowl mites in individually caged beak-trimmed White Leghorn hens (N = 32). Each cage contained a 32 cm × 32 cm plastic tray that was either: (1) filled with 1200 g of sand (SAND); (2) empty (CONTROL); (3) covered with Astroturf (AT); or (4) covered with AT on to which 150 g of feed was delivered daily (ATF). AT and ATF are used in the dustbathing/foraging area of many newer commercial furnished cages. Hens were infested with approximately 35 mites at 25 weeks of age. Mite numbers were estimated weekly. Time spent dustbathing and dustbathing bout numbers and lengths in the tray and on the wire cage floor were determined from video recordings made for 2 consecutive days from 12:00 to 20:00 h immediately before and after infestation and at weeks 1, 3, 5, and 7 post-infestation. Data were analyzed using a repeated-measures ANOVA in SAS. Treatment did not influence the total time spent dustbathing (average across substrates: 11.3 min). However, there were treatment effects on the time spent dustbathing in the trays (F2,21 = 3.67, P = 0.043) and on wire (F2,21 = 7.68, P = 0.031). SAND and ATF hens spent more time dustbathing in the trays (11.4 and 9.1 min, respectively) than AT (2.3 min), and CONTROL and AT hens spent more time dustbathing on wire (11.6 and 4.7 min, respectively) than ATF (0.4 min). There was a treatment effect on infestation (F3,28 = 3.08, P = 0.04), with ATF having more mites (back-transformed mean = 1500) than AT (330), and with SAND (460) and CONTROL (447) intermediate. This study confirmed that the substrate type affected dustbathing behavior. SAND was a preferred dustbathing substrate but was not effective for controlling mite numbers, nor was the time spent dustbathing in any substrate or in total influenced by infestation levels. Our data also suggest that adding feed to the AT pad in furnished cages might lead to increased mite numbers in infested hens. The reason for this effect is unclear, but could be due to feed particles contributing to a change in feather structure that creates a more favorable mite habitat.

Two states in the United States now have legislation requiring that laying hens be provided with sufficient space to perform particular behaviors. To provide a framework for translating these performance standards into a space requirement, kinematic analysis was used to measure the amount of space needed for White Leghorn hens to stand, turn around 180°, lie down, and wing flap. Hyline W-36 hens (n = 9) were marked on the tops of their heads and the tips of both wings and 3 toes with black livestock marker. Each hen was then placed in a floor pen (91.4 × 91.4 cm) and filmed using 2 high-speed cameras. The resulting images were processed using a software program that generated 3-dimensional space use for each behavior. Because none of the hens lay down in the test pen, the 2-dimensional space required for lying was determined by superimposing a grid over videos of the hens lying down in their home cages. On average, hens required a mean area of 563 (± 8) cm2 to stand, 1,316 (± 23) cm2 to turn around, 318 (± 6) cm2 to lie down, and 1,693 (± 136) cm2 to wing flap. The mean heights used were 34.8 (± 1.3) cm for standing, 38.6 (± 2.3) cm for turning, and 49.5 (± 1.8) cm for wing flapping. However, space requirements for hens housed in multiple-hen groups in cage or noncage systems cannot be based simply on information about the space required for local movement by a single hen. It must also incorporate consideration of the tendency of hens in a flock to synchronize their behaviors. In addition, it must include not just local movement space but also the space that hens may need to use for longer-distance movements to access resources such as food, water, perches, and nest boxes.

