The effect of feeding a high fibre diet on the welfare of sows housed in large dynamic groups

This study assessed the effect of increasing fibre levels in the concentrate ration on the welfare of sows housed in a large dynamic group. One hundred and twelve Large White x Landrace sows were allocated to one of two treatments over six replicates. Treatments were as follows: (i) High Fibre diet (similar to 15% CF [Crude Fibre]), and (ii) Control diet (similar to 5% CF). Treatments were applied to two separate dynamic groups each containing 33 (+/- 3) sows in a cross-over design, after three replicates the treatments were switched between the groups. Approximately nine sows were replaced in each of these groups at 3-week intervals (each replacement constituting a replicate of the study). Sows on the high fibre diet spent a greater percentage of time lying (High Fibre: 43.8, Control. 28.0, SEM 3.25%), while sows on the control diet spent more time sham chewing (High Fibre: 7.2, Control: 28.8, SEM 1.55%). Sows newly introduced to the group on the high fibre treatment spent proportionally more time in the kennel areas compared to newly introduced sows in the control treatment (High Fibre. 0.893, Control. 0 788, SEM 5 10) In general, aggression occurred at a very low frequency and overall levels did not differ between treatments (High Fibre: 0.005, Control: 0.003, SEM 0.0007 [occurrences per min)). However, sows in the control treatment performed head thrusting (High Fibre: 0.02, Control: 0.00, SEM 0.001 [occurrences per mini), and biting behaviour (High Fibre. 002, Control. 0.01, SEM 0.002 [occurrences per min]) more frequently than sows on the high fibre diet. There was no effect of treatment on physiological parameters such as plasma cortisol (High Fibre: 1.34, Control: 1.44, SEM 0.114 ng ml(-1)) or haptoglobin levels (High Fibre. 0.73, Control. 0.64, SEM 0.080 mg ml(-1)). In summary, provision of a high fibre diet had a positive effect on the welfare of group-housed dry sows Sows on the high fibre treatment spent more time resting in the kennel areas, less time performing stereotypic behaviours and showed a reduction in some aggressive behaviours relative to sows fed the control diet.

Influence of social status on the welfare of growing pigs housed in barren and enriched environments

One hundred and twenty-eight pigs were reared in barren or enriched environments from birth to slaughter at 21 weeks of age. Pigs remained as litter-mate groups until 8 weeks of age when they were mixed into groups of eight animals. These groups were balanced for gender and weight and contained two pigs from each of four different litters. Each pig was assigned high or low social status on the basis of relative success in aggressive interactions at mixing. Injury levels were assessed on a weekly basis from 8 to 2 1 weeks of age. Pigs were exposed to two group food competition tests after a period of food restriction at 10 weeks of age, and to an individual novel pen test at 11 weeks of age. Behavioural and plasma cortisol responses to both types of test were recorded. Low social status was associated with increased injuries to the head, neck and ears, and therefore reduced welfare. Pigs with low social status showed reduced resource-holding ability in the food competition test, and greater avoidance of a novel object during the novel pen test. It is suggested that avoidance of the novel object reflected 'learned' fearfulness in these individuals. Environmental enrichment did not negate the effect of low social status on injury levels, but did appear to reduce the negative influence of low social status on stress during food restriction, and led to a reduction in fearfulness in response to the novel pen test. These results suggest that environmental enrichment may improve the we/fare of growing pigs with low social status.

