Effect of different dietary energy levels on physio-biochemical,endocrine changes and mRNA expression profile of leptin in goat (Capra hircus)

This study aims to assess the effect of different energy levels of restriction on physiological and genetic level adaptability. Eighteen adult nonpregnant does (average BW 33.56 kg) were used in the present study. The ewes were divided into three groups, viz., GI (n=6; control), GII (n=6; 30% feed intake of control), GIII (n=6; 40% feed intake of control). The study was conducted for 40 days covering a period of two estrous cycles. Blood samples were collected every ten days interval. The parameters studied were allometric parameters (viz., body weight, and body condition) scoring and physiological responses (viz., respiration rate, pulse rate, and rectal temperature) biochemical parameters (glucose, albumin, creatinine, cholesterol), hormones (T3, T4, cortisol, leptin) and mRNA expression profile of leptin in peripheral blood mononuclear cells (PBMC). The nutritional stress significantly (P<0.05) affected most of the parameters. There was a significant (P<0.05) reduction in Body weight, Body condition score and. The physiological responses were significantly (P<0.05) affected. Among the biochemical parameters mean serum glucose first increased significantly (P<0.05) and then stabilized in GII whereas as there was no change in serum glucose levels in GIII. Serum albumin significantly (P<0.05) affected in late stages of study. There was no significant (P<0.05) changes in serum creatinine. Among hormonal parameters there was significant decrease in T3 in both the groups; T4 increased significantly in GII on 10th day and then stabilized whereas no changes was observed in GIII. Cortisol levels increased significantly (P<0.05) in both GII and GIII. There was a significant (P<0.05) reduction in serum leptin levels in GII but in GIII significant reduction was observed only 10th and 30th day of study. The mRNA expression was significantly (P<0.05) upregulated in GII on 30th day followed by a significant downregulation whereas in GIII significant (P<0.05) downregulation was only seen on 30th and 40th days. It can be concluded from our study that animals can maintain near physiological homeostasis even at 40% energy intake levels. The animals have innate physiological ability to survive periods of nutritional stress by adjusting leptin levels which are required for maintaining the physiological normalcy.     

On the relationships between glucocorticoids and feed efficiency in beef cattle

Improvement in the utilization of feed in livestock is an important target of breeding and nutritional programs. Recent evidence indicates a potential association between feed efficiency and fecal cortisol metabolites, which could eventually be used as an indirect assessment of this trait. This evidence is more comprehensively evaluated in here with samples for plasma cortisol (PC; ng/ml) and fecal cortisol metabolites (FCM; ng/ml) collected more often during the entire finishing phase in beef steers. Individual daily feed intake of 112 steers fed a high-moisture corn-based and haylage diet was measured over 168 d. Body weight, blood and fecal samples were collected every 14 d and ultrasound measures of backfat thickness and longissimus muscle area were taken every 28 d. Four productive performance traits were calculated: daily dry matter intake (DMI), average daily gain (ADG), feed to gain ratio (F:G) and residual feed intake (RFI). At the end of the feedlot phase, steers were ranked according to RFI and samples were analyzed for PC and FCM from the 32 steers with greatest and 32 steers with lowest feed efficiency. In addition, a sub-group of 12 steers from each of these two groups with divergent feed efficiency were subjected to hourly blood sampling for 24 h. Less efficient steers had greater DMI, F:G and consumed 1.5 kg/d more DMI (P<0.05) than steers with improved feed efficiency. No differences (P>0.10) in PC over the 12 biweekly sampling periods between steers with divergent feed efficiency were observed. However, a trend toward significance between 19:00 and 02:00 h over the hourly sampling evaluation was noticed, with the sub-group of more feed efficient steers presenting higher levels of PC in this period of the day (P=0.08). On the other hand, FCM levels displayed a distinct pattern between RFI groups over the biweekly sampling period, with more efficient cattle presenting greater levels of these metabolites (P<0.05). This study reinforces the positive association between improved feed efficiency and FCM levels over the finishing phase; and the lack of association between feed efficiency and PC when single samples are collected every two weeks through a single jugular venipuncture performed after handling the cattle for sampling. Further studies to develop sampling protocols for assessing FCM as an indicator trait for feed efficiency are warranted, as well as, studies to understand the role of endogenous glucocorticoids in the performance of the bovine.     

Circulating β-Endorphin,Adrenocorticotropin, and Cortisol Concentrations of Horses Before and After Competitive Show Jumping with Different Fence Heights

Circulating β-endorphin, adrenocorticotropin, and cortisol concentrations were studied before and after competitive show jumping in 18 trained jumper horses aged between 11 and 13 years and having the same level of show experience. Horses were subjected to the same type of management and daily training exercise. Each horse had been ridden by the same rider during both the daily training exercise and show jumping event. All horses, randomly divided into three groups paired by gender, performed in three competition levels with the same circuit design over 10 fences, with 5 upright and 5 cross-pole fences, differing for the fence height: group I (n = 6), 1.10 m; group II (n = 6), 1.20 m; and group III (n = 6), 1.30 m. Repeated measures analysis of variance showed a statistically significant effect of competitive exercise on β-endorphin and cortisol changes in all groups, whereas the effect of exercise on adrenocorticotropin changes was exclusively seen in groups II and III. Two-way repeated measures analysis of variance showed that the effect of fence height was significant (P = .03), and time (P = .0001) also affected cortisol changes. These results suggest that the hypothalamic-pituitary-adrenal axis response is different with respect to the different fence heights of jumping course and the different time points of the recovery period.     

Blood serum characteristics of newborn pigs: comparison of unaffected pigs with pigs belonging to five mortality groups.

The blood serum levels of glucose, hemoglobin, insulin, cortisol, albumin, alpha-fetoprotein, alpha 2-macroglobulin f and s, alpha 2-antitrypsin inhibitor and alpha 1-protease inhibitor were determined at birth in 5 clinically and morphologically identified mortality groups of pigs. These were compared with the levels observed in unaffected, apparently normal newborn unsuckled pigs. The blood serum profile of the pigs in the stillborn intra partum, weak, splayleg and trauma groups, respectively, as well as that of clinically normal splayleg littermates, differed significantly from that of the unaffected pigs. This was especially true for the levels of hemoglobin and the two macroglobulins. The importance of placental insufficiency causing chronic episodes of hypoxia which ultimately lead to a disturbance in organ development in the etiology of the mortality groups is discussed.     

The effect of mid-pregnancy stressors on twin-lamb live weight and body dimensions at birth

This study was conducted to determine the effect of crutching, simulated shearing and conventional shearing in mid-pregnancy on maternal plasma cortisol levels and lamb live weight and body dimensions at birth. Twin-bearing Romney ewes (n = 96) were subjected to one of four treatments (control, crutched, sham shorn and shorn) on day 80 of pregnancy. Ewes were maintained as a single flock throughout pregnancy under commercial farming conditions. Within 12 h of birth the lambs were weighed and their body dimensions recorded. Lambs born to ewes shorn in mid-pregnancy were heavier (P < 0.05) at birth than lambs born to control or sham-shorn ewes by 300 and 400 g (7 and 10%) respectively. The birth weight of lambs born to crutched and control ewes did not differ. Shearing and crutching produced a greater integrated cortisol response than sham-shearing (P < 0.05). The failure of crutching to increase lamb birth weight suggests that the acute stress caused by shearing does not result in increased lamb birth weights.     

Influence of aging on adrenal responsiveness in a population of eleven healthy beagles

The present study aimed at investigating the effects of aging on the adrenal cortex response of cortisol and aldosterone in dogs.A population of healthy adult Beagles was evaluated twice at a five-year interval. At each evaluation, plasma basal cortisol and aldosterone, cortisol and aldosterone following ACTH-stimulation, sodium, and potassium concentrations and arterial blood pressure were measured. We observed significantly (p < 0.05) greater sodium, urea and creatinine concentrations with aging. Nevertheless urea and creatinine remained within our laboratory reference ranges. This study showed a highly significant age-related elevation of basal cortisol (p < 0.01). Inversely, both aldosterone following ACTH-stimulation levels and difference between aldosterone following ACTH-stimulation and basal aldosterone values plummeted significantly (p < 0.01) with aging. In conclusion, the evaluation of the adrenal cortex function in dogs should take in consideration the age of the individuals.     

Whole-body concentrations of cortisol and sex steroids in white sturgeon (Acipenser transmontanus, Richardson 1836) during early development and stress response

In general little is known about hormones and the ontogeny of the stress response in the early developmental stages of chondrostean fishes and in particular of white sturgeon (Acipenser transmontanus, Richardson 1836). In this study, we measured for the first time cortisol and sex steroids (testosterone and estradiol) in eggs, larvae, post-larvae, and fry of white sturgeon by radioimmunoassay (RIA), to elucidate some endocrine aspects of its development. The cortisol, testosterone, and 17β-estradiol of maternal origin found in unfertilized eggs of white sturgeon probably regulate both growth and development of the embryo. Cortisol decreased after fertilization, whereas testosterone and 17β-estradiol did not significantly change. During the late stages of embryo development and immediately after hatching, endogenous production of cortisol and sexual steroids, respectively, occurred. Sex steroids may be physiological inducers of gonad sex differentiation in sturgeon. All steroids showed an increase 10 days post-hatch (dph), near the transition from an endogenous to an exogenous energy source. Cortisol maintained the same basal levels even after metamorphosis, whereas testosterone and 17β-estradiol declined significantly in post-larvae at 35 and 45 days post-hatch. In addition, to evaluate the ontogeny of a functional hypothalamic-pituitary-interrenal (HPI) axis, larvae and fry were submitted to acute stress. The HPI axis did not seem to be functional on the first day post-hatch, but became so from the third day post-hatch onward.     

