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1.
C A Toerien R Puchala J P McCann T Sahlu A L Goetsch 《Journal of animal science》1999,77(6):1558-1564
Angora goats do not cope well with stress compared with goats of other breeds. Our hypothesis that this involves subclinical primary hypoadrenocorticism associated with low cortisol release in response to ACTH stimulation was tested by measuring adrenocortical response (plasma cortisol) in six Spanish (37 +/- 2 kg BW) and six Angora wethers (39 +/- 3 kg BW) under simulated acute and chronic ACTH challenges. In Exp. 1 (acute ACTH challenge), wethers were dosed i.v. with high (2.5 IU/kg BW) or low (.4 IU/kg BW) quantities of ACTH. In Exp. 2 (chronic ACTH challenge), ACTH at the rate of .015 IU/(kg BW x min) or saline (.15 M NaCl) was infused i.v. at 15 mL/h for 6 h. The mean baseline plasma cortisol concentration before ACTH stimulation was similar (P > .05) between Angora and Spanish goats in Exp. 1 (averaged over days) and in Exp. 2. The cortisol concentration response area (ng/ (mL x min) x 10(-3)) above the baseline was similar (P > .05) between Angora and Spanish goats during low (7.6 +/- .5 and 9.0 +/- 1.7, respectively) and high (12.8 +/- 1.0 and 16.0 +/- 1.8, respectively) levels of acute ACTH challenge (Exp. 1) and during chronic ACTH challenge (45.1 +/- 5.9 and 41.8 +/- 7.3, respectively; Exp. 2). In conclusion, these data indicate that, under the conditions of this study, adrenocortical responsiveness to ACTH stimulation is not different between Angora and Spanish goat wethers and, thus, may not contribute to stress susceptibility in Angora goats. 相似文献
2.
Geary TW 《Journal of animal science》2012,90(1):207-211
Pregnancy loss in beef cattle after d 28 of gestation is variable, but it has been reported to be as great as 14% and has been related to transportation or handling stress. The primary objective of this study was to determine whether activation of the hypophyseal-adrenal axis with ACTH would mimic a stressful response and cause pregnancy loss in beef cattle. A secondary objective was to determine if a single injection of the PG synthesis inhibitor flunixin meglumine would attenuate the stress response and suppress serum PGF(2α) concentrations to prevent pregnancy loss. Forty nonlactating beef cows that were 34 ± 0.33 d pregnant were used for this study. In a 2 × 3 factorial arrangement, cows were randomly assigned to receive ACTH [0 or 0.5 IU/kg of BW, intramuscularly (i.m.)] at 0 and 2 h of the study and flunixin meglumine (0, 1.1, or 2.2 mg/kg of BW, i.m.) at 0 h. Blood samples were collected from all cows at 0 h and every 30 min for 4 h to measure serum cortisol and PGF(2α) metabolite (PGFM) concentrations. Rectal temperature was collected for each cow at 0, 120, and 240 min. Pregnancy exams were conducted 31 and 58 d after treatment by transrectal ultrasonography, and the presence of a fetal heartbeat was used as an indicator of fetal viability. Serum cortisol concentration was affected (P < 0.01) by ACTH, time, and the interaction of ACTH × time, but not by flunixin meglumine (P ≥ 0.14) or any other interactions. Cortisol concentrations increased (P < 0.01) in the serum of ACTH-treated cows immediately after ACTH treatment and remained increased (P < 0.01) throughout the 4-h sampling period. Serum PGFM concentration was not affected by ACTH (P = 0.97) or by any interactions (P > 0.35) with ACTH, but was affected (P < 0.01) by flunixin meglumine, time, and the interaction of flunixin meglumine × time. Regardless of dosage (1.1 or 2.2 mg/kg of BW), flunixin meglumine decreased (P < 0.01) serum PGFM concentrations in both ACTH-treated and control cows for the duration of the study. Although ACTH treatment induced a prolonged increase in serum cortisol concentration, none of the cows used in this study lost a pregnancy. In conclusion, the activation of the hypophyseal-adrenal axis with ACTH increased serum cortisol concentrations but did not increase serum concentrations of PGFM or cause pregnancy loss during early gestation in cows. Flunixin meglumine treatment suppressed serum PGFM concentrations in control and ACTH-treated cows. 相似文献
3.