Alternative reproductive tactics in male Cape ground squirrels Xerus inauris

In some animal societies, males vary in the strategies and tactics that they use for reproduction. Explanations for the evolution of alternative tactics have usually focussed on extrinsic factors such as social status, the environment or population density and have rarely examined proximate differences between individuals. Anecdotal evidence suggests that two alternative reproductive tactics occur in cooperatively breeding male Cape ground squirrels. Here we show that there is strong empirical support for physiological and behavioural differences to uphold this claim. `Dispersed' males have higher resting metabolic rates and a heightened pituitary activity, compared with philopatric 'natal' males that have higher circulating cortisol levels. Dispersed males also spend more time moving and less time feeding than natal males. Additionally, lone males spend a greater proportion of their time vigilant and less of their time foraging than those that were in groups. The choice of whether to stay natal or become a disperser may depend on a number of factors such as age, natal group kin structure and reproductive suppression, and the likelihood of successful reproduction whilst remaining natal. Measuring proximate factors, such as behavioural and endocrine function, may provide valuable insights into mechanisms that underlie the evolution of alternative reproductive tactics.

Endocrine disrupting effects of zearalenone, alpha- and beta-zearalenol at the level of nuclear receptor binding and steroidogenesis.

The mycotoxin zearalenone (ZEN) is a secondary metabolite of fungi which is produced by certain species of the genus Fusarium and can occur in cereals and other plant products. Reporter gene assays incorporating natural steroid receptors and the H295R steroidogenesis assay have been implemented to assess the endocrine disrupting activity of ZEN and its metabolites -zearalenol (-ZOL) and -zearalenol (-ZOL). -ZOL exhibited the strongest estrogenic potency (EC50 0.022 ± 0.001 nM), slightly less potent than 17- estradiol (EC50 0.015 ± 0.002 nM). ZEN was ~70 times less potent than -ZOL and twice as potent as -ZOL. Binding of progesterone to the progestagen receptor was shown to be synergistically increased in the presence of ZEN, -ZOL or -ZOL. ZEN, -ZOL or -ZOL increased production of progesterone, estradiol, testosterone and cortisol hormones in the H295R steroidogenesis assay, with peak productions at 10 M. At 100 M, cell viability decreased and levels of hormones were significantly reduced except for progesterone. -ZOL increased estradiol concentrations more than -ZOL or ZEN, with a maximum effect at 10 M, with -ZOL (562 ± 59 pg/ml) > -ZOL (494 ± 60 pg/ml) > ZEN (375 ± 43 pg/ml). The results indicate that ZEN and its metabolites can act as potential endocrine disruptors at the level of nuclear receptor signalling and by altering hormone production.

A PHARMACOKINETIC AND PHARMACODYNAMIC COMPARISON OF PLAIN AND ENTERIC-COATED PREDNISOLONE TABLETS

1 Eight healthy volunteers and eight patients suffering from chronic obstructive pulmonary disease (COPD) received 30 mg prednisolone as plain (P) and enteric-coated tablets (EP) in a randomised, cross-over manner. Plasma prednisolone and cortisol and blood glucose were measured over 24 h.

Structure-Phenotype Correlations of Human CYP21A2 Mutations in Congenital Adrenal Hyperplasia

Congenital Adrenal Hyperplasia (CAH) is a family of autosomal recessive disorders involving impaired synthesis of cortisol from cholesterol by adrenal cortex. The predominant causes of the disorder are mutations in the CYP21A2 gene that encodes a Cytochrome P450 21-hydroxylase enzyme, which is central to steroidogenesis. The severity of the disease depends upon the extent of impaired enzymatic activity and can be classified under severe Classical form or the mild Non-Classical form, Molecular characterisation of CYP21A2 mutations can be used to predict clinical phenotype and disease severity based upon changes it brings in 21-hydroxylase enzyme structure. A humanized model of CYP21A2 has been used to map and investigate the structural role of all known disease-causing mutations. A structural explanation of clinical manifestation allows us to put forward criteria that might allow the prediction of clinical severity of the disease.

