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The northern fowl mite (Ornithonyssus sylviarum) is a key pest for caged laying hens. High infestation levels can lead to anemia, reduced production, and mortality. Although the mites cause skin irritation and thus likely affect resting behavior, the nocturnal behavior of infested chickens has not yet been studied. We investigated the impact of mite infestation on nighttime behavior of 16 beak-trimmed White Leghorn hens. The hens were housed individually in wire cages. They were experimentally inoculated with approximately 35 mites at 25 weeks of age and observed for the behaviors dozing, sleeping, preening and being active. Continuous observations were made from video recordings taken from 22:00 h until 06:00 h for two consecutive nights at pre-infestation week 0 and post-infestation weeks 3, 5 and 7. Mite infestation levels were measured weekly on an 8-point scale (0 (no mites) to 7 (≥10,000 mites per hen)). For statistical analyses with linear mixed models, mite infestation levels were categorized as score 0 (no mites), 3–4 (51–500), 5 (501–1000) and 6–7 (>1000). Higher levels of mite infestation were associated with hens spending less time dozing (P < 0.001) and more time preening (P < 0.001) and being active (P = 0.012). Dozing decreased from 90% of the observed time for mite score 0 to 76% for score 6–7. Preening increased from 2% (score 0) to 9% (6–7) and time spent being active increased from 1% (0) to 7% (6–7). Mite infestation increased the number of uninterrupted bouts of all behaviors (P ≤ 0.020), especially dozing and preening (P < 0.001), suggesting restlessness in the mite-infested hens due to irritation and itching. The mite-infested hens’ increased nocturnal activity, including preening, as well as the fragmentation of behavioral activities together with decreased dozing, indicate disturbed resting behavior and suggest a reduction in the welfare of mite-infested hens.

Understanding the affiliative social relationships, or bonds, between zoo elephants has implications for both their welfare and management, yet there is limited work assessing and describing these bonds. Consequently, there is a need for the development of a reliable assessment tool. We used multiple metrics of proximity and tactile contact, as well as keeper surveys, to assess the social bond strength of 41 elephant dyads from 22 different zoos. Survey descriptions of social bond strength were based on previous research and included proximity and separation-reunion behaviors between individuals in a dyad. Approximately half of the elephant dyads in our study were rated as having a “strong” or “strongest” bond by keepers, who showed excellent agreement in their ratings of elephant bond strength (ICC(1,k) = 0.82). Elephant dyads that spent more time in proximity (within two elephant body lengths), and those that were more consistent in this behavior across time had an increased predicted probability of being rated as having a “strong or strongest bond” by keepers (p

Chickens provided with outdoor access often do not fully use the range area. Natural cover, such as trees, can provide shelter and increase range use, but may not be practical for use in all free-range operations. A study was conducted to determine whether constructed enrichments that simulate natural structures increase range use and impact behavior of meat chickens. Slow-growing Delaware chickens were raised in floor pens (17 birds/pen) in a naturally ventilated house, with a pophole in each pen that allowed daily access to a vegetation-covered outdoor area. Feed and water were provided inside and outside. Birds were randomly assigned to one of 2 treatments: no range enrichment (control; NON) or range enrichment (ENR), which had roosts made of plastic pipe or screened shelters placed 7.6 m and 22.9 m from the house and overhead shade panels at 15.2 m. There were 4 replications. The numbers of birds inside and in the 4 quadrants of the range were counted in 7-min intervals 3 times daily (0900 h, 1300 h, and 1600 h) for 3 consecutive d when the birds were 7 and 10 wk of age; the numbers of birds performing various behaviors also were counted. On average, only 12.9% of birds used the range at any given time. The behavior of the birds was strongly affected by location (inside vs. outside), with birds mainly foraging and walking while outside and feeding, standing, and sitting while inside. Time of d impacted the number of birds that ranged (P ≤ 0.0001), with fewest birds outside during mid-day. Overall, birds using the range were most often (71%) observed in the quadrant nearest the house (zero to 7.6 m). However, in the ENR treatment, more birds (13%; P ≤ 0.0001) were observed in the farthest 2 quadrants (15.2 to 30.5 m from the house) than in the NON treatment (6%). This indicates that adding constructed enrichments to the range encouraged meat chickens to use it more fully.

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.