This experiment was conducted to determine the effect of elevated plasma corticosterone (CORT) levels on meat quality characteristics. Male broilers (Arbor Acres) were either 1) fed a diet containing corticosterone (CORT) prior to processing, 2) transported by truck for 3 h before processing, or 3) processed without either of the above treatments. Six crates of birds (10 birds per crate; two crates per treatment) were stunned or killed using CO2 gas. Six birds per crate were processed and blood samples were collected during exsanguination for plasma CORT analysis. Meat samples were collected from carcasses either at 20 min or at 4 h post-mortem. At each sampling time (ST), Pectoralis superficialis samples were collected and either individually quick frozen (IQF) in liquid nitrogen or aged on ice (AOI) for 24 h prior to pH, ratio of inosine to adenosine nucleotides (R-value), cooking loss, shear value, and color analyses. The IQF Biceps femoris samples were used for pH, R-value, color, and heme pigment analysis. Mean (+/- SEM) CORT concentrations were 12.9+/-2.57, 11.7+/-1.38 and 7.9+/-0.79 ng/mL, respectively, in the CORT, transported, and control groups. There were significant treatment by ST (P < 0.05) and ST (P < 0.001) effects on the R-value of IQF P. superficialis samples. The CORT group had the highest L* value (P < 0.01) and the lowest a* value (P < 0.06). There was also a significant main effect of ST on shear values (P < 0.05) of AOI P. superficialis samples, with the means higher at 4 h than at 20 min post-mortem. The R-value of IQF B. femoris samples was markedly influenced by treatment (P < 0.001) and ST (P < 0.001). The results indicate that artificially elevating circulating CORT concentrations results in lighter meat color in broilers.

1. Experiments were conducted to study the welfare and meat quality effects of shackling. In experiment 1, broilers with or without leg problems were shackled (S) for 4 min on a moving line and blood sampled; or handled (H), returned to the crate and sampled after 4 min; or sampled immediately after removal from the crate (control, C). 2. Plasma corticosterone (CORT) concentrations, as measured by radioimmunoassay, were highest in S and lowest in C, while the H group was intermediate. Leg problems had no effect on CORT. 3. In experiment 2, tonic immobility (TI) was induced in broilers after 2 min inverted handling to determine fear responses. One week later, the birds were fasted, transported and then shackled on a moving shackle line for 0, 1, 3 or 4 min, then unshackled and blood sampled. Wing flapping during shackling was also quantified. 4. Shackling time did not influence CORT concentrations. There was a negative correlation (r = -0.714) between CORT and wing flapping duration in the 1 min shackling treatment. There was no relationship between TI and wing flapping or CORT. 5. In experiment 3, broilers were exposed to two food withdrawal (FW) times (food withdrawn overnight or during crating only) and held for 4 h prior to processing, shackled (0, 2 or 4 min shackling time, ST), and then killed by exsanguination. Blood samples were collected during the neck-cut. Pectoralis superficialis and Supracoracoideus samples were either collected after 15 min and individually quick frozen (IQF) in liquid nitrogen or collected at 4 h post mortem from carcases chilled on slush ice (COI). 6. CORT increased significantly with increased ST. There was a FW x ST interaction effect on the initial pH of fillets. ST influenced the b*, chroma and Hue values of the COI fillets. FW influenced the L* and Hue values of both IQF and COI fillets as well as the a* value of the COI fillets. 7. In summary, CORT increased with shackling time when birds were held after transport. FW and ST also influenced the colour of fillets, although it is not clear whether these changes are perceptible to the consumer. The duration of wing flapping during shackling did not appear to be related to fearfulness, although it was influenced by properties of the shackle line. We suggest that there be a maximum time lapse between shackling and stunning or killing of 2 min to minimise stress and meat quality changes.

Experiments were conducted to determine 1) whether different crating durations influence stress responses and meat quality in broilers, and 2) whether holding crated broilers after transport influences corticosterone (CORT) levels and meat quality. In a preliminary experiment, male broilers (n = 50) were held in crates (10 birds per crate) for either 0, 1, 2, 3, or 4 h prior to processing. Crating duration did not affect plasma CORT level, cooking loss, shear value of breast or thigh muscles, or carcass skin discolorations. Crating duration also did not affect the color (L*, a*, b*, chroma, and hue angle) of breast meat, but did change the color of thigh meat, with samples from the 3 h crating group having the highest hue values (P0.01). Corticosterone concentrations and hue values of thigh samples were positively correlated (P0.05, r = 0.244). In Experiment 1, broilers (n = 36) were crated for either 1 or 3 h, with 9 birds per crate. Crating time did not influence plasma CORT, epinephrine, or norepinephrine concentrations, initial pH, color, or texture of breast and thigh meat samples. In Experiment 2, broilers were crated (nine birds per crate) early in the morning and transported 3 h to the processing facility by truck. Nine crates of birds were held in a dark quiet place for 4 h prior to processing (H) and the remaining nine crates were processed immediately (NH). Corticosterone levels were significantly lower (P0.01) in the H group than in the NH group. Initial pH of thigh meat of the H group was also significantly lower (P0.01), although breast meat pH was not affected by treatment. Holding had no effect on shear values, color (breast and thigh), or total heme concentration (thigh). There was a significant correlation (P0.01, r = 0.302) between CORT levels and hue values of thigh meat. These results suggest that higher preslaughter stress levels in broilers could influence the color of thigh meat, although overall meat quality was not affected under the conditions of this study.