运输密度和盐度对大黄鱼幼鱼皮质醇、糖元及乳酸含量的影响

为了确定大黄鱼运输的适宜条件,实验选取平均体质量为(0.12±0.03)g的大黄鱼幼鱼为实验对象,采取析因设计,设3个运输密度(2、4和8 g/L)和5个运输盐度(5、10、15、20和25),共计15个处理组研究了不同密度和盐度运输条件下,大黄鱼幼鱼皮质醇、糖元及乳酸含量的变化。经过水温16.5℃、10 h的运输,统计各组的死亡率,测定各组水中总氨氮含量。结果显示,在运输结束后,4和8 g/L密度组死亡率(1.33%、2.63%)显著高于2 g/L密度组(0.77%),盐度25组死亡率(0.44%)显著低于盐度10、15组(1.94%、1.67%),盐度10、15组死亡率显著低于盐度5组(2.72%),各组水中总氨氮含量较运输前(0.15 mg/L)均显著升高,各密度组水中总氨氮含量均有显著性差异,高密度组总氨氮含量高于低密度组,8 g/L密度条件下盐度5组水中总氨氮含量(1.63 mg/L)显著高于盐度15(1.38 mg/L)、盐度20(1.34 mg/L)和盐度25(1.31 mg/L)组,4 g/L密度条件下盐度5组水中总氨氮含量(1.31mg/L)显著高于其他各盐度组,2 g/L密度条件下盐度5组水中总氨氮含量(0.83 mg/L)显著高于盐度25组(0.49 mg/L);运输胁迫导致各组皮质醇含量均较运输前(6 476.35 ng/L)显著升高,各组间皮质醇含量无显著性差异;各组糖元含量均较运输前(4.37 mg/g prot)显著降低,运输后各组间糖元含量无显著性差异;各组乳酸含量均较运输前(0.57 mmol/g prot)显著升高,运输后各密度组间乳酸含量无显著性差异,3个密度下盐度5组乳酸含量(1.91、2.02、1.76 mmol/g prot)均显著高于盐度20(1.55、1.21、1.69 mmol/g prot)和盐度25组(1.36、1.44、1.26 mmol/g prot),盐度10组乳酸含量(1.77、1.83、1.60 mmol/g prot)显著高于盐度25组(1.36、1.44、1.26 mmol/g prot)。研究表明,较高的运输密度和较低的盐度会加重大黄鱼的应激性反应,在本实验条件下,规格为0.1 g左右的大黄鱼幼鱼,其运输密度不宜超过8g/L,盐度不宜低于5。     

The acute stress response in fed and food deprived Atlantic cod, Gadus morhua L.

The aim of the present study was to evaluate the effect of stress and nutritional state (fed vs food deprived) on the generalized stress response and intestinal integrity in Atlantic cod (Gadus morhua L.). Cod in feeding or food deprived states were subjected to 15 min of acute stress (exhaustive exercise). Blood was collected at 9 intervals from before stress (t = 0), to t = 48 h post stress and analysed for blood haematocrit and haemoglobin, and plasma cortisol, lactate, glucose, osmolality, chloride, as well as the tissue damage indicators glutamate oxaloacetate transaminase, glutamate pyruvate transaminase and thiobarbituric acid reactive substances. Intestinal segments were prepared for histology with the same intervals, while assessment of intestinal integrity and microbiology was performed at t = 0, 4 and 48 h post stress.Subjecting cod to exhaustive stress initiated a standard stress response including increased blood Hct and plasma cortisol, glucose, chloride, osmolality and lactate. Food deprived fish did in general have reduced stress resistance compared to fed fish. For many parameters, cod returned slowly to basal levels. Cellular indicators of tissue damage and oxidative stress increased in a biphasic manner following stress. Stress did not affect gut histology but did transiently increase gut permeability. Furthermore, stress had no effect on the adherent bacterial population level in midgut, but did cause a small decrease in hindgut (non-significant) and hindgut chamber (p < 0.05). Isolates belonging to Carnobacterium were predominant but not affected by stress.In conclusion, food deprived cod are less resistant to stress than fed cod. The magnitude of the response is less than in salmonids, but the effects are persistent (including tissue damage indicators and oxidative stress) and may have negative long term consequences. The gut is relatively resistant to stress, there is however a transient increase in the intestinal permeability and alterations in microbiota that may indicate lower protection against invading pathogens.