The strategies that animals use to obtain valuable resources are affected by resource quality and availability (e.g. spatial distribution), population dynamics (e.g. competitor-to-resource ratio) and individual characteristics (e.g. competitive ability). Theoretical papers and field observations suggest that aggressive resource competition, particularly by individuals with high competitive ability, increases as the competitor-to-resource ratio increases. On the other hand, individuals with low competitive ability should adopt a scramble competitive strategy, for example by expanding their home range or utilizing resources at suboptimal times. We tested these theoretical predictions in male house mice, Mus musculus domesticus, by experimentally manipulating the distribution of a desirable resource, a running wheel. Four male mice were exposed to three treatments (zero, one or four running wheels present) using a repeated measures design. We found that aggression increased as the competitor-to-resource ratio increased. In addition, mice with high competitive ability had species-typical nocturnally biased activity and running wheel use patterns, while mice with low competitive ability had more diurnally biased activity and running wheel use patterns. Our results show that aggression encourages less competitive mice to adopt a scramble competitive strategy through temporal partitioning and provides empirical evidence for the predictions of resource defence theory.

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.

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.

The egg industry is moving away from the use of conventional cages to enriched cage and noncage laying hen housing systems because of animal welfare concerns. In this study, the prevalence and severity of lesions in noncage laying hens from commercial farms in two of the largest egg-producing states, California and Iowa, were evaluated by postmortem examination. Hens that died or were culled were collected during early, mid, and late stages of the laying cycle from 16 houses on three farms. Of the 25 gross lesions identified for study, 22 were observed, with an average of four lesions per hen. Vent cannibalism, reduced feather cover, keel bone deformation, and beak abnormalities were the most frequent lesions, observed in ≥40% of hens. Other common lesions were cloacal prolapse (30.5%), footpad dermatitis (24.3%), and septicemia (23.1%). Beak abnormality and enteric disease had the highest proportion of severe lesions. Pearson chi-square analysis revealed a number of stage-of-lay effects (P ≤ 0.05), some of which differed by state. For both states combined, the lesions observed more frequently during early lay were beak abnormalities, northern fowl mite infestation, and cage layer fatigue, whereas during mid lay, they were poor feather cover, vent cannibalism, footpad dermatitis, keel bone deformation, respiratory disease and roundworms. Feather pecking and cloacal prolapse were most common during late lay. Although differences in hen genetics, farm management practices, and environmental factors could all have affected the results of this study, the information provides a better understanding of hen health in noncage housing systems and could help to identify potential interventions to reduce hen welfare problems.

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

Pre-clinical investigation of human CNS disorders relies heavily on mouse models. However these show low predictive validity for translational success to humans, partly due to the extensive use of rapid, high-throughput behavioral assays. Improved assays to monitor rodent behavior over longer time scales in a variety of contexts while still maintaining the efficiency of data collection associated with high-throughput assays are needed. We developed an apparatus that uses radio frequency identification device (RFID) technology to facilitate long-term automated monitoring of the behavior of mice in socially or structurally complex cage environments. Mice that were individually marked and implanted with transponders were placed in pairs in the apparatus, and their locations continuously tracked for 24 h. Video observation was used to validate the RFID readings. The apparatus and its associated software accurately tracked the locations of all mice, yielding information about each mouse's location over time, its diel activity patterns, and the amount of time it was in the same location as the other mouse in the pair. The information that can be efficiently collected in this apparatus has a variety of applications for pre-clinical research on human CNS disorders, for example major depressive disorder and autism spectrum disorder, in that it can be used to quantify validated endophenotypes or biomarkers of these disorders using rodent models. While the specific configuration of the apparatus described here was designed to answer particular experimental questions, it can be modified in various ways to accommodate different experimental designs.

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.

The northern fowl mite (NFM), Ornithonyssus sylviarum, is the most common ectoparasite of laying hens in North America. Infestation can cause a reduction in egg production, egg weights, and feed conversion efficiency. However, there is a lack of information on the effects of NFM on hen physiology, physical condition, and egg quality. Singly caged beak-trimmed White Leghorn hens (N = 32) were infested with mites at 25 wk of age. The condition of each hen was assessed at wk 0 (infestation) and wk 5 and 7 post-infestation to determine comb temperatures and feather, skin, and comb condition. Heterophil-lymphocyte (H/L) ratios and body weight (BW) were evaluated at wk 0 and wk 1, 3, 5, and 7 post-infestation. Egg weight, egg specific gravity, yolk color, Haugh unit (HU), and eggshell thickness were determined prior to infestation (wk -1) and at 1, 3, 5, and 7 wk post-infestation. The H/L ratio (P < 0.0001), HU (P < 0.0001), and egg specific gravity (P = 0.001) were lowest, and the egg yolk color was lightest (P = 0.087) at wk 5, the peak of infestation. At wk 5 and 7, more than 65% of the hens had red skin and more than 75% had scabs on the vent; in addition more than 84% had grey-black vent feathers. There were no effects of infestation on comb color, comb temperature, feather cover, BW, or eggshell thickness. It was concluded that infestation with NFM has negative effects on interior egg quality and hen integument. A decrease in H/L ratio was also observed at the peak of infestation. However, the effects of NFM on the immune system are unclear, and H/L ratio might not be a good stress measure in hens highly infested with NFM.