Providing light during incubation has been shown to decrease bilateral physical asymmetry of broilers posthatch, which may indicate that early light stimulation reduces later stress susceptibility. This experiment evaluated the effects of lighting during embryogenesis on other measures of stress responsiveness in broilers. Cobb 500 eggs (n = 1,404) were incubated under 0L:24D, 1L:23D, 6L:18D, or 12L:12D; the light level was 550 lx. The broilers were then raised in floor pens under a 12L:12D lighting regimen, and various stress parameters were measured during wk 3 to 6 of age. There was an effect of incubation lighting regimen on posthatch stress responses. Following 1 h of crating, the change in corticosterone (CORT) concentration was less in the 12L:12D (-0.06 ng/mL, P0.05) treatment than all other treatments (pooled mean = 0.24 ng/mL); however, there were no treatment differences in CORT response to adrenocorticotropic hormone administration (pooled mean pre- vs. 1 h postadministration = 17.5 ng/mL, P0.05). Anti-keyhole limpet hemocyanin titers were higher in the 12L:12D birds (92,395 units/mL; P0.05) than all other treatments (pooled mean = 68,407 units/mL) on d 1 postcrating. Additionally, composite asymmetry scores were lower in the 12L:12D treatment (0.92 mm) than all other treatments (pooled mean = 1.14 mm, P0.05). These results demonstrate that providing 12 h of light per day during incubation can reduce the stress susceptibility of broilers posthatch.

Hen performance can be affected by many interacting variables related to cage design, such as floor area, height, tier arrangement, and feeder and drinker type and placement within the cage. Likewise, features of house design such as waste management and lighting can also affect hen productivity. The influence of these design aspects on hen performance has not been fully assessed. Determining the effects of numerous, interacting variables is impractical in a traditional experiment; therefore, an epidemiological approach, using variability in cage and house design among and within commercial producers, was employed to identify features that affect egg production and egg weight. A universal cage measurement system was created to calculate cage design variables. A database for recording information on cage design, resource location, waste management, environmental conditions, and hen productivity was developed. Production outcomes were assessed from placement to 60 wk of age in White Leghorns (n = 165-168 houses). Using GLM, a statistical model was identified that best described the variance in egg traits. Eggs/hen-housed increased with greater feeder space allocation (P = 0.031); taller cages (P = 0.029); rear (vs. front) drinker location in vertical cages (P = 0.026); and regular removal of manure from the house (P = 0.005). Case weight of eggs was greater in A-frame houses where manure was removed regularly instead of being left in the house (P < 0.001); with increasing cage floor slope (P = 0.001); in cages where drinkers were placed more toward the front or back of the cage as compared with the middle of the cage (P < 0.001); with more space/hen (P = 0.024); and with higher caloric intake (P < 0.001). Perhaps because of its negative correlation with egg production, case weight of eggs increased with less feeder space allocation (P = 0.004) and shorter cage heights (P < 0.001). These results reveal important effects of feeder space, floor space, cage height, drinker position, and waste management on hen productivity.

This part updates the underlying report: The welfare of chickens kept for meat production (2000, available at http://ec.europa.eu/food/fs/sc/scah/out39_en.pdf).

