Basal and stress response cortisol levels and stress avoidance learning in sheep (Ovis ovis)

Basal and stress related corticosteroid levels show complex patterns of relationship to age, social status and aggressive behaviour ^{(1)(2)(3)(4)(6)}. I have investigated basal and stress related cortisol levels in sheep subjected to a model of learned stress avoidance, the results of which suggest that factors of stress avoidance learning ability and experience also contribute to cortisol levels.     

高新技术在饲料质量监测中的应用及发展

当前,安全和高质量食品的要求以及公司内部的质量安全分析的需求导致了饲料和食品的分析控制需求日益增加.随着产量、生产速度、市场竞争力的快速增长,需要更加快速、可靠的信息帮助生产商们做出合理的商业决策.……     

Effect of heat stress on oxidative stress, lipid peroxidation and some stress parameters in broilers

1. This study was conducted to determine the effects of heat stress on fearfulness, leucocyte components, oxidative stress and lipid peroxidation in two commercial broiler strains, Cobb (C) and Ross (R). 2. At 36 and 37 d of age birds were exposed to 38 +/- 1 degree C for 3 h. Rectal temperatures, duration of tonic immobility (TI), haematocrit values, proportions of leucocyte components (heterophil, lymphocyte, basophil, eosinophil, monocyte), malondialdehyde (MDA) concentrations and antioxidant enzyme activities (CAT, SOD, GPx) of all the birds were determined, before and after heat treatment. 3. Rectal temperatures increased and haematocrit values decreased in birds exposed to heat stress. Heat stress caused a significant increase in heterophil/lymphocyte and in basophil ratios. 4. Exposing birds to heat stress increased duration of TI, suggesting heat-stressed birds tended to be more fearful. 5. Heat stress resulted in a significant Genotype x Treatment interaction for MDA concentration. CAT, SOD and GPx activities; MDA concentrations in heat-stressed R strain birds were greater than in heat-stressed C strain birds.     

Workplace stress, mental health, and burnout of veterinarians in Australia

Objective To determine the frequency of the states of depression, anxiety, stress and burnout using internationally validated methods and to relate these to the demographic characteristics of veterinarians in Australia. Methods A postal survey of registered veterinarians with at least one year's experience and whose address was available; 1947 returned the questionnaire providing data for analysis. Results Overall, veterinarians describe higher levels of depression, anxiety, stress and burnout than the general population. The severity of these states was determined by gender, background, type of practice and years after graduation. Conclusions Modifying the curricula of veterinary schools to include the teaching of personal cognitive and coping skills to undergraduate veterinary students, the provision of the opportunity to enhance these skills throughout their veterinary career and changes in the veterinary workplace could result in improved mental health, increased job engagement and work satisfaction.     

水产养殖中的拥挤胁迫和操作胁迫

拥挤胁迫和操作胁迫是水产养殖中常见的胁迫现象,能引起鱼类内分泌、免疫和生理生化等一系列变化。维生素E、维生素C、磷脂以及n-3高不饱和脂肪酸(EPA、DHA)等营养元素可缓解这两种胁迫;MS-222、(异)丁子香酚等药物可减轻活体运输胁迫;此外,通过遗传育种手段和管理途径也能较好地控制拥挤胁迫和操作胁迫。     

Environmental stress and the physiology, performance and health of ruminants

A satisfactory environment is one that satisfies the following four criteria: thermal comfort, physical comfort, disease control and behavioral satisfaction. Environmental stress, which may be direct or indirect, is anything that departs from these criteria. Analysis of environmental stress is best achieved by the statistical approach, obtaining correlations from large numbers of animals in natural environments with the experimental approach, and a proper analysis of these correlations into probable causative effects. The amount of scientific attention devoted to thermal stress in ruminants has been very large, yet its practical importance compared, e.g., with environmental stress and disease is relatively small. The most important environmental stresses today are those that have resulted from housing and other attempts to ameliorate the thermal environment. These include air pollution, physical injuries from building surfaces and the extremes of confinement. The contribution of environmental stresses to injury and to diseases such as mastitis and calf pneumonia are discussed and schemes are proposed for future experiments designed to analyze interactions between environment and disease. Examples are also given of approaches to the analysis of the stress of behavioral deprivation.     

Dehydration, stress, and water consumption of horses during long-distance commercial transport

The aim of this study was to characterize progressive dehydration, stress responses, and water consumption patterns of horses transported long distances in hot weather and to estimate recovery time after 30 h of transport. Thirty adult mares and geldings were deprived of access to feed and water for 6 h, blocked by age, sex, breed, and body condition score, and assigned to one of the following treatments: penned, offered water (Penned/Watered, n = 5); penned, no water (Penned, n = 5); transported, offered water (Transported/Watered, two groups of n = 5); or transported, no water (Transported, two groups of n = 5). None of the horses had access to feed while on treatment. A commercial, single-deck, open-top, 15.8-m-long trailer was divided into four compartments to accommodate the two Transported/Watered and two Transported groups at 1.77 m2 per horse. At 8, 17, 22, 27, 30, and 33 h after initiation of transport, the truck returned and stopped for 1 h to allow for data collection and to give the Transported/Watered and Penned/Watered horses 10 min of access to water in individual buckets. Treatments for the non-watered horses (Penned and Transported) were terminated after 30 h due to dehydration and fatigue, whereas the watered horses (Penned/Watered and Transported/Watered) could continue for another 2 h. Mean weight loss after 30 h was greater in the Penned (57.1 kg, 12.8%) and Transported (52.2 kg, 10.3%) groups than in the Transported/Watered (20.7 kg, 4.0%) and Penned/Watered (17 kg, 3.5%) groups (P < 0.0001). Respiration, heart rate, sodium, chloride, total protein, and osmolality were significantly elevated in the non-watered horses (P < 0.0001), and sodium, chloride, total protein, and osmolality greatly exceeded normal reference ranges, indicating severe dehydration. Although not statistically significant, the horses penned in full sun, with or without water, had a dehydration response that was slightly greater than that of the transported horses. Plasma cortisol concentrations had a significant time x treatment interaction (P < 0.0001), in which the Penned/Watered and Transported/Watered horses remained relatively consistent, whereas the Transported, and especially the Penned, horses' plasma cortisol concentrations greatly increased. Transporting healthy horses for more than 24 h during hot weather and without water will cause severe dehydration; transport for more than 28 h even with periodic access to water will likely be harmful due to increasing fatigue.     

动物的应激、行为和钠需求之间的关系

1引言自然界的各种动物均时时刻刻面临着不同应激的挑战,这是很正常的。野生动物的应激来自于不停的寻找有限的食物或害怕变成捕食者的美餐。另外,炎热的天气和寒冷的气候,以及各群体之间的拮抗作用等均可构成应激。在本文中我们主要讨论由潜在的损害性刺激引起的畜禽应激反应与一些异常行为之间的关系。这种应激反应的范畴非常广泛,其中有相对无害的自舐行为,也有极端野蛮的互相伤残现象。在畜牧业实际生产中,我们采取各种手段来尽量减少畜禽的应激反应,这不仅有利于动物本身,而且也有利于生产者。各种应激将会增加动物正常的维持需求量,例…     

Effect of seasonal thermal stress on oxidative status,immune response and stress hormones of lactating dairy cows

This study aimed to assess the impact of seasonal thermal stress on oxidative stress, immune response, and stress hormones of lactating dairy cows in subtropical regions with different levels of temperature-humidity index (THI). A total of 32 healthy lactating Holstein dairy cows experienced 4 seasons (8 cows/season). The physiological parameters were categorized into low THI (LTHI, THI = 42.97 ± 0.95) in winter, moderate THI (MTHI, THI = 61.84 ± 0.42) in spring and autumn, and high THI period (HTHI, THI = 86.09 ± 0.23) in summer. The blood samples were collected twice in each season to measure oxidative stress, inflammatory and hormonal parameters. Our results showed THI had a positive correlation with the rectal temperature (R² = 0.821, P < 0.001) and respiratory rate (R² = 0.816, P < 0.001). Dry matter intake, milk yield and fat percentage also significantly differed among groups (P < 0.05). Compared with the MTHI group, the LTHI group exhibited a significant increase in malondialdehyde (MDA) level (P < 0.001), and the HTHI group displayed a significant increase in levels of cortisol, interleukin (IL)-10, IL-1β and tumor necrosis factor-α (P < 0.001). Opposite changes in serum endotoxin and immunoglobulin G levels were observed with the increasing THI (P < 0.001). LTHI notably increased the triiodothyronine level, although the thyroxine level was reduced by LTHI and HTHI compared with the MTHI group. In conclusion, LTHI and HTHI conditions may induce different degrees of oxidative stress, inflammation response, and stress hormone imbalances on lactating dairy cows, therefore environmental management is necessary for the health of dairy cows in extreme weather conditions.     

盐胁迫对金盏菊生长、抗氧化能力和盐胁迫蛋白的影响

用NaCl浓度为0(对照),10,50,100,200,300 mmol/L分别处理金盏菊,对不同盐浓度下金盏菊生长、抗氧化能力和盐胁迫蛋白的变化进行了研究。结果显示,在不同浓度NaCl胁迫下,与对照相比,金盏菊鲜重、干重、叶绿素含量、SOD和POD活性均呈先上升后下降趋势,而MDA含量呈先下降后上升趋势;Na⁺含量、细胞质膜透性呈上升趋势,而根系脱氢酶活性、K⁺含量、CAT活性则呈下降趋势。电泳结果显示,POD有8个谱带;10 mmol/L NaCl处理诱导盐胁迫蛋白产生,而其他浓度盐胁迫均无盐胁迫蛋白诱导产生。因此,10 mmol/L NaCl处理对金盏菊生长有一定促进作用,而随着NaCl浓度逐渐增加,其生长受抑制程度也逐渐加重。综合分析表明,金盏菊耐盐阈值为100 mmol/L。     

Thermophysiological,haematological, biochemical and behavioural stress responses of sheep transported on road

The study was conducted to evaluate the thermophysiological, haematological, biochemical and behavioural stress responses of sheep transported on road. A total of 44 Chamarita breed adult ewes were randomly allotted to one of two groups, one control group (untransported) and transported group (journey of 4 h), and blood stress indicators were measured 1 day before transport and at four time points post‐transport (0, 4 and 24 h). Thermophysiological profiles of ewes were measured by temperature buttons (iButton Thermochron^®) and placed in intravaginal sponges. Direct observations, with a combination of scan and behaviour sampling, were carried out to collect information on individual behaviour and the time it took the ewes to drink water, eat and rest after returning to their pen respectively. Transported ewes lost approximately 1 kg live weight compared to controls and had higher body temperatures until 12 h post‐transport. Cortisol, glucose, non‐esterified fatty acid (NEFA) concentrations as well as the neutrophil–lymphocyte ratio (N/L) and other physiological indicators were higher immediately after unloading in transported ewes but mostly returned to normal after 4 h, with complete recovery after 24 h. Behavioural analysis post‐transport demonstrated that transported ewes chose to eat before drinking and spent less time resting than controls in the first 3 h after unloading. The study demonstrates that transportation even under short‐journey conditions induced behavioural, physiological and thermophysiological responses indicative of the induction of significant stress, leading to live weight shrinkage that may jeopardize farmer's incomes. Finally, results of this study validated the use of iButton Thermochron^® data loggers for monitoring the stress response during transport.