Corticosterone Metabolites In Droppings Research Articles

Multifactorial Evaluation of Regrouping Effects on Performance and Welfare in Two Italian Dual-Purpose Chicken Breeds: Bianca di Saluzzo and Bionda Piemontese.

Simple SummaryLocal chicken breeds Bionda Piemontese (BP) and Bianca di Saluzzo (BS) are promising for use in small-scale poultry farms, which adopt free-range and/or organic farming practice. However, in practical conditions, it can happen that animals are subjected to regrouping, creating a new flock by mixing different groups. Such situations may provoke a stressful response in birds, compromising their welfare. To evaluate the resilience of BP and BS breeds to adverse management practices (regrouping), the present study aimed to assess the birds’ welfare status through a multifactorial approach. As a result, the practice of regrouping immediately compromised the welfare status and the productive performances in both BP and BS hens, but, in the following weeks, birds displayed a reliance, which help them adapt to the new stressful conditions. The aim of the present study was to investigate the ability of two Italian slow-growing poultry breeds (namely, Bionda Piemontese, BP, and Bianca di Saluzzo, BS) to cope with a stressful event, such as collective grouping, using a multifactorial approach. A total of 120 hens of BP and BS breeds were homogenously distributed, according to breed, in 12 pens (10 hens/pen; 6 pens/breed), from 18 to 49 weeks of age. At 50 weeks of age, hens were regrouped (Stressful Farm Practice, SFP), by removing separators, both in indoor and outdoor areas. At 49 weeks of age, 24 hens/breed were randomly selected for the evaluation of welfare (ethological and physiological) parameters, at different time points: T0: 1-week pre-SPF; T1: 1-week post-SFP; T2: 3-week post-SFP; T3: 5-week post-SFP. Egg production was recorded from 38 to 56 weeks of age. Grouping produced a social stress in both BS and BP-laying hens, which was expressed in terms of productive traits (reduction of oviposition), behavioral modification (worsening of plumage condition due to feather peaking and extension of the duration of the tonic immobility test) and physiological modification (increased heterophil/lymphocyte ratio and corticosterone metabolites in droppings). Both breeds reacted in a similar way; in fact, no differences were attributed to the breed. At the end of the observation period, the egg rate fully recovered, while the behavioral and physiological parameters partially recovered but failed to recover to those recorded prior to the stressful event.

Glucocorticoid response to both predictable and unpredictable challenges detected as corticosterone metabolites in collared flycatcher droppings.

In most vertebrate animals, glucocorticoid hormones are the chief mediators of homeostasis in response to ecological conditions and as they progress through their lifecycle. In addition, glucocorticoids are a major part of the stress response and stress induced elevations of the hormone can make it difficult to assess glucocorticoid secretion in response to changes in life-stage and current environmental conditions in wild animals. Particularly when quantifying circulating levels of glucocorticoids in the blood which fluctuate rapidly in response to stress. An alternative method of quantifying glucocorticoids is as hormone metabolites in faeces or urine giving a historical sample related to the gut passage time and urinary tract that is less sensitive to stressful events which cause spikes in the circulating hormone level. Although the concentration of glucocorticoid metabolites are influenced by faecal mass thereby potentially affecting any differences in hormone metabolites detected amongst samples. In the present study, we aimed to detect changes in levels of corticosterone, the primary bird glucocorticoid, in relation to the phase of reproduction, in a breeding population of collared flycatchers by sampling corticosterone metabolites in droppings. We also tested how corticosterone metabolite concentrations were affected by ambient temperature and related to body condition in adult birds. Our results indicate that the upregulation of corticosterone between incubation and nestling feeding in female birds is crucial for successful reproduction in this species. Also, females appear to downregulate corticosterone during incubation in response to lower ambient temperature and poorer body condition. Our results did not indicate a relationship between dropping mass and corticosterone metabolite concentrations, which suggests that our findings were linked to the regulation of corticosterone in response to predictable and unpredictable challenges.

Lipids in maternal diet influence yolk hormone levels and post-hatch neophobia in the domestic chick.

We assessed whether the ratio of dietary n-6/n-3 polyunsaturated fatty acids (PUFA) during egg formation engenders transgenerational maternal effects in domestic chicks. We analyzed yolk lipid and hormone concentrations, and HPA-axis activity in hens fed a control diet (high n-6/n-3 ratio) or a diet enriched in n-3 PUFAs (low n-6/n-3 ratio) for 6 consecutive weeks. Their chicks were tested for neophobia during the first week of life. We found higher corticosterone metabolites in droppings of hens fed the diet enriched in n-3 and significantly higher concentrations of yolk progesterone, androstenedione, and estradiol in their eggs compared to controls. Chicks of hens fed the n-3 enriched diet showed a lower body mass at hatch than controls and expressed higher neophobia when exposed to a novel object. These results add support to the hypothesis that the nutritional state of female birds produces variation in yolk hormone levels and engender maternal effects.

An association between feather damaging behavior and corticosterone metabolite excretion in captive African grey parrots (Psittacus erithacus).