Since certain colors are aversive to birds, it might be possible to use dyes to prevent birds from consuming agricultural seeds and pesticide granules. The effectiveness of eight dyes in repelling food consumption in a gamebird, the northern bobwhite (Colinus virginianus), was therefore evaluated. Forty adult birds were tested using a two-cup procedure to measure avoidance of dyed feed relative to undyed feed for 5 days. Pairs of feeds treated with different dyes were also tested to determine their relative repelency. Bobwhite hens avoided dyed feed significantly more than did bobwhite cocks. Hens avoided feed dyed certain shades of red, orange, blue-green, whereas cocks did not avoid feed of any color. Hens became largely habituated to food dyed colors other than red or orange within 5 days, suggesting that the initial avoidance was caused by neophobia. The more persistent avoidance of red and orange dyes may be evidence of unlearned aversions by bobwhites to the warning colors found in toxic prey. While bright red or orange dyes thus appear to be aversive to bobwhite hens, the lack of avoidance of these colors by cocks may limit their usefulness as avian feeding repellents.

The laying of eggs outside nest boxes is a common problem in poultry production systems. Fac- tors potentially contributing to floor laying by Pekin ducks were investigated. In a 2 × 2 factorial design, 16 groups of 18-wk-old ducks (8/group) were provided ac- cess to either 2 (4 ducks/box) or 8 (1 duck/box) closed- topped or open-topped nest boxes. Egg locations were recorded daily for 16 wk. Video analyses were used to determine the time of day eggs were laid on the floor when the ducks were 18 to 22, 26, 30, and 34 wk of age. An analysis of nontoxic dye deposition in the egg yolk was conducted on wk 30, 32, and 36 to determine the contribution of each duck to floor laying. The propor- tion of floor eggs was especially high early in the laying cycle, reaching 84 and 44% of eggs laid in pens offer- ing ratios of 4 ducks/box and 1 duck/box, respective- ly, when ducks were 22 wk of age. Repeated measures ANOVA revealed that although the proportion of floor eggs decreased over time (F3,9 = 29.29, P < 0.0001), it remained greater in the groups housed with 4 ducks/ box vs. 1 duck/box (F1,11 = 24.09, P = 0.0005). The proportion of floor eggs was not affected by box design (F1,11 = 0.08, P = 0.8). Not all available nest boxes contained eggs on a given day, and the distribution of eggs within the pen was clumped. However, it was un- likely that this reflected nest box location preferences because the locations of the eggs laid within the nest boxes changed over time. Taken together, these results suggest that floor laying by Pekin ducks may be caused in part by insufficient nest box availability. However, the clumped distribution of eggs suggests that other social factors, such as conspecific attraction, may also be important.

Four handling techniques commonly used with snakes and lizards in zoological park reptile collections were evaluated with respect to animal well-being. Adult male blue-tongued skinks (n=3) and ball pythons (n=4) were either handled gently, restrained manually, or container restrained for 10 min. The animals were then released into their enclosures for 15 min and blood sampled. At each sampling period, one animal served as an unhandled control. Plasma corticosterone (CS) levels, pre- and post-treatment locomotor and consummatory activities, and heterophil/lymphocyte ratios were determined. None of the parameters evaluated differed significantly among treatments with the exception of CS levels in container-restrained pythons (56.2±6.7 ng ml−1), which were higher (P

Insufficient feeder space for laying hens could increase competition at the feed trough, resulting in exclusion of low-ranking hens from the feeder. To test this hypothesis, the effects of feeder space allocation (FSA) on feeding behavior, aggression, feather scores, BW, and mortality were evaluated in a common commercial strain of egg-laying chickens. Beak-trimmed Hy-Line W-36 hens (n = 480) were obtained as pullets at 16.5 wk of age and housed in conventional cages on 4 tiers. Five pullets/cage were housed at a stocking density of 434 cm(2)/pullet and an FSA of 12.2 cm/pullet. After 1.5 wk of acclimation, baseline measurements were taken for 2 wk and then pullets were given either 5.8, 7.1, 8.4, 9.7, 10.9, or 12.2 cm of feeder space/hen (16 cages/treatment). Feeding behavior was evaluated in each cage over a 24-h period each month. For each hen, percentage of time spent feeding and synchrony (mean number of additional hens feeding at the same time) were determined and scores were averaged for each cage. For each cage, feeder switching (number of observations in which hens changed from feeding to not feeding) and feeder sharing (probability that feeder access was equally distributed among all hens) were calculated. At monthly intervals, individual hens were weighed and their feathers scored using a 5-point scale on 8 body regions. Data were analyzed using a repeated measures GLM incorporating cage, tier, FSA, and age of the hen. Hens with reduced feeder space spent less time feeding (P0.001), synchronized their feeding bouts to a lesser extent (P0.001), made fewer switches at the feeder (P0.001), and shared the feeder less (P0.001). However, feather scores, BW, and BW uniformity were not affected by FSA. There was almost no aggressive behavior and little mortality. These results demonstrate that Hy-Line W-36 hens did not respond to reduced feeder space by aggressively excluding cage-mates from the feeder but instead desynchronized their feeding behavior.

