Introductory Chapter: Applications of Stress Endocrinology in Wildlife Conservation and Livestock Science

Animals have contributed towards the progress of mankind in many ways such as through biomedicine, scientific research, domestication and farming, zoo animals and aquaculture [1–5]. The key concept of animal welfare underpins the quality of life of an animal while living under human management [6]. Animal welfare is a complex subject which takes into account the environmental and management factors that influence the physiological, behavioural and emotional (well-being or affective) state of animals [7, 8]. Animals such as elephants, dolphins, birds and dogs can display complex cognitive ability guided by processes such as perception, learning, memory and decisionmaking [9, 10]. Emotion in animals involves complex physiological, behavioural, immune, cognitive and morphological responses that enable them to generate behaviours to cope against stressors [11]. There are specific physiological markers of pain and stress that enable researchers to evaluate the welfare of animals from a quantitative viewpoint and relate the data to understand how the animal perceives its environment [12, 13]

A Review on the Influence of Climate Change on Sheep Reproduction

Increasing food and natural fibre production ensure food security for nearly 10 billion people, the projected global population in 2050, without causing further environmental damage can be achieved by transforming systems and adopting sustainable agriculture practices within a changing climate. Globally, climate change effects are having both direct and indirect effects on agricultural productivity including changing rainfall patterns, drought, flooding and the geographical redistribution of pests and diseases. Climate change induced heat stress is thus one of the complex factors making sheep management and husbandry challenging in many geographical locations in the world. Within the sheep industry, reproductive wastage (RW) is a major challenge throughout the varying breeding landscapes. Reproductive wastage is defined as the early losses of embryos undergoing natural and/or artificial breeding programs. Our previous research showed that heat stress (THI > 75) and elevated glucocorticoid levels (indexed using faecal glucocorticoid metabolites) are linked to embryo loss in Merino ewes. This mini review discusses how extreme variation in climate such as heat stress affects the maternal reproductive performance in the Merino sheep and the impacts on the wool industry. We provide recommendations to sheep producers for monitoring and managing the effects of heat stress on-farm

Conservation Physiology of Tigers in Zoos: Integrating Stress Physiology and Behaviour to Monitor Their Health and Welfare

Big cats in zoos can face challenges associated with captive environments such as inadequate biological adaptation, increased occurrence abnormal behaviour and health-related problems. Conservation physiology is an emerging theme and a dynamic field of research, which aims to reduce these challenges of big cats captive management programmes through new scientific research integrating physiology and behaviour. This field of research applies cutting-edge physiological tools (e.g. non-invasive reproductive and stress hormone monitoring) in combination with traditional methods of behaviour and veterinary health assessments to provide a holistic account of how big cats respond to the captive environment. This book chapter discusses the applications of conservation physiology tools in the captive management of tigers in zoos. Our goal is to bolster tiger captive management in zoos by studying their stress physiology. Overall, the application of conservation physiology tools into captive management programmes for tigers and other big cat species can provide valuable information for evaluating and managing stress, thus improving tiger welfare

Physiological Stress in Rescued Wild Koalas Are Influenced by Habitat Demographics, Environmental Stressors, and Clinical Intervention

Koalas are rescued from the wild often with incidence of burns from bushfire, injury from animal attacks, vehicle collision, and diseases. Exposure to environmental stressors (trauma and disease) could generate physiological stress and potentially impact the outcomes of clinical management intervention and rehabilitation of rescued wild koalas. It is important to quantify the stress physiology of wild koalas upon registering into clinical care. This study demonstrates the first report of physiological stress assessment in rescued wild koalas (n = 22) to determine the potential influences of habitat-specific demographics, stressor category, and clinical diagnosis. Fecal samples were collected from the koalas at rescue and routinely during hospitalization to provide a longitudinal assessment of the koala's stress response throughout clinical care. Fecal glucocorticoid metabolites (FCM) enzyme-immunoassay was used to index physiological stress non-invasively. Koalas were admitted with exposure to various categories of environmental trauma such as vehicle collision, dog attack, burns from forest fire (this also related to conditions such as copious drinking and flat demeanor), and other injury. The main disease diagnosed was chlamydial infections. In terms of environmental interactions, it was found that habitat-specific demographics, location where the rescued koala was found, especially the rural-urban fringe, influenced FCM levels. Furthermore, there was significant interaction between location, stressor category, and clinical diagnosis for mean FCM levels. However, these factors were not predictive of the clinical outcome (euthanized or released). Overall, the results provide invaluable insights into how wild koalas respond physiologically to environmental trauma and disease and how methods of care, husbandry, and treatment can be used to further reduce the impacts of stress with the ultimate aim of increasing the rehabilitation and future release of rescued koalas to revive the declining mainland populations

Restrictive Type of Replication of Ovine/Caprine Lentiviruses in Ovine Fibroblast Cell Cultures

AbstractCaprine arthritis–encephalitis virus (CAEV) is a natural lentivirus pathogen of goats. CAEV, like all members of the ovine/caprine lentivirus family, has anin vivotropism for cells of the monocyte/macrophage cell lineage and activation of viral gene expression is observed only following differentiation of monocytes to macrophages. In addition to cells of the monocyte/macrophage lineage, CAEV and the closely related maedi visna virus of sheep (MVV) can also replicate productively in fibro-epithelial cells derived from synovial membrane of goats (GSM). However, these viruses varied greatly in their ability to replicate in fibroblasts. We studied the biological and biochemical properties of CAEV and maedi-visna virus (MVV) of sheep following inoculation into the three ovine/caprine cell types. Our data showed no substantial differences in virus titers, viral protein biosynthesis, or processing of the viral proteins between CAEV and MVV following inoculation into primary macrophages and GSM cells. However, unlike MVV, CAEV failed to replicate productively in ovine fibroblasts (sheep choroid plexus cells). This correlated with a specific but abnormal proteolytic cleavage of the envelope glycoprotein of the virus. This abnormal proteolytic cleavage represents a novel type of host cell restriction of lentivirus replication

Pre- and post-partum variation in wool cortisol and wool micron in Australian Merino ewe sheep (Ovis aries)

An individual merino sheep's output of wool production is influenced by synergistic interactions of sheep genetics, climate, farm management, and nutrition available to the whole flock. The price paid to the producer for this wool commodity is determined via numerous tested parameters and/or subjective appraisal of the raw greasy wool. This research investigated the level of variation in wool cortisol (a physiological stress biomarker) and wool micron (MIC) in Merino ewes (Ovis aries), pre-partum and post-lambing (lactation/lambs at foot), using maiden ewe (n = 38) managed in an outdoor paddock in a commercial farm. The key findings of this study are; (1) wool quality indicators showed a significant variation between pre- and post-parturition including significant reduction in MIC and (2) there was a negative correlation between wool cortisol levels and wool micron pre-parturition (rs = -0.179, p < 0.05). This relationship between wool cortisol and wool micron was positive (rs = +0.29, p < 0.05) during post-parturition suggesting that ewes with lambs at foot ended up with finer wool (reduction in fibre diameter) but they also maintained high levels of wool cortisol. Furthermore, the comfort factor, curvature, standard deviation and spin fineness of the wool were also significantly reduced post-parturition. The results of this study show that metabolic resources partitioning in ewe associated with pregnancy and lambing can result in a reduction in wool quality indices. The activity of the HPA-axis is attenuated during late gestation and parturition as a maternal adaptation; however, the results of our study show that wool cortisol remained similar between pre- and post-lambing. This result indicates that environmental stressors that may have been operating on farm (e.g., cold winter period) could influence on maternal physiological stress response however the exact level of influence of environment conditions on ewe stress levels and productivity traits (e.g., lambing success and wool quality) warrants further investigation. In conclusion, the use of top-knot wool sampling in combination with wool cortisol analysis provides researchers with a convenient method to quantify wool quality and physiological stress simultaneously under commercial sheep production

Developing Virtual Field Trips for Agriculture

Field trips play an important role in teaching and learning, from stimulating students’ motivations to allowing students to connect in-class concepts and the real world. Including field trips within an agricultural curriculum is essential as concepts are highly interdisciplinary, and knowledge application to a range of production systems and environments is critical. Despite their importance, many factors, such as high enrolments, present challenges to its successful integration. Virtual field trips (VFT) allow universities to leverage the affordances of technology to mitigate some of the associated challenges while maintaining quality course delivery. In this pilot study, an experiential learning activity was designed around a VFT application, and the student experience and outcome were investigated. The student experience measures indicated satisfaction with multimedia elements, although it is noted that improvements to the user interface would enhance the experience. Students had positive reflections on the learning experience, including an increased interest in the field of study but did not see VFTs as replacing actual field trips. Paired t-tests showed students’ attainment of learning outcomes. This pilot implementation provides an activity design for other courses with similar challenges and highlights the value of VFTs to the curriculum for undergraduate agricultural courses

Absolute Magnitudes and Colors of RR Lyrae stars in DECam Passbands from Photometry of the Globular Cluster M5

We characterize the absolute magnitudes and colors of RR Lyrae stars in the globular cluster M5 in the ugriz filter system of the Dark Energy Camera (DECam). We provide empirical Period-Luminosity (P-L) relationships in all 5 bands based on 47 RR Lyrae stars of the type ab and 14 stars of the type c. The P-L relationships were found to be better constrained for the fundamental mode RR Lyrae stars in the riz passbands, with dispersion of 0.03, 0.02 and 0.02 magnitudes, respectively. The dispersion of the color at minimum light was found to be small, supporting the use of this parameter as a means to obtain accurate interstellar extinctions along the line of sight up to the distance of the RR Lyrae star. We found a trend of color at minimum light with pulsational period that, if taken into account, brings the dispersion in color at minimum light to < 0.016 magnitudes for the (r-i), (i-z), and (r-z) colors. These calibrations will be very useful for using RR Lyrae stars from DECam observations as both standard candles for distance determinations and color standards for reddening measurements.Comment: Accepted for publication in A