BackgroundAfrican grey parrots (Psittacus erithacus) are kept as pets and are frequently hand-reared. It has been observed that hand-reared African grey parrots may develop behavioral disorders such as feather damaging behavior (FDB). It is well known that chronic stress is involved in behavioral disorders in captive parrots. The main glucocorticoid in birds is corticosterone; its quantification provides information about adrenocortical activity and is considered to be a reliable indicator of stress levels in birds. We analyzed the differences in the excretion of corticosterone metabolites (CM) in the droppings of African grey parrots characterized by: 1. different rearing histories (parent rearing vs. hand rearing); and 2. the presence or absence of FDB in hand-reared parrots.MethodsA total of 82 African grey parrots that were kept in captivity were considered. According to breeding methods, three groups of birds were defined: 1. The parent-reared (PR) parrots included birds kept in pairs (n = 30 pairs) with a conspecific partner of the opposite sex. All of these birds were healthy and never showed FDB signs; 2. The healthy hand-reared parrots (H-HR) included pet parrots individually kept, that were hand-reared and did not display any sign of FDB (n = 11, 7 males and 4 females); 3. The FDB hand-reared parrot (FDB-HR) included pet parrots individually kept, that were hand-reared and displayed FDB (n = 11, 7 males and 4 females). Droppings were collected in the morning over three alternating days in autumn 2014 and spring 2015. The CM were determined using a multi-species corticosterone enzyme immunoassay kit. Split-plot repeated-measure ANOVA was used to examine any differences using group, season and group × season as the main factors.ResultsDifferent quantities of CM in droppings were found for the three groups. The mean CM value was 587 ng/g in the PR parrots, 494 ng/g in the H-HR parrots and 1,744 ng/g in the FDB-HR parrots, irrespective of the season. The excretion of CM in FDB-HR was significantly higher than in PR or H-HR parrots. CM in droppings were not influenced by the season (autumn vs. spring); furthermore, the interaction between group and sampling season was not significant. Limited to the H-HR and FDB-HR groups, a trend in the significance of the difference in the mean CM excreted by male and female birds was observed, with the levels excreted by males being higher than those excreted by females. When the effect of age was considered (in the two separate groups), there was a statistically significant positive correlation only for H-HR.ConclusionsThe highest amount of CM excretion was found in FDB-HR parrots, and a positive correlation between age and CM excretion was found in H-HR. Given that the CM excretion of both PR and H-HR parrots was similar in our study, future research is recommended to investigate the specific aspects of hand-rearing to improve parrot welfare.

Welfare indicators in laying hens in relation to nest exclusion

Consumer concerns about the welfare of laying hens are increasing, leading to increased interest in identifying reliable ways to assess welfare. The present study evaluated invasive and non-invasive welfare indicators in relation to a stressful challenge. The study included 126 Lohmann Selected Leghorn hens housed in furnished cages. Welfare indicators were measured between 61 and 70 wk of age in birds excluded from their nests for 5 consecutive d and control birds that had continuous access to nests. Baseline recordings were carried out in both groups prior to and post exclusion period. The assessed indicators were: corticosterone metabolites in droppings (FCM), corticosterone concentration in yolk, corticosterone concentration in plasma, irregularities of eggshells, heterophil to lymphocyte (H:L) ratio, tonic immobility duration, and feather cover. Behavioral observations showed that the birds had a clear preference for using the secluded nest sites, confirming that they were likely to perceive nest exclusion as an undesirable experience. Further, elevated levels of FCM in droppings, yolk corticosterone concentrations, H:L ratios and irregular eggshells were detected in both nest deprived and control birds during the exclusion. This suggests that these indicators were able to detect an increased stress response arising from nest deprivation, and it is hypothesized that the stress spread to birds in adjacent cages with access to nests. There was a positive and consistent correlation between FCM in droppings and eggshell irregularities, also supporting the use of eggshell irregularities as a potential non-invasive welfare indicator. However, the pattern of the stress response varied between indicators and correlations were generally few and inconsistent, highlighting the complexity of the relationship among welfare indicators.

Corticosterone, Avoidance of Novelty, Risk‐Taking and Aggression in a Wild Bird: No Evidence for Pleiotropic Effects

AbstractCertain inherent characteristics of individuals can determine both physiological and behavioural responses to environmental challenges, which could drive a correlation between levels of corticosterone (CORT), the most important stress hormone and behavioural profiles. Therefore, CORT level may mediate consistent behaviours along the shy/bold continuum, and thus, it could serve as a pleiotropic basis for behavioural syndromes. Moreover, behavioural responses to environmental challenges may have consequences for CORT concentrations, which would also result in a correlation between physiology and behaviours even without requiring pleiotropic mechanisms. Accordingly, we investigated the relationship between CORT and behaviour in free‐living male collared flycatchers, Ficedula albicollis, using recently developed field assays. More specifically, we characterised novel object avoidance, intraspecific aggression and risk‐taking in males and related these correlated behaviours to the concentration of CORT metabolites in droppings measured by enzyme immunoassay. Individuals with higher levels of excreted CORT metabolites had no consistently higher or lower behavioural scores along the shy/bold spectrum, as avoidance of novelty, aggression and risk‐taking were not systematically related to CORT metabolite concentrations in the same direction. Moreover, environmental challenges owing to the presence of a novel object, territorial intruder and a potential predator caused no elevation in the level of CORT metabolites. Therefore, we did not find correlative evidence for CORT driving correlated behaviours through pleiotropic effects or for particular behaviours during courtship causing elevation in CORT levels.