Contingency Learning and Reactivity in Preterm and Full-Term Infants at 3 Months

Learning difficulties in preterm infants are thought to reflect impairment in arousal regulation. We examined relationships among gestational age, learning speed, and behavioral and physiological reactivity in 55 preterm and 49 full-term infants during baseline, contingency, and nonreinforcement phases of a conjugate mobile paradigm at 3 months corrected age. For all infants, negative affect, looking duration, and heart rate levels increased during contingency and nonreinforcement phases, whereas respiratory sinus arrhythmia (RSA, an index of parasympathetic activity) decreased and cortisol did not change. Learners showed greater RSA suppression and less negative affect than nonlearners. This pattern was particularly evident in the preterm group. Overall, preterm infants showed less learning, spent less time looking at the mobile, and had lower cortisol levels than full-term infants. Preterm infants also showed greater heart rate responses to contingency and dampened heart rate responses to nonreinforcement compared to full-term infants. Findings underscore differences in basal and reactivity measures in preterm compared to full-term infants and suggest that the capacity to regulate parasympathetic activity during a challenge enhances learning in preterm infants.

Growth and adrenal suppression in asthmatic children treated with high-dose fluticasone propionate

Background: Fluticasone propionate was introduced in 1993 in the UK as a potentially safer inhaled corticosteroid than those already in use. The efficacy and safety of fluticasone has been established at recommended doses of 200 µg/day, but not at the higher doses that are often used.

Methods: Growth retardation was observed in six severely asthmatic children after introduction of high-dose fluticasone propionate treatment (dry powder). Assessment of cortisol response was by insulin-induced hypoglycaemia in three cases, by short tetracosactrin test in two, and by low-dose tetracosactrin and 24-hour urinary cortisol/creatinine ratio in one.

Findings: Six children with growth retardation noted after treatment with high-dose fluticasone propionate were found to have adrenal suppression. In one case the growth rate and cortisol response returned to normal 9 months after the fluticasone dose was reduced to 500 µg/day.

Interpretation: When high doses of fluticasone propionate are used, growth may be retarded and adrenal suppression may occur.

Behavioural and physiological responses of heifer calves to acute stressors: long-term consistency and relationship with adult reactivity to milking

The present study investigated the long-term consistency of individual differences in dairy cattles’ responses in tests of behavioural and hypothalamo–pituitary–adrenocortical (HPA) axis reactivity, as well as the relationship between responsiveness in behavioural tests and the reaction to first milking. Two cohorts of heifer calves, Cohorts 1 (N = 25) and 2 (N = 16), respectively, were examined longitudinally from the rearing period until adulthood. Cohort 1 heifers were subjected to open field (OF), novel object (NO), restraint, and response to a human tests at 7 months of age, and were again observed in an OF test during first pregnancy between 22 and 24 months of age. Subsequently, inhibition of milk ejection and stepping and kicking behaviours were recorded in Cohort 1 heifers during their first machine milking. Cohort 2 heifers were individually subjected to OF and NO tests as well as two HPA axis reactivity tests (determining ACTH and/or cortisol response profiles after administration of exogenous CRH and ACTH, respectively) at 6 months of age and during first lactation at approximately 29 months of age. Principal component analysis (PCA) was used to condense correlated response measures (to behavioural tests and to milking) within ages into independent dimensions underlying heifers’ reactivity. Heifers demonstrated consistent individual differences in locomotion and vocalisation during an OF test from rearing to first pregnancy (Cohort 1) or first lactation (Cohort 2). Individual differences in struggling in a restraint test at 7 months of age reliably predicted those in OF locomotion during first pregnancy in Cohort 1 heifers. Cohort 2 animals with high cortisol responses to OF and NO tests and high avoidance of the novel object at 6 months of age also exhibited enhanced cortisol responses to OF and NO tests at 29 months of age. Measures of HPA axis reactivity, locomotion, vocalisation and adrenocortical and behavioural responses to novelty were largely uncorrelated, supporting the idea that stress responsiveness in dairy cows is mediated by multiple independent underlying traits. Inhibition of milk ejection and stepping and kicking behaviours during first machine milking were not related to earlier struggling during restraint, locomotor responses to OF and NO tests, or the behavioural interaction with a novel object. Heifers with high rates of OF and NO vocalisation and short latencies to first contact with the human at 7 months of age exhibited better milk ejection during first machine milking. This suggests that low underlying sociality might be implicated in the inhibition of milk ejection at the beginning of lactation in heifers.