Stereotypic behavior is an important indicator of compromised welfare. Zoo elephants are documented to perform stereotypic behavior, but the factors that contribute to performance have not been systematically assessed. We collected behavioral data on 89 elephants (47 African [Loxodonta africana], 42 Asian [Elephas maximus]) at 39 North American zoos during the summer and winter. Elephants were videoed for a median of 12 daytime hours per season. A subset of 32 elephants (19 African, 13 Asian) was also observed live for a median of 10.5 nighttime hours. Percentages of visible behavior scans were calculated from five minute instantaneous samples. Stereotypic behavior was the second most commonly performed behavior (after feeding), making up 15.5% of observations during the daytime and 24.8% at nighttime. Negative binomial regression models fitted with generalized estimating equations were used to determine which social, housing, management, life history, and demographic variables were associated with daytime and nighttime stereotypic behavior rates. Species was a significant risk factor in both models, with Asian elephants at greater risk (daytime: p

We evaluated 255 African (Loxodonta africana) and Asian (Elephas maximus) elephants living in 68 North American zoos over one year to quantify housing and social variables. All parameters were quantified for the both the day and the night and comparisons were made across these time periods as well as by species and sex. To assess housing, we evaluated not only total exhibit size, but also individual animals’ experiences based on the time they spent in the unique environments into which the exhibits were subdivided. Variables developed to assess housing included measurements of area as a function of time (Total Space Experience), environment type (Indoor, Outdoor, In/Out Choice) and time spent on hard and soft flooring. Over the year, Total Space Experience values ranged from 1,273 square feet to 169,692 square feet, with Day values significantly greater than Night values (p

This study quantified social life events hypothesized to affect the welfare of zoo African and Asian elephants, focusing on animals that were part of a large multi-disciplinary, multi-institutional elephant welfare study in North America. Age was calculated based on recorded birth dates and an age-based account of life event data for each elephant was compiled. These event histories included facility transfers, births and deaths of offspring, and births and deaths of non-offspring herd mates. Each event was evaluated as a total number of events per elephant, lifetime rate of event exposure, and age at first event exposure. These were then compared across three categories: species (African vs. Asian); sex (male vs. female); and origin (imported vs. captive-born). Mean age distributions differed (p

In commercial production facilities, ducks are often bill-trimmed to prevent feather pecking and cannibalism. Beak-trimming of chickens and turkeys has been criticized because of its potential to cause acute and chronic pain, but little is known about the effects of bill-trimming on the welfare of ducks. We conducted a study to determine the effects of a commercial bill-trimming method, cutting without cautery, on the behavior and bill morphopathology of ducks. Muscovy ducks were housed in six pens each containing 16 ducks (eight males and eight females). Three pens of ducks were trimmed (TRIM) using scissors at 20 days post-hatch, while ducks in the remaining three pens were sham-trimmed (NOTRIM). The average length removed from the upper bill was 0.51cm, or 21.1% of the bill length from nares to tip. The behavior of all ducks was recorded during the first week post-trim using scan sampling. In addition, two ducks/sex/pen were randomly selected as focal birds, and observed using 15-min focal samples during the morning (0900–1100) and afternoon (1200–1500) for 7 weeks post-trim. Ducks were weighed weekly. Behavioral and body weight data were analyzed using the General Linear Model. At 12 weeks of age, the male focal ducks were killed and their bills were then collected and subjected to gross and morphopathological analysis. In the days immediately post-trim, TRIM ducks spent significantly less ( p p =0.0064) than NOTRIM, but there was no treatment difference in weights by 2 weeks post-trim. By 6 weeks post-trim the upper bill of TRIM was only 11.9% shorter than the lower bill. There was evidence of feather pecking in the TRIM pens, but feather pecking and skin damage were more extensive in the NOTRIM pens. The TRIM bill stumps were covered with epithelium, lacked blood vessels and showed evidence of scarring, but there were no neuromas. These results are consistent with this bill-trimming method causing acute, but not chronic, pain in Muscovy ducks.