Excreted corticosterone metabolites differ between two galliform species, Japanese Quail and Chicken, between sexes and between urine and faecal parts of droppings

Japanese Quail (Coturnix japonica) are a common avian laboratory model, and measuring corticosterone metabolites (CM) non-invasively from Quail droppings would be of broad interest. Using the enzyme immunoassay suitable for measuring CM in droppings of Chicken (Gallus domesticus) and other galliform species, we tested the CM measured in Quail droppings after stimulation with adrenocorticotropic hormone. An ACTH challenge indicated that the assay did not detect major amounts of CM in Japanese Quail excreta. Therefore, we aimed at testing whether steroid metabolism and clearance differed between closely related species. We compared the CM excretion patterns in male and female Japanese Quail and Chicken. After intravenous injection with [3H]-labelled corticosterone, we collected all droppings for 24 h, including caecum excreta. Males and females of both species excreted radioactive CM with two peaks. The first radioactivity-peak presumably was from uric acid (Quail 45/55 min; Chicken 120/75 min post-injection, males/females respectively), whereas the second peak probably represented faecal excretion (180/210 min; 240/140 min, respectively). Several highly polar radioactive CM, but no corticosterone, was separated by chromatography in droppings of both species. Number and identity of CM considerably differed between males and females, as well as between urine and faecal excretion. The nature of excreted CM in Quail droppings remains unresolved. However, we show that knowing the effective time for dropping collection is essential for interpreting stimulus-specific CM responses, and mixing samples from rapid urine and slower faecal excretion should be avoided.

Reducing stress during welfare inspection: validation of a non-intrusive version of the LayWel plumage scoring system for laying hens

1. The objectives of the present study were to validate a reduced, non-intrusive version (RLS) of the LayWel plumage scoring system in domestic laying hens with reference to complete, intrusive scoring (CLS) and to investigate the effect of these two scoring methods on corticosterone metabolite concentrations. 2. A total of 312 medium-heavy laying hens from 4 commercial hybrids kept in 24 floor pens were scored by two experienced teams. Another 150 hens from two hybrids kept in 6 pens were used for estimating scoring treatment effects on corticosterone metabolites in droppings. 3. Plumage scores were in general higher using the RLS method compared to the CLS method. The agreement between teams for plumage scores (CLS) were on a high (total score) to an excellent (single body part except breast and cloaca) level. 4. Birds subjected to CLS tended to have higher concentrations of corticosterone metabolites in droppings 2 h after scoring compared with birds in the control treatment (not scored). Birds subjected to RLS had intermediate concentrations. 5. It was concluded that a reduced version of the LayWel scoring system is a valid and reliable scoring method which tends to induce less stress to the subjects than the original procedure.

Stocking density effects on broiler welfare: Identifying sensitive ranges for different indicators

Although stocking density is perceived as a topic of major importance, no consensus has been reached on what density would allow for good welfare. In the present study, the welfare of 4 replicates of birds stocked at 8, 19, 29, 40, 45, 51, 61, and 72 broilers per pen (or 6, 15, 23, 33, 35, 41, 47, and 56 kg actually achieved BW/m2) was studied using 6 welfare indicators. Density did not affect bursa weight, mortality, or concentrations of corticosterone metabolites in droppings but did influence leg health (P = 0.015) and footpad and hock dermatitis (P < 0.001) and tended to influence fearfulness (P = 0.078). However, not every increase in density or group size, or both, led to poorer welfare for the affected indicators: leg health and fearfulness showed unexpected peaks at intermediate densities. Furthermore, the indicators were influenced at different densities: leg strength showed a steep decrease from 6 to 23 kg/m2, hock dermatitis rose from 35 to 56 kg/m2, and footpad dermatitis and fearfulness were only significantly higher at the highest density of 56 kg/m2. No threshold stocking density above which all aspects of welfare were suddenly altered was found in this study. Instead, different aspects of welfare were influenced at different densities or group sizes, or both. Thus, evaluating the effects of stocking density on welfare as a whole would require either identification of acceptable levels for each separate indicator or a weighting of the indicators in an integrated welfare score. A tentative attempt to such an integration, made using equal weights for all parameters, showed a decrease in welfare as density increased (P < 0.001). The lowest 2 densities (6 and 15 kg/m2) scored better than most middle densities (23, 33, 35, and 47 kg/m2), whereas all densities scored better than the highest density (56 kg/m2).