Graded levels of hydrocortisone 21-acetate (HYD) (0, 18, 16 and 24 mg/kg BW) were injected into nursing piglets every other day (Exp. 1) or 24 mg of HYD/kg BW was administered 0, 2, 4 or 6 times during the treatment period (12 d) with equal time (6 d, 3 d or 2 d) between subsequent injections (Exp. 2). Adrenocorticotropic hormone (ACTH) was injected to provide 0, 5, 10 or 15 IU/kg BW (Exp. 3), or 15 IU ACTH/kg BW was injected 0, 1, 2 or 3 times (Exp. 4). The injection treatment periods were from d 14 to d 26 postpartum. Pancreatic and intestinal amylase activity was maximized by the highest dosage of HYD (24 mg) and ACTH (15 IU) when given at 2- or 4-d intervals, respectively (P less than .10). However, four injections of HYD administered 3 d apart optimized the activity of this enzyme in Exp. 2 (P less than .05). Intestinal sucrase and maltase were unresponsive to ACTH regardless of dosage or injection frequency (P greater than .10). The response of these two enzymes to HYD was inconsistent. Maltase activity was elevated (P less than .10) by the two most frequent injection treatments, and sucrase activity was simultaneously depressed. Lactase activity tended (P less than .15) to be depressed by the highest treatment level in all four experiments. Both dosage and frequency methods of increasing HYD administration resulted in hepatic and pancreatic hypertrophy.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
4.
The effect of adrenocorticotropin hormone (ACTH) on plasma cortisol and on gonadotropin releasing hormone (GnRH)-induced release of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone was determined in nine Holstein bulls and 12 Holstein steers. Treatments consisted of animals receiving either GnRH (200 micrograms, Group G), ACTH (.45 IU/kg BW, Group A) or a combination of ACTH followed 2 h later by GnRH (Group AG). Group G steers and bulls had elevated plasma LH and FSH within .5 h after GnRH injection and plasma testosterone was increased by 1 h after GnRH injection in bulls. In Group A, plasma cortisol was elevated by .5 h after ACTH injection in both steers and bulls, but plasma LH and FSH were unaffected. In Group A bulls, testosterone was reduced after ACTH injection. In Group AG, ACTH caused an immediate increase in plasma cortisol in both steers and bulls, but did not affect the increase in either plasma LH or FSH in response to GnRH in steers. In Group AG bulls, ACTH did not prevent an increase in either plasma LH, FSH or testosterone in response to GnRH compared with basal concentrations. However, magnitude of systemic FSH response was reduced compared with response in Group G bulls, but plasma LH and testosterone were not reduced. The results indicate that ACTH caused an increase in plasma cortisol, but did not adversely affect LH or FSH response to GnRH in steers and bulls. Further, while testosterone was decreased after ACTH alone, neither ACTH nor resulting increased plasma cortisol resulted in decreased testosterone production in the bull after GnRH stimulation. 相似文献
5.
Serum cortisol and antigen-specific and polyclonal immunoglobulin G (IgG) concentrations were measured to investigate the relationship between vitamin A status and immune function in lambs. Twenty-four 3-mo-old crossbred ewe lambs weighing approximately 10 kg were each fed 900 g/d of a carotene-deficient diet. The 12 control lambs also received a 100,000 IU oral dose of vitamin A palmitate every 2 wk. All lambs were given primary and secondary antigenic challenges. Lambs were slaughtered at the end of the secondary challenge period. Liver vitamin A concentrations were greater (P less than .001) in the control animals (69.5 vs 1.3 micrograms/g wet tissue). Both groups of lambs exhibited a similar growth response until d 105, after which daily gain of the control lambs exceeded (P less than .03) that of the A-deficient lambs. Polyclonal serum IgG concentrations were greater (P less than .05) in the A-deficient lambs on d 49 to 124 and on d 151 (P less than .10). Ovalbumin-specific serum IgG concentrations tended to be greater in the control lambs throughout the primary and secondary challenge periods. Control lambs had greater titers on d 164 (P less than .07) and d 190 (P less than .03). Vitamin A status appeared to have no consistent effects on serum cortisol concentrations. Spleen weights were greater (P less than .002) in the A-deficient lambs. Lungs from 11 of 12 A-deficient lambs contained abscesses, as opposed to 1 of 12 for the control lambs. Both polyclonal and antigen-specific IgG concentrations were affected by vitamin A status. Serum cortisol concentrations did not appear to mediate this effect. 相似文献
6.
Recommendations for transportation of lambs, horses, calves, and pigs from a committee of the European Commission, which required rest stops of 6 or 24 h, every 8 h, were evaluated using Rambouillet x Suffolk lambs. The lambs of 17.6 +/- 0.5 kg of BW were randomly assigned to 1 of 3 treatments: transported for 22 h (continuous; n = 15); transported for 8 h, unloaded and rested for 6 h, transported for 8 h, unloaded and rested for 24 h, transported for 6 h (rested, n = 15); or remained in the home pasture throughout the study (control, n = 16). Off-trailer rest with food and water occurred in novel pens. Food deprivation in the continuous lambs was reflected by a decrease (P < 0.001) in plasma concentrations of glucose and an increase (P < 0.02) in plasma concentrations of blood urea nitrogen, creatinine, and total bilirubin relative to rested or control lambs. Electrolytes varied within and among all 3 treatments (P < 0.05), but no distinct pattern indicating dehydration was evident. Serum concentrations of cortisol were elevated in continuous and rested lambs compared with control lambs at 22 h (P < 0.05). Plasma immunoglobulin G antibody response to ovalbumin was suppressed (P < 0.05) in the continuous and rested lambs relative to the control lambs. Differences (P < 0.05) between continuous and rested lambs indicated the rest stops were sufficient to maintain BW during transport; however, these results were confounded by the control lambs losing a similar (P = 0.50) percentage of their initial BW as the continuous lambs at 22 h. The rest stops eliminated the physiological indicators of food deprivation and maintained BW but did not alleviate evidence of immunosuppression, and 52 h was required to complete the otherwise 22-h-long trip. 相似文献
7.