Broilers are typically raised commercially in dim lighting. It has been suggested that providing brighter light intensity could improve health and provide opportunities for more normal behavioral rhythms. We examined the effects of 3 photophase light intensities (5, 50, and 200 lx) on activity patterns, immune function, and eye and leg condition of broilers (n = 753; 6 replicate pens/treatment). Broilers were reared with one of these intensities from 1 to 6 wk of age; photoperiod consisted of 16L:8D with 1 lx intensity during the scotophase. Broilers reared with 5 lx were less active (P = 0.023) during the day than 50 or 200 lx and showed less (P < 0.0001) change in activity between day and night than 50 or 200 lx. There was no difference between treatments for final BW (2.30 +/- 0.02 kg) or for most immune parameters (IgG primary and secondary responses to keyhole limpet hemocyanin, B and T lymphocyte proliferation, plasma lysozyme, haptoglobin, NO, whole blood killing of Escherichia coli and Staphylococcus aureus), but there was a trend (P = 0.072) for a greater IgM response in 50 lx (6.21 titer) than 5 lx (5.78 titer), with 200 lx (5.92 titer) intermediate. There was no effect of light intensity on back-to-front (1.13 +/- 0.01 cm) or side-to-side (1.48 +/- 0.01 cm) diameter of the eyes or on corneal radii (0.82 +/- 0.01 cm), but 5 lx (2.33 +/- 0.07 g) had heavier eyes (P = 0.002) than 50 lx (2.09 +/- 0.04 g) or 200 lx (2.11 +/- 0.04 g). There were no differences in gait score, although 200 lx broilers had more hock and footpad bruising (P = 0.038) but fewer erosions (P = 0.006) than 5 or 50 lx. Increased daylight intensity had little effect on broiler health but resulted in more pronounced behavioral rhythms.

Two experiments were conducted to assess the effect of genotype, production system, and nutrition on performance and livability of meat chickens for niche markets. Slow-growing (SG) and fast-growing genotypes (FG) were raised for 91 and 63 d, respectively, in experiment 1 (females) or 84 and 56 d, respectively, in experiment 2 (males). In each trial, SG were placed before FG to achieve a similar BW at processing. In experiment 1, each genotype was assigned to 8 pens of 20 birds each, with 4 pens within each genotype raised indoors in a conventional research facility or in a small facility with outdoor access. All birds were fed a low-nutrient diet. In experiment 2, genotype assignment to pens was as in experiment 1; however, 4 pens within each genotype were fed a low-nutrient diet or a conventional diet, and birds were raised indoors. Birds were gait-scored and commercially processed; legs were examined for tibial dyschon-droplasia lesions and scanned for bone mineral density. In experiment 1, FG gained more weight than SG (P0.05) even though they were placed later. Outdoor access increased feed intake, and feed efficiency was poorer (P0.05). Fast-growing genotypes had higher breast meat yield, whereas SG had higher wing and leg yields (P0.05). In experiment 2, the low-nutrient diet reduced (P0.05) gain of the SG; FG increased feed intake of the low-nutrient diet such that their gain was unaffected (P0.05). For FG, the low-nutrient diet resulted in a poorer (P0.05) feed efficiency. Although weight gain of the FG was maintained on the low-nutrient diet, breast yield was reduced (P0.05). Genotype affected bone health in both experiments, with SG having better gait scores and less tibial dyschondroplasia (P0.05). Outdoor access and the low-nutrient diet also resulted in better gait score (P0.05). These data indicate differences among genotypes and provide information about the efficiency and potential for alternative poultry systems.