An in vitro investigation of endocrine disrupting effects of the mycotoxin alternariol

Alternariol (AOH) is a mycotoxin commonly produced by Alternaria alternata on a wide range of foods. Few studies to date have been performed to evaluate the effects of AOH on endocrine activity. The present study makes use of in vitro mammalian cellular based assays and gene expression to investigate the ability of AOH to act as an endocrine disruptor by various modes of action. Reporter gene assays (RGAs), incorporating natural steroid hormone receptors for oestrogens, androgens, progestagens and glucocorticoids were used to identify endocrine disruption at the level of nuclear receptor transcriptional activity, and the H295R steroidogenesis assay was used to assess endocrine disruption at the level of gene expression and steroid hormone production. AOH exhibited a weak oestrogenic response when tested in the oestrogen responsive RGA and binding of progesterone to the progestagen receptor was shown to be synergistically increased in the presence of AOH. H295R cells when exposed to 0.1-1000ng/ml AOH, did not cause a significant change in testosterone and cortisol hormones but exposure to 1000ng/ml (3.87µM) AOH resulted in a significant increase in estradiol and progesterone production. In the gene expression study following exposure to 1000ng/ml (3.87µM) AOH, only one gene NR0B1 was down-regulated, whereas expression of mRNA for CYP1A1, MC2R, HSD3B2, CYP17, CYP21, CYP11B2 and CYP19 was up-regulated. Expression of the other genes investigated did not change significantly. In conclusion AOH is a weak oestrogenic mycotoxin that also has the ability to interfere with the steroidogenesis pathway.

Mifepristone, a glucocorticoid receptor antagonist, produces clinical and metabolic benefits in patients with Cushing's syndrome

Cushing's syndrome (CS) is a disorder associated with significant morbidity and mortality due to prolonged exposure to high cortisol concentrations.

Identification of serum stress biomarkers in pigs housed at different stocking densities

Eight Duroc × (Landrace × Large White) male pigs housed at a stocking rate of 0.50 m2/pig were subjected to a higher stocking rate of 0.25 m2/pig (higher density, HD) for two 4-day periods over 26 days. Using biochemical and proteomic techniques serum and plasma samples were examined to identify potential biomarkers for monitoring stress due to HD housing. HD housed pigs showed significant differences (P < 0.001) in total cholesterol and low density lipoprotein-associated cholesterol, as well as in concentrations of the pig-major acute phase protein (Pig-MAP) (P = 0.002). No differences were observed in serum cortisol or other acute phase proteins such as haptoglobin, C-reactive protein or apolipoprotein A–I. HD-individuals also showed an imbalance in redox homeostasis, detected as an increase in the level of oxidized proteins measured as the total plasma carbonyl protein content (P < 0.001) with a compensatory increase in the activity of the antioxidant enzyme glutathione peroxidase (P = 0.012). Comparison of the serum proteome yielded a new potential stress biomarker, identified as actin by mass spectrometry. Cluster analysis of the results indicated that individuals segregated into two groups, with different response patterns, suggesting that the stress response depended on individual susceptibility.

Effects of the mycotoxin patulin at the level of nuclear receptor transcriptional activity and steroidogenesis in vitro

Patulin (PAT) is a mycotoxin produced by various species of fungi, with Penicillium expansum being the most commonly occurring. Apples and apple products are the main sources of PAT contamination. This mycotoxin has been shown to induce toxic effects in animals, a few of which include reproductive toxicity and interference with the endocrine system. Here the endocrine disrupting potential of PAT has been investigated in vitro to identify disruption at the level of oestrogen, androgen, progestagen and glucocorticoid nuclear receptor transcriptional activity, and to assess interferences in estradiol, testosterone and progesterone steroid hormone production. At the receptor level, 0.5-5000ng/ml (0.0032-32μM) PAT did not appear to induce any specific (ant) agonistic responses in reporter gene assays (RGAs); however, nuclear transcriptional activity was affected. A >6 fold increase in the glucocorticoid receptor transcriptional activity was observed following treatment with 5000ng/ml PAT in the presence of cortisol. At the hormone production level, despite cytotoxicity being observed after treatment with 5000ng/ml PAT, estradiol levels had increased >2 fold. At 500ng/ml PAT treatment, an increase in progesterone and a decrease in testosterone production were observed. The findings of this study could be considered in assessing the health risks following exposure to PAT.