The effects of hemi-castration upon compensatory hypertrophy, serum gonadotropin and testosterone concentrations, testicular gonadotropin receptors and daily sperm production (DSP) were studied in 10 crossbred ram lambs. At 4 mo of age lambs were either hemi-castrated (HC; n = 5) or left intact (INT; n = 5). Blood samples were collected every 2 h for the first 24 h post-surgery, every 6 h for the next 24 h and then three times weekly for the following 14 wk. Serial blood samples (15-min intervals for 8 h) were collected during the 4th, 8th and 12th week following hemi-castration. Individual mean testicular and epididymal weights increased (P less than .05) 48 and 33% in HC compared with INT rams, respectively. Serum follicle stimulating hormone (FSH) increased (P less than .05) within 8 h after HC, reached peak concentrations within 1 wk and remained elevated for 4 wk before returning to concentrations of INT rams. Neither mean serum luteinizing hormone (LH) nor pulse patterns of LH or FSH were different (P greater than .05) between these two groups at any period examined. Serum testosterone (T) concentrations were lower (P less than .05) during the first 48 h post-surgery in HC rams, but by 1 wk concentrations were similar (P greater than .05) to those in INT rams. Remaining testes from HC and INT rams were removed at 7 mo of age, 3 mo after initial gonadal manipulation. On a per-testis basis there were more (P less than .05) LH and FSH receptors in HC than INT rams, respectively; however, concentrations of receptors were not different (P greater than .05).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
8.
Lambs were used to evaluate the effect of acute heat stress (HS) or restraint and isolation stress (RIS) on endocrinological and immunological functions. In Exp. 1, lambs were exposed to HS (35 degrees C) and control lambs (CN) were exposed to 21 degrees C for 24 h in two replicates (n = 8 lambs total per treatment). Samples of serum were obtained at frequent intervals for evaluation of cortisol; whole blood was obtained for total and differential leukocyte numbers and lymphocyte blastogenic function. The time-trends for cortisol between HS and CN lambs were different following treatment (P less than .005), but neither leukocyte numbers nor lymphocyte blastogenesis in response to mitogens were affected by acute exposure to the elevated ambient temperature. In Exp. 2, lambs (n = 6 per treatment) were given a 6-h RIS treatment and control lambs remained in their home stanchions (CON). Plasma and serum were obtained frequently during treatment and continued until 24 h after the onset of treatment. Plasma was evaluated for adrenocorticotropic hormone (ACTH) and serum was assayed for cortisol. Samples of whole blood also were obtained before and at 6, 12 and 24 h after the onset of treatment for determination of total and differential leukocyte numbers and lymphocyte blastogenic responses to mitogens. Both ACTH and cortisol were elevated in response to RIS; the profiles of these hormones over the 24-h bleeding period differed for RIS and CON lambs (P less than .001).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
9.
Gastrointestinal nematode infections cause substantial economic losses in pasture-based sheep farming worldwide. Host nutritional status has been identified as a key component of immune function. While vitamin E supplementation is known to have broad-spectrum effects on immune function in livestock, to our knowledge, there are no reports on the effect of vitamin E supplementation on trichostrongylid parasite infections in lambs. This study evaluated the effect of parenteral vitamin E supplementation on naturally acquired parasite infection in lambs. Twenty-seven spring lambs were sequentially assigned to receive injections of vitamin E (15 or 30 IU D-α-tocopherol/kg body weight (BW) or placebo, every two weeks, from birth to 28 weeks of age. Blood was collected at weeks 0, 2, 4, 8, 12, 16, 20, 24, and 28 to determine serum α-tocopherol concentration. Once the youngest animal reached 15 weeks of age all lambs were dewormed and grazed together on a pasture known to be contaminated with trichostrongylid larvae. Fecal egg count and blood packed cell volume (%) were determined on each lamb immediately prior to deworming and for the first seven weeks of pasture infection. Lambs were euthanized when they reached 28 weeks of age for determination of parasite worm burdens. Vitamin E supplementation at 30 IU/kg BW increased serum α-tocopherol over that of placebo (P<0.001) however, there was no effect of vitamin E supplementation on liver (P=0.804) or muscle (P=0.16) α-tocopherol content. There was no effect of vitamin E supplementation on fecal egg counts, packed cell volume, worm burden or nematode species distribution. Nematode genera identified were Haemonchus (30%), Trichostrongylus (42%), Nematodirus (27%), Strongyloides sp. (<1%), