The relationship between pre-laying activity and corticosterone concentrations, and the interpretation for laying hen welfare (original) (raw)
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Italian Journal of Animal Science, 2005
Adrenocortical and thyroidal hormones are physiological indicators of various forms of stress in the fowl. In order to establish possible variations in corticosterone levels, blood samples were collected from ISA Brown hens reared in three different housing systems (cage, floor and organic way). Results showed that corticosterone concentrations were highest in caged hens, intermediate in organic reared hens and lowest in floor reared hens. It could be assumed that in the last one system birds have an adequate space in controlled environment that permits them to satisfy, though partially, their behavioural needs without the presence of different chronic stress factors acting in the other systems.
Physiology & Behavior, 2009
The aim of the present study was to investigate the effect of brooding and group selection for low mortality on post-stress corticosterone and peripheral serotonin in laying hens. Birds in the experiment originated from the same population and were either group-selected for low mortality (low mortality line) or randomly selected (control line) for two generations. Twelve groups of seven birds from each line were used. Within each line, six groups were brooded by a foster mother and six groups were non-brooded. At 33 weeks of age, birds (n = 42/treatment) were manually restrained for 5 min, during which their behavioral response (number of struggles) was studied. Fifteen minutes after the start of the manual restraint, blood samples were drawn for assessment of plasma corticosterone and whole blood serotonin (5-HT) concentration. In the low mortality line, 80% of the birds struggled and vocalized vs. 72% in the control line (non significant). Birds from the control line had a higher plasma corticosterone concentration after manual restraint than birds from the low mortality line (7.7 vs. 6.0 nmol ml − 1 ). Furthermore, birds from the control line that were reared without a mother had a lower whole-blood 5-HT concentration than birds from the other treatments (45 vs. 48 nmol ml − 1 ). These results indicate that both brooding and selection for low mortality affect poststress corticosterone and peripheral serotonin concentration, which may result in a reduced propensity to develop feather pecking.
Poultry Science, 2009
Measurements of the heterophil:lymphocyte (H/L) ratio (invasive technique) and corticosterone in yolk and albumen (noninvasive techniques) were used to measure stress in 3 commercial laying strains, Lohmann White (LW), H&N White (HN), Lohmann Brown (LB), and a noncommercial cross (CR) between Rhode Island Red (male) and Barred Plymouth Rock (female), kept in conventional cages or floor pens. All chicks were reared in their respective environments, and 450 and 432 pullets were placed at 18 and 7 wk of age in cages and floor pens, respectively. Blood from 12 hens per strain was taken at 19, 35, and 45 wk of age in each housing system. A total of 100 heterophils and lymphocytes were counted and their ratio (H/L ratio) was calculated. Corticosterone was measured in yolk and albumen from 12 hens per strain in each housing system at 22 and 45 wk of age. The H/L ratio was within the normal range. The interaction between en-vironment and strain for the H/L ratio showed that in both environments, LB and CR hens had a higher H/L ratio than LW and HN layers. In cages, there were significant differences in H/L ratios between LW and HN hens that were likely due to genetic differences. The LW hens had significantly lower corticosterone concentrations in yolk than LB hens. In cages but not floor pens, yolk corticosterone concentrations at wk 22 were significantly higher than at wk 45. In floor pens but not cages, albumen corticosterone at wk 22 was higher than at wk 45. The H/L ratios suggest that none of the hens were unduly stressed, and corticosterone levels in yolk and albumen support the suggestion that hens adapted to their environments with age. Although measurement of yolk corticosterone and the H/L ratio may be comparable, the measurement of corticosterone level in the albumen may differ because it is secreted over a short time.