An investigation of the endocrine disrupting potential of enniatin B using in vitro bioassays

Evidence that some of the fungal metabolites present in food and feed may act as potential endocrine disruptors is increasing. Enniatin B (ENN B) is among the emerging Fusarium mycotoxins known to contaminate cereals. In this study, the H295R and neonatal porcine Leydig cell (LC) models, and reporter gene assays (RGAs) have been used to investigate the endocrine disrupting activity of ENN B. Aspects of cell viability, cell cycle distribution, hormone production as well as the expression of key steroidogenic genes were assessed using the H295R cell model. Cell viability and hormone production levels were determined in the LC model, while cell viability and steroid hormone nuclear receptor transcriptional activity were measured using the RGAs. ENN B (0.01–100 μM) was cytotoxic in the H295R and LC models used; following 48 h incubation with 100 μM. Flow cytometry analysis showed that ENN B exposure (0.1–25 μM) led to an increased proportion of cells in the S phase at higher ENN B doses (>10 μM) while cells at G0/G1 phase were reduced. At the receptor level, ENN B (0.00156–15.6 μM) did not appear to induce any specific (ant) agonistic responses in reporter gene assays (RGAs), however cell viability was affected at 15.6 μM. Measurement of hormone levels in H295R cells revealed that the production of progesterone, testosterone and cortisol in exposed cells were reduced, but the level of estradiol was not significantly affected. There was a general reduction of estradiol and testosterone levels in exposed LC. Only the highest dose (100 μM) used had a significant effect, suggesting the observed inhibitory effect is more likely associated with the cytotoxic effect observed at this dose. Gene transcription analysis in H295R cells showed that twelve of the sixteen genes were significantly modulated (p < 0.05) by ENN B (10 μM) compared to the control. Genes HMGR, StAR, CYP11A, 3βHSD2 and CYP17 were downregulated, whereas the expression of CYP1A1, NR0B1, MC2R, CYP21, CYP11B1, CYP11B2 and CYP19 were upregulated. The reduction of hormones and modulation of genes at the lower dose (10 μM) in the H295R cells suggests that adrenal endocrine toxicity is an important potential hazard.

Physiological stress in the Eurasian badger (Meles meles): Effects of host, disease and environment

A method for monitoring hypothalamic–pituitary–adrenal (HPA) responses of the Eurasian badger (Meles meles) to stressors was validated by measuring cortisol excretion in serum and faeces. Serum and faecal samples were collected under anaesthesia from live-captured, wild badgers and fresh faeces was collected from latrines at 15 social groups in County Down, Northern Ireland. Variation in levels of cortisol in wild badgers was investigated relative to disease status, season, age, sex, body mass, body condition and reproductive status and environmental factors that might influence stress. Faecal cortisol levels were significantly higher in animals testing culture-positive for Mycobacterium bovis. Prolonged elevation of cortisol can suppress immune function, which may have implications for disease transmission. There was a strong seasonal pattern in both serum cortisol, peaking in spring and faecal cortisol, peaking in summer. Cortisol levels were also higher in adults with poor body condition and low body mass. Faecal samples collected from latrines in grassland groups had significantly higher cortisol than those collected from woodland groups, possibly as a result of greater exposure to sources of environmental stress. This study is the first to investigate factors influencing physiological stress in badgers and indicates that serological and faecal excretion are valid indices of the HPA response to a range of stressors.