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

If fearfulness is stable, consistent and trait-like, then valid measures of fearfulness should be stable, consistent and independent of influences unrelated to fear. We assessed the validity of six fear measures using Japanese quail, Coturnix coturnix japonica, a common species in fear research. Measures were made during emergence, novel object, novel food and predator surprise tests. These were considered to have internal validity if they were stable over 18 days, when we controlled for nonexperimental variables including season of testing and cage location. We determined convergent and discriminant validity by factor analysis of fear measures plus measures of sociality, activity level and repetitive behaviour. Fear measures with good convergent validity showed agreement in their factor loadings. Those with good discriminant validity loaded on to different factors from nonfear measures. Most of the fear measures examined were moderately stable over time, but only half had good discriminant validity. Convergence was good among measures from the same test but poor across tests. Measures from each fear test loaded separately. Overall, flight distance and freezing duration in the predator surprise test and amount eaten in the novel food test showed the best internal, convergent and discriminant validity. When we considered only these three measures, convergence remained higher among measures from the same test than from different tests. Fearfulness thus appeared somewhat unstable over time and inconsistent across situations, which, if true across species, greatly limits the utility of fear tests.

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

Tests of animal fearfulness are being used in a broad range of basic and applied scientific fields. However, rigorous assessment of the test–retest reliability of these tests is relatively uncommon. The importance of such assessment is illustrated by this study of the responses of Japanese quail during four tests of fearfulness. Forty-six adult quail were subjected to an emergence test, novel object test, novel food test, and predator surprise test on two consecutive days to assess test–retest reliability. Multiple behavioural measures were made during each test. One test was performed per day. There were discrepancies in the reliabilities of the various measures made within each test. For example, latency to extend the head into the emergence arena was poorly correlated on two consecutive days (partial r =.19, n =46, P =.29), but the number of times the birds extended their heads into the arena was much more reliable (partial r =.73, n =46, P r =.47, n =46, P r =.81, n =46, P r =.19, Pearson's r =.52). Finally, the statistically significant but small correlation coefficients for many measures in this study and other published fear studies, many less than .4, indicate that some common behavioural measures of fearfulness are not always reliable.

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.

Birds are used for a variety of teaching and research purposes. While domesticated species like chickens, turkeys, and quail are probably the most frequently used birds, a range of species that vary widely in terms of their behavior and their husbandry and care needs may be kept. We provide an overview of some aspects of the anatomy, physiology, and behavior of birds, and address general aspects of avian care in the laboratory setting. These include housing, environment, nutrition, environmental enrichment, handling, transport, special management practices (sexing, identification, incubation, insemination, chick rearing), field studies, amelioration of pain and distress, and euthanasia. While there is a great deal of information about these topics available for poultry, there is much less for captive wild species, so individuals responsible for their care will need to consult relevant literature and experts to ensure that the needs of those species are met in the laboratory setting.

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.

Psittacines are generally considered to possess cognitive abilities comparable to those of primates. Most psittacine research has evaluated performance on standardized complex cognition tasks, but studies of basic cognitive processes are limited. We tested orange-winged Amazon parrots (Amazona amazonica) on a spatial foraging assessment, the Hamilton search task. This task is a standardized test used in human and non-human primate studies. It has multiple phases, which require trial and error learning, learning set breaking, and spatial memory. We investigated search strategies used to complete the task, cognitive flexibility, and long-term memory for the task. We also assessed the effects of individual strength of motor lateralization (foot preference) and sex on task performance. Almost all (92 %) of the parrots acquired the task. All had significant foot preferences, with 69 % preferring their left foot, and showed side preferences contralateral to their preferred limb during location selection. The parrots were able to alter their search strategies when reward contingencies changed, demonstrating cognitive flexibility. They were also able to remember the task over a 6-month period. Lateralization had a significant influence on learning set acquisition but no effect on cognitive flexibility. There were no sex differences. To our knowledge, this is the first cognitive study using this particular species and one of the few studies of cognitive abilities in any Neotropical parrot species.