Lighting can have important effects on the welfare of poultry, but there have been few studies of the optimal photoperiods or light intensities for broiler chickens. Birds are sensitive to light stimulation even as embryos, so both pre- and post-hatch lighting regimes could have an impact. We conducted two experiments to examine lighting effects on broiler health and behavior. In the first, broiler eggs were incubated under either complete darkness (0L:24D), complete light (24L:0D), or 12 hours of light and 12 hours of darkness (12L:12D); chicks were then raised under a 12L:12D photoperiod. In the second, chicks were raised under a 16L:8D photoperiod at one of three daytime illumination levels (dim to bright): 5 (typical commercial lighting), 50 or 200 lux. Treatment did not affect feed consumption, feed conversion, growth, mortality, or gait score. However, the eyes of both 0L:24D and 24L:0D broilers were significantly heavier at 5 lux. Activity rhythms were also affected: 24L:OD fed more during the 2 hours after the lights went on, and 5 lux were less active during the day. Broilers incubated under 0L:24D, or reared under 200 lux, were more fearful, as indicated by more intense wing flapping after being caught and inverted. In addition, 0L:24D broilers had more composite physical asymmetry, as assessed by differences in length and width of their toes and metatarsi, which is an indicator of developmental stress. These results demonstrate that providing light during incubation or brighter intensity light during rearing can have positive effects on broiler welfare without negatively affecting productivity.

Cannibalism is a major problem for commercial production of Muscovy ducks ( Cairina moschata ). Surprisingly little is known about the ontogeny of cannibalism in ducks or how to reduce/prevent the problem in a welfare-friendly way. The preventative method typically used by the industry is bill-trimming, which causes acute pain. We hypothesised that cannibalism in Muscovy ducks is a form of redirected foraging, and therefore investigated the effects of different types of environmental enrichment designed to promote foraging behaviour on general activity patterns and the ontogeny of cannibalism. Groups of 17 bill-intact female Muscovy ducklings were randomly assigned from day-old to one of three treatments (5 replicate groups/treatment): (1) water-enriched treatment (water+plastic strings, water+plastic objects+gravel, water+grain mixture, and pure water), (2) feed-enriched treatment (corn silage, alfalfa, grain mixture+gravel, and Astroturf mats+grain mixture+occasionally mealworms), and (3) control (empty troughs). Floors were covered with wood shavings, and feed and water were available ad libitum . Behaviour was recorded during daylight hours on days 7, 11, 14, and 18 of age. Water- and feed-enriched ducklings foraged significantly more than control ducklings and spent significantly less time inactive during the observations. There were no significant differences between water- and feed-enriched ducklings on these measures, or between any of the treatments for preening and locomotion. Water-enriched ducklings used their enrichments significantly more than feed-enriched ducklings. Although time spent foraging was increased in both the water- and feed-enriched ducklings, cannibalism developed in all treatments beginning at 15–17 days of age. At the end of the experiment (35 days of age), there was no significant difference among treatments in the total number of ducklings with injuries inflicted by cannibalism. Feather pecking was also observed in all three treatments, but the frequency was significantly higher at some ages in the control groups than in the water- and feed-enriched groups. Thus, our findings do not support the hypothesis that cannibalism in Muscovy ducks develops from an unfulfilled motivation for foraging.

1. We examined the effects of 4 types of environmental enrichment (foraging opportunities, structural complexity, sensory stimulation/novelty, and social companionship) on aggressive and feather pecking, feather condition, food wastage, body weight, feed conversion, and egg production in adult Japanese quail. Sex differences were examined where possible. 2. GLM analysis was used to evaluate the effects of enrichment and housing, while test-retest reliability and the stability of measures over 18 d were assessed using partial correlation. 3. Foraging enrichment reduced food wastage. 4. Body weight, feed conversion, and egg production were not affected by enrichment. Rates of aggressive and feather pecking were also not significantly affected, but these behaviours were observed very infrequently in this study. 5. Socially-housed birds had poorer feather condition, lower body weight and less efficient feed conversion than singly-housed birds. Social housing did not affect food wastage. 6. There were not sex differences in feather pecking, feather condition, food wastage, or feed conversion. 7. All measures except feather pecking were reliable over 24 h, but only feather condition and body weight were stable over 18 d. The instability f the behavioural measures over time suggest that enrichment effects may vary with age.