Behavioural and physiological responses of laying hens to humans
Animal Production Science, 2010
Human interactions, particularly negative ones, affect the behaviour and physiology of laying hens, with possible implications for bird productivity and welfare. The present experiment investigated the effects of handling on the behaviour and plasma corticosterone concentrations of laying hens. A 2 × 2 × 3 factorial design was used to study the following three main effects: human contact during rearing [an additional 12 min of human contact per day (AC) or no additional contact (MC) during rearing]; handling quality in adulthood [brief daily exposure to positive (+ve) or negative (–ve) visual contact with a human]; and handling proximity in adulthood [handling-quality treatment (+ve or –ve) imposed at the following three distances from the birds: Near, 0–45 cm; Middle, 45–75 cm, or Far, 75–105 cm]. AC during rearing resulted in reduced avoidance behaviour of humans during adulthood, whereas handling imposed at the Far level resulted in greater avoidance behaviour than did handling a...
British Poultry Science, 2009
1. Previous studies have shown that more yolk corticosterone is found in the eggs of random bred Japanese quail hens implanted with corticosterone during egg formation; both unstressed and stressed quail hens selected for exaggerated (high stress) rather than reduced (low stress) plasma corticosterone response to brief restraint deposit more corticosterone into their egg yolks. The length of egg incubation is also known to be shorter in eggs laid by high than low stress hens. 2. Here we investigated the interactive effects of quail stress line (low vs. high stress) with maternal corticosterone treatment (empty implant controls vs. corticosterone-implants) during egg formation on length of egg incubation. 3. Mean (AESEM) length of egg incubation for high stress control eggs (397Á3 AE 0Á4 h) was similarly shorter (by about 4.5 h) than that found for low stress control eggs (392Á8 AE 0Á2 h). In addition, on average, the incubation length of eggs laid by corticosterone-implanted hens (392Á9 AE 0Á5 h) was nearly 3 h shorter than that found for eggs laid by control hens (395Á8 AE 0Á2 h) regardless of stress line. 4. Line  hen-implant treatment effects on mean (AESEM) length of egg incubation partitioned in rank order as follows: low stress control (397Á8 AE 0Á5 h)4low stress corticosterone-implant (395Á9 AE 0Á7 h)4high stress control (393Á8 AE 0Á3 h)4high stress corticosterone-implant (391Á2 AE 0Á4 h). 5. Our original contention that selection for exaggerated adrenocortical responsiveness is associated with a reduction in the length of egg incubation was supported. Because maternal stress-induced elevations of yolk B are known to occur, the present findings of further shortenings of the hatching times of eggs of corticosterone-treated hens of both stress lines are also important to the poultry industry because they warn producers that unless stress in hens during egg formation is minimised, abbreviated egg incubation periods may result beyond the effects that a hen's genetic predisposition to adrenocortical stress responsiveness has on the length of egg incubation.
Hormones and Behavior, 2012
In vertebrates, stress experienced by mothers during the early stages of reproduction is an important source of epigenetic modifications in their offspring. Birds represent excellent models to test such effects as their maternal investment can be quantified in terms of egg quality. Recently, it has been demonstrated that corticosterone (CORT) can be transmitted from a female bird into its eggs. However, there is little published evidence about maternal effects that are mediated by acute stress. In this study, we demonstrated that female great tits Parus major facing an aerial predator during egg formation increased CORT concentration in eggs that were laid the morning after the treatment. By presenting a predator model to each experimental nest twice a day, we found that maternal stress influences corticosterone content in eggs during a time period from albumen production in the magnum until the initial phase of shell secretion, when additional water is added to the egg in the shell gland. We also found a positive correlation between the duration of parental alarm calls and CORT concentration in eggs.
The aim of this study was to assess the extent to which three non-invasive measures of welfare in laying hens (egg-shell quality, corticosteroid levels as measured from the birds' faeces and behavioural preferences) were correlated over a period of five days in two groups of birds. One group had access to an enriched test area (bark chips on the floor and a tray of sprouted wheat); the other group had access to a comparably sized barren area (bare wire mesh floor). The measure of preference used was the amount of time hens spent in the test area as measured each day. It was predicted that birds with access to the less preferred environ- ment would show higher levels of faecal corticosteroids and egg-shell anomalies. However, although the birds showed a preference for the enriched environment from Day 1, the other two measures did not follow the same pattern. Faecal corticosteroid metabo- lites showed an initial increase in both groups, which declined significantly by Day 4, with...
Applied Animal Behaviour Science, 2007
Previous experiments indicate that artificial elevation of egg corticosterone content prior to incubation may increase fear of humans, reduce the willingness to compete with conspecifics and reduce the growth rate of chicks hatching from these eggs. It can also be hypothesized that corticosterone-treated chicks might be more sensitive to the effects of stress after hatching. Accordingly, we tested the effect of embryonic corticosterone exposure (5.5 ng/ml egg) and intermittent handling after hatching on the behaviour and growth of 88 vehicle-treated (40 males and 48 females) and 88 corticosterone-treated (40 males and 48 females) chicks. The injection treatment did not have any significant effects on tonic immobility (P 0.23), but tended to increase the male's willingness to feed in a competitive environment (P 0.10). However, post-hatch handling increased the duration of tonic immobility in corticosterone-treated birds but not in controls (P 0.01), as reflected in the interaction between the injection and handling treatments (P 0.01). Intermittent handling but not corticosterone treatment reduced the willingness of male birds to eat in a competitive situation, but neither treatment affected this behaviour in females. The present results suggest that the effect of embryonic corticosterone exposure may be dependent on the hormone dosage and the environment to which birds are exposed after hatching.
Physiology & Behavior, 2009
A corticosterone model was used to study the effects of chronic and repeated stress during the rearing phase on physiology, the onset of lay and performance of laying hens in the subsequent laying period. Two hundred and seventy Hy-line brown layer pullets were reared in environmentally controlled battery cages. At 7, 11, and 15 weeks of age birds were exposed for 1 week to the following treatments in drinking water: corticosterone dissolved in ethanol, ethanol, or untreated water. One week following each treatment, and at 35 weeks of age endocrine, metabolic and haematological tests were conducted. Body weight was measured throughout the study, and egg production was recorded daily throughout the laying period. Plasma corticosterone levels and heterophil to lymphocyte (H/L) ratio were increased after each corticosterone delivery, showing the effectiveness of the treatment. When corticosterone delivery was interrupted, plasma corticosterone and H/L ratio were significantly reduced. Exposing birds to repeated and long-term corticosterone treatment significantly affected BW (P b 0.01), and relative organ weights (P b 0.01). Corticosterone delivery also resulted in increased blood levels of glucose (GLU), cholesterol (CHOL), and triglyceride (TRG). Administration of corticosterone during the rearing phase delayed the onset of lay and decreased egg production at 35 weeks of age. These results demonstrate that oral corticosterone treatment affects hen physiology, reduces performance, and may model the effects of production stressors.
The effects of furnished cages on the behaviour of laying hens in the post-stress adaptation period
Journal of Istanbul Veterinary Sciences
The aim of the study is to investigate whether housing laying hens in furnished cages in post-stress adaptation period causes any changes in behaviors or not. Due to the affects of animal welfare on production performance, the relationship between behavioral changes and egg production has also been studied. In the present study, 22 weeks old, 32 laying hens were used. The hens were subjected to transport. The transport procedure, including loading and unloading took 8 hours. Just after the transportation, birds were randomly divided into two groups as furnished and conventional cages; each consists of two subgroups with 8 hens. It was ensured that the hens in subgroups were unfamiliar with each other to induce social stress. On the top of each cage, a camera was fixed and continuous recording was done for 24 hours for 6 days. The behavior of animals was scored by time sampling method. Eating, drinking, resting, preening, wing flapping, tail-wagging, stretching, ground-scratching, gentle pecking, stereotyped and aggressive pecking behaviors were scored. In addition, the locations of the hens were also determined in furnished cages. Frequency of eating, drinking and ground-scratching behaviours significantly increased, but tail-wagging behaviour tended to increase in hens housed in furnished cages. On the other hand, resting, stretching and aggressive pecking behaviours significantly decreased in hens housed in furnished cages. In addition, the use of perch and nest rate in furnished cages significantly increased from the second day. In the conclusion, cage furnishing improves some comfort behaviour such as ground-scratching and tail wagging and decreasing aggressive pecking in laying hens. Therefore, it would be beneficial to keep stress-exposed hens in furnished cages in the post-stress adaptation period.