The effects of age, sex and previous experience on colour avoidance in northern bobwhites, Colinus virginianus , were evaluated. First, unlearned colour preferences were determined by measuring pecking by 52 1-day-old bobwhite chicks at pinheads of four colours. The number of first pecks and the total number of pecks varied significantly among colours ( P =0·011 and P green>yellow>red. There were no clear sex differences in pecking preference. A second experiment used a two-cup avoidance test to evaluate the effects of sex and previous experience on avoidance of coloured grain by juvenile bobwhite. Forty 11-week-old birds were pre-exposed for 7 days to either multi-coloured or undyed food, and then tested for 5 days for avoidance of red or blue food. Red food was avoided relative to undyed food (preference ratio=0·426, P =0·004), whereas blue food was not avoided. Sex of bird, pre-exposure to coloured food, and day of test had no significant effect on colour avoidance. Finally, 26 of the same birds were retested at the age of 31 weeks for avoidance of blue and red food. Results indicated no change in colour avoidance with age. Although these experiments failed to replicate a sex difference in colour avoidance that we found in a previous study, they did demonstrate that bobwhites show an unlearned aversion to red which is persistent and resistant to extinction. Because red is a common warning colour in insects, this aversion may be an adaptation for avoiding aposematically coloured prey.

The management of African (Loxodonta africana) and Asian (Elephas maximus) elephants in zoos involves a range of practices including feeding, exercise, training, and environmental enrichment. These practices are necessary to meet the elephants’ nutritional, healthcare, and husbandry needs. However, these practices are not standardized, resulting in likely variation among zoos as well as differences in the way they are applied to individual elephants within a zoo. To characterize elephant management in North America, we collected survey data from zoos accredited by the Association of Zoos and Aquariums, developed 26 variables, generated population level descriptive statistics, and analyzed them to identify differences attributable to sex and species. Sixty-seven zoos submitted surveys describing the management of 224 elephants and the training experiences of 227 elephants. Asian elephants spent more time managed (defined as interacting directly with staff) than Africans (mean time managed: Asians = 56.9%; Africans = 48.6%; p

The risk of accidental poisoning of birds may be reduced by adding an aversive-tasting chemical to granular pesticides. The efficacy of eight taste repellents in deterring consumption was therefore evaluated in a game species, the northern bobwhite (Colinus virginianus). Avoidance was measured using a two-cup preference test in which treated feeds were paired with untreated feeds in one experiment, and against other treated feeds in another experiment. All repellents tested were significantly avoided without evidence of habituation during the 5-d test period. The most effective repellents were d-pulegone and quinine hydrochloride. Methyl anthranilate, 2-heptanone, and lithium chloride also performed reasonably well, whereas sucrose octaacetate and cinnamaldehyde performed relatively poorly. The d-pulegone was further evaluated using a one-cup test with treated clay granules. The effects of adding d-pulegone and/or a red dye (erythrosine) were evaluated with a two-way factorial design. Addition of d-pulegone strongly reduced consumption of granules (p

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, leading to disrupted feeding, inadequate nutrient intake, stress, and reduced productivity. The effects of feeder space allocation (FSA) on physiology and productivity were evaluated in beak-trimmed Hy-Line W-36 hens (n=480). They were obtained at 16.5 wk of age and housed on 4 tiers of shallow conventional cages. Five pullets/cage were housed at a stocking density of 434 cm2/hen and a feeder space of 12.2 cm/hen. After 1.5 wk of acclimation, baseline measurements were taken for feed utilization, bone mineralization, and heterophil:lymphocyte ratios. At 20 wk of age, pullets were given 5.8, 7.1, 8.4, 9.7, 10.9, or 12.2 cm of feeder space/bird (16 cages/treatment). Physiological and production measures were calculated monthly or twice a month for 12 mo. The heart, spleen, and right adrenal gland were collected from each hen at the end of the study. Data were analyzed using a repeated measures GLM incorporating cage, tier, FSA, and hen age. There were no effects of FSA on total egg production, bone mineral density, bone mineral content, heterophil:lymphocyte ratios, or organ weights. Hens with reduced FSA utilized more feed (P0.001), had poorer feed conversion (P0.001), and laid eggs with slightly thicker and heavier shells (P0.001). There were effects of FSA on total egg weight (P0.001) and hen-day egg production (P0.001), but they were of low magnitude and not linear (P0.05). Because BW was similar among FSA treatments, the results suggest that reduced feeder space did not limit feed intake. In addition, reduced FSA did not lower bone mineralization or cause physiological stress in W-36 hens housed in shallow cages, suggesting that it did not impair hen welfare. However, it did result in poorer feed efficiency, possibly related to greater feed wastage, predictive of an adverse economic effect from reducing feeder space.

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.