The purpose of this study was to determine the effect of 2 different bedding types, sand and wood shavings, on the behavior of broiler chickens. In experiment 1, 6 pens were divided down the center and bedded half with sand and half with wood shavings. Male broilers (10/pen) were observed by scan sampling at 5- or 12-min intervals throughout the 6-wk growth period during the morning (between 0800 to 0900 h), afternoon (1200 to 1500 h), and night (2300 to 0600 h). There was a significant behavior x substrate x week interaction during the day (P < 0.0001) and at night (P < 0.0002). Drinking, dustbathing, preening, and sitting increased in frequency on the sand side but decreased on the wood shavings side during the day, as did resting at night. In general, broilers performed a greater proportion of their total behavioral time budget on the sand (P < 0.0001) as they aged. Broilers used the divider between the 2 bedding types to perch; perching behavior peaked during wk 4. In experiment 2, male broilers were housed in 8 pens (50 birds/pen) bedded only in sand or wood shavings. Bedding type had no effect on behavioral time budgets (P = 0.8946), although there were age-related changes in behavior on both bedding types. These results indicate that when given a choice, broilers increasingly performed many of their behaviors on sand, but if only one bedding type was provided they performed those behaviors with similar frequency on sand or wood shavings.

1: Biological Response to Stress: Implications for Animal Welfare, G P Moberg, University of California, USA 2: Some Issues in the Interpretation of Behavioural Responses to Stress, J Rushen, Dairy and Swine Research and Development Centre, Agriculture and Agri-food Canada, Canada 3: Neoroendocrine Responses to Stress, R L Matteri, J A Carroll and C J Dyer, University of Missouri, USA 4: The Metabolic Consequences of Stress: Targets for Stress and Priority of Nutrient Use, T H Elsasser et al., USDA, Agricultural Research Service, USA 5: Immune System Response to Stress, F Blecha, Kansas State University, USA 6: Hands-on and Hands-off Measurement of Stress, C J Cook et al., Horticultural and Food Research Institute of New Zealand, New Zealand 7: Accumulation and Long-Term Effects of Stress in Fish, C B Schreck, Oregon State University, USA 8: Chronic Intermittent Stress: A Model for the Study of Long Term Stressors, J Ladewig, The Royal Veterinary and Agricultural University, Denmark 9: Quantifying Some Responses to Pain as a Stressor, D J Mellor, Massey University, New Zealand, C J Cook and K J Stafford, Horticultural and Food Research Institute of New Zealand, New Zealand 10: Multiple Factors Controlling Behaviour: Implications for Stress and Welfare, F Toates, The Open University, Milton Keynes, UK 11: Chronic Social Stress: Studies in Nonhuman Primates, S P Mendoza, J P Capitanio and W A Mason, University of California, USA 12: Consequences of Stress During Development, D C Lay Jr., Iowa State University, USA 13: Early Developmental Influences of Experience on Behaviour, Temperament, and Stress, W A Mason, University of California, USA 14: Genetic Selection to Reduce Stress in Animals, T G Pottinger, NERC Institute of Freshwater Ecology, Windermere Laboratory, Cumbria, UK 15: Human-Animal Interactions and Animal Stress, P H Hemsworth and J L Barnett, Agriculture Victoria, Australia 16: Alleviating Stress in Zoo Animals with Environmental Enrichment, K Carlstead, National Zoological Park, Washington, USA and D Shepherdson, Oregon Zoo, USA 17: Understanding the Role of Stress in Animal Welfare: Practical Considerations, T L Wolfle, formerly of the Institute for Laboratory Animal Research, National Research Council, National Academy of Sciences, USA

