Abstract: This paper describes the results of a series of studies showing that variations in mother-pup interactions program the development of individual differences in behavioral and endocrine stress responses in the rat. These effects are associated with altered expression of genes in brain regions, such as the amygdala, hippocampus, and hypothalamus, that regulate the expression of stress responses. Studies from evolutionary biology suggest that such “maternal effects” are common and often associated with variations in the quality of the maternal environment. Together these findings suggest an epigenetic process whereby the experience of the mother alters the nature of the parent-offspring interactions and thus the phenotype of the offspring.

Abstract: A multitude of endocrine mechanisms are involved in coping with challenges. Glucocorticoids, secreted by the adrenal glands, are in the front line of the battle to overcome stressful situations. They are usually measured in plasma samples as parameters of adrenal activity and thus of disturbance. Unfortunately, collecting blood samples itself can disturb an animal. Thus, non-invasive methods for the determination of glucocorticoids or their metabolites have become increasingly popular. The pros and cons of various non-invasive sample materials (saliva, excreta, milk, hair/feathers and eggs) for glucocorticoid determination are given. Above all, faecal samples offer the
advantage that they can be collected easily. In faecal samples, circulating hormone levels are integrated over a certain period of time and represent the cumulative secretion of hormones. Thus, the levels are less affected by short fluctuations or the pulse-like nature of hormone secretion. However, using this technique to assess an animal’s adrenocortical activity is not especially simple. Whether frequent sampling is necessary or single samples will suffice depends upon the study’s aim (whether one is examining the impact of acute or chronic stressors). Background knowledge of the metabolism and excretion of cortisol/corticosterone metabolites is required and a careful validation for each species and sex investigated is obligatory. The present review also addresses analytical issues regarding sample storage, extraction procedures and immunoassays and includes a comprehensive list of published studies (up to 2011) describing the use of such methods in farmed animals. Applied properly, non-invasive techniques to monitor glucocorticoid metabolites in faecal samples of various species are a useful tool for welfare assessment, especially as they are easily applied at farm or group level.

Abstract: Rescued equids are often exposed to rehabilitation and training (or retraining) programmes to improve their physical and psychological well-being as well as to facilitate the re-homing process. Training uses either positive or negative reinforcement learning procedures and it is considered here that, there may be welfare implications associated with using the latter technique as it has the potential to overlay acute stress on animals with a chronic stress life history. The aim of this study, therefore, was to compare these training strategies (negative versus positive reinforcement) on equine behaviour and physiology as the first step in establishing an optimal rehabilitation approach (from a welfare perspective) for equids that have been subjected to chronic stress in the form of long-term neglect/cruelty. Over a 7-week period, 16 ponies (aged 6–18 months) were trained using either positive (‘positive’) (n = 8) or negative reinforcement (‘negative’) (n = 8) techniques to lead in hand, stand to be groomed, traverse an obstacle course and load into a trailer. Heart rate was measured (5 s intervals) on days 1 and 4 of each training week, ‘Pre’- (1 h), ‘During’ (0.5 h) and ‘Post’- (1 h) training session. Ethograms (10.00–20.00 h) outside of the training period were also compiled twice weekly. In addition, weekly arena tests (as a measure of reactivity) were also performed 1 week before and during the 7 weeks of training. Results showed significant differences between the two training schedules for some measures during the latter stages of the trial and suggested that animals trained under a positive reinforcement schedule were more motivated to participate in the training sessions and exhibited more exploratory or ‘trial and error’ type behaviours in novel situations/environments. In this context, the incorporation of positive reinforcement schedules within a rehabilitation programme may be of benefit to the animal from a welfare perspective.

Abstract: Adult male elephants periodically show the phenomenon of musth, a condition associated with increased aggressiveness, restlessness, significant weight reduction and markedly elevated androgen levels. It has been suggested that musth-related behaviours are costly and that therefore musth may represent a form of physiological stress. In order to provide data on this largely unanswered question, the first aim of this study was to evaluate different assays for non-invasive assessment of adrenocortical function in the male African elephant by (i) characterizing the metabolism and excretion of [3H]cortisol (3H-C) and [14C]testosterone (14C-T) and (ii) using this information to evaluate the specificity of four antibodies for determination of excreted cortisol metabolites, particularly with respect to possible cross-reactions with androgen metabolites, and to assess their biological validity using an ACTH challenge test. Based on the methodology established, the second objective was to provide data on fecal cortisol metabolite concentrations in bulls during the musth and non-musth condition. 3H-C (1 mCi) and 14C-T (100 microCi) were injected simultaneously into a 16 year old male and all urine and feces collected for 30 and 86 h, respectively. The majority (82%) of cortisol metabolites was excreted into the urine, whereas testosterone metabolites were mainly (57%) excreted into the feces. Almost all radioactive metabolites recovered from urine were conjugated (86% 3H-C and 97% 14C-T). In contrast, 86% and >99% of the 3H-C and 14C-T metabolites recovered from feces consisted of unconjugated forms. HPLC separations indicated the presence of various metabolites of cortisol in both urine and feces, with cortisol being abundant in hydrolysed urine, but virtually absent in feces. Although all antibodies measured substantial amounts of immunoreactivity after HPLC separation of peak radioactive samples and detected an increase in glucocorticoid output following the ACTH challenge, only two (in feces against 3alpha,11-oxo-cortisol metabolites, measured by an 11-oxo-etiocholanolone-EIA and in urine against cortisol, measured by a cortisol-EIA) did not show substantial cross-reactivity with excreted 14C-T metabolites and could provide an acceptable degree of specificity for reliable assessment of glucocorticoid output from urine and feces. Based on these findings, concentrations of immunoreactive 3alpha,11-oxo-cortisol metabolites were determined in weekly fecal samples collected from four adult bulls over periods of 11-20 months to examine whether musth is associated with increased adrenal activity. Results showed that in each male levels of these cortisol metabolites were not elevated during periods of musth, suggesting that in the African elephant musth is generally not associated with marked elevations in glucocorticoid output. Given the complex nature of musth and the variety of factors that are likely to influence its manifestation, it is clear, however, that further studies, particularly on free-ranging animals, are needed before a possible relationship between musth and adrenal function can be resolved. This study also clearly illustrates the potential problems associated with cross-reacting metabolites of gonadal steroids in EIAs measuring glucocorticoid metabolites. This has to be taken into account when selecting assays and interpreting results of glucocorticoid metabolite analysis, not only for studies in the elephant but also in other species.

Abstract: Play remains a mystery and adult play even more so. More typical of young stages in healthy individuals, it occurs rarely at adult stages but then more often in captive/domestic animals, which can imply spatial, social and/or feeding deprivations or restrictions that are challenging to welfare, than in animals living in natural conditions. Here, we tested the hypothesis that adult play may reflect altered welfare states and chronic stress in horses, in which, as in several species, play rarely occurs at adult stages in natural conditions. We observed the behaviour (in particular, social play) of riding school horses during occasional outings in a paddock and measured several stress indicators when these horses were in their individual home boxes. Our results revealed that (1) the number of horses and rates of adult play appeared very high compared to field report data and (2) most stress indicators measured differed between ‘players’ and ‘non-players’, revealing that most ‘playful’ animals were suffering from more chronic stress than ‘non-playful’ horses. Frequency of play behaviour correlated with a score of chronic stress. This first discovery of a relationship between adult play and altered welfare opens new lines of research that certainly deserves comparative studies in a variety of species.