The corticosterone response of immature broiler breeder males to feed restriction and the administration of increased levels of dietary Trp was investigated. Corticosterone levels were significantly (P less than .01) higher in birds placed on a skip-a-day (SD) feed restriction regimen from 4 to 15 wk of age than in birds fed an ad libitum intake. Elevated levels in SD birds persisted for the duration of the study. Levels were also higher in SD birds on those days on which feed was withheld (FEED-OFF) than on those days on which feed was delivered (FEED-ON). The SD males consuming a diet containing 1.5% Trp showed a change in the pattern of hormone secretion as compared with SD control birds (.19% Trp), with corticosterone levels increasing on the FEED-ON days and decreasing on the FEED-OFF days. It is concluded that SD feed restriction causes a persistent elevation of plasma corticosterone in broiler breeders. The secretory pattern of corticosterone can be modulated by increasing the Trp content of the diet, possibly as a result of reciprocal interactions between the serotonergic system and the hypothalamic-pituitary-adrenal axis.

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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.

Pekin ducks are often bill-trimmed to prevent feather pecking and cannibalism, but this practice has been criticized because of the resulting potential for acute and chronic pain. The goal of this experiment was to compare 2 different bill-trimming methods, hot blade trimming with cautery (TRIM) and cautery only (tip-searing; SEAR), on the behavior, bill morphology, and weight gain of Pekin ducks. Ducklings (n = 192, 96 per sex) were trimmed at the hatchery and assigned to 12 floor pens (3.66 x0.91 m) by treatment. Behavior was evaluated by scan sampling, and plumage condition was scored using a 0 to 3 scoring system. Thirty-six ducks were randomly euthanized at 3 and 6 wk of age, and their bills were collected for examination. Following fixation and decalcification, the bills were embedded in paraffin wax and sectioned longitudinally. Alternate sections were stained with hematoxylin and eosin and Masson's trichrome for the connective tissues, and with Bielschowsky's silver impregnation, Bodian's staining, and Holmes' staining for the nerve fibers. Trimmed ducks engaged in fewer bill-related behaviors and rested more than untrimmed ducks (NOTRIM) during the first 2 wk posttrim. Ducks in the SEAR and NOTRIM groups showed similar patterns of weight gain, but those in the TRIM group had a lower rate of gain than ducks in the SEAR group during the first week posttrim and had a lower rate of gain than those in the NOTRIM group for 2 wk posttrim. Feather scores of ducks in the NOTRIM group were significantly worse than those in the TRIM or SEAR group by 18 d, and scores continued to deteriorate at a greater rate than those of trimmed ducks throughout the study. Both trimming methods caused connective tissue proliferation in the bill stumps, but the TRIM method caused thicker scar tissue than the SEAR method. No neuromas were found with either trimming method, but there were more nerve fibers in bill stumps of the SEAR ducks than the TRIM ducks. These results suggest that acute pain is associated with both trimming methods, but that SEAR may be a preferable method, causing less check in weight gain and fewer bill morphological changes while still being effective in minimizing feather pecking damage.

Parrots are popular companion animals, but are frequently relinquished because of behavioral problems, including abnormal repetitive behaviors like feather damaging behavior and stereotypy. In addition to contributing to pet relinquishment, these behaviors are important as potential indicators of diminished psychological well-being. While abnormal behaviors are common in captive animals, their presence and/or severity varies between animals of the same species that are experiencing the same environmental conditions. Personality differences could contribute to this observed individual variation, as they are known risk factors for stress sensitivity and affective disorders in humans. The goal of this study was to assess the relationship between personality and the development and severity of abnormal behaviors in captive-bred orange-winged Amazon parrots (Amazona amazonica). We monitored between-individual behavioral differences in enrichment-reared parrots of known personality types before, during, and after enrichment deprivation. We predicted that parrots with higher scores for neurotic-like personality traits would be more susceptible to enrichment deprivation and develop more abnormal behaviors. Our results partially supported this hypothesis, but also showed that distinct personality dimensions were related to different forms of abnormal behavior. While neuroticism-like traits were linked to feather damaging behavior, extraversion-like traits were negatively related to stereotypic behavior. More extraverted birds showed resiliency to environmental stress, developing fewer stereotypies during enrichment deprivation and showing lower levels of these behaviors following re-enrichment. Our data, together with the results of the few studies conducted on other species, suggest that, as in humans, certain personality types render individual animals more susceptible or resilient to environmental stress. Further, this susceptibility/resiliency can have a long-term effect on behavior, as evidenced by behavioral changes that persisted despite re-enrichment. Ours is the first study evaluating the relationship between personality dimensions, environment, and abnormal behaviors in an avian species.