1. Experiments were conducted to determine whether different handling methods and crating periods differentially affect plasma corticosterone (CS) concentrations in 6 to 7-week-old broilers. 2. Broilers were subjected to 1 of 3 handling methods for 2 min: (i) 3 birds held in an inverted position in one hand (multiple inverted, MI), (ii) 1 bird held in an inverted position (single inverted, SI), or (iii) upright handling (U), which consisted of holding a bird gently with both hands in an upright position. 3. In experiment 1 birds were returned to their respective pens after handling and in experiment 2 they were crated for up to 4 h after the imposition of handling. In experiment 2 food deprived (FD) and fully fed (FF) uncrated birds were also sampled as controls. Blood samples were collected immediately after handling and at 1-h intervals after handling or handling and crating. 4. In experiment 1, MI and SI birds had higher CS concentrations than U birds. 5. In experiment 2, there were no significant differences in CS concentrations of crated birds despite the different handling treatments. FD birds had higher mean CS concentrations than FF birds, although not as high as those of crated birds. CS concentrations peaked at 3 h after crating. Birds showed predominantly resting behaviour after crating. 6. These results suggest that handling stress can be reduced in broilers by the use of upright handling. However, the methods of handling is not important in influencing CS concentrations if the birds are crated after handling, either because crating is a more potent stressor than handling or due to stressor additivity.

Broiler breeders display high levels of aggressive activity as a result of feed restriction. The objective of this study was to determine if aggressive activity in developing and mature broiler breeder males is influenced by increased dietary L-tryptophan (Trp). Broiler breeder males were raised using a skip-a-day feed restriction regimen. In Experiment 1, three levels of dietary Trp, .19 (control), .75, and 1.5%, were fed from the start of feed restriction at 4 wk of age and throughout development. All occurrences of aggressive behavior were recorded during three 20-min observation sessions per week on mornings on which feed was not delivered through Week 20. The Trp significantly decreased (P less than .05) aggressive pecking in birds fed supplemental Trp as compared to controls. No differences in threatening behavior were found. In the second part of Experiment 1, the effect of continued Trp supplementation on mature flocks of male broiler breeders and time-of-day effects on aggression were investigated. A depressing effect of supplemental Trp on pecking and threatening was observed. Maximum aggressive activity in all treatment groups occurred on mornings when feed was delivered. In Experiment 2, four levels of Trp, .19 (control), .38, .75, and 1.5%, were fed to developing birds as in Experiment 1. Birds fed supplemental Trp pecked less (P less than .05) than controls and .38% Trp was as effective in decreasing pecking as was 1.5%. It was concluded that increased levels of dietary Trp decrease aggression in both developing and mature, socially stable flocks of broiler breeder males.

Commercial meat-type birds are commonly reared in large groups at high population densities, and may also be severely feed-restricted in breeding flocks. Although these factors are all recognized to affect aggressive behavior in domestic animals, there have been few studies of aggression in meat-type birds. The present experiments were designed firstly to investigate whether selection for growth has modulated the development of aggressive behavior in male broiler chicks, and secondly to determine the influence of feed restriction on aggression. In the first experiment, broiler males were compared with males from a brown egg-laying strain and a white egg-laying strain. No significant differences were found between brown and white egg-type males in the frequency of pecking and threatening, with both groups showing a rise in these behaviors as expected until 8 weeks of age. Pecking and threatening in broilers, however, remained extremely low throughout this period. Sparring did not differ among the three strains. In the second and third experiments, broilers fed either ad libitum (AD) or placed on skip-a-day feed restriction (SK) were compared. SK sparred less but were more aggressive than AD until 15 weeks of age. Aggressive activity in SK was particularly elevated on feed-off mornings, and decreased to its lowest levels after SK were placed on full feed for only 4 days. Selection for growth thus appears to have resulted in a decrease in aggressiveness, regardless of actual body weight, at least when food is provided ad libitum. It is concluded that problems associated with aggressive behavior are likely to be of little significance in commercial broiler flocks, which are marketed at 7–8 weeks of age, but are of importance in breeder flocks maintained on feed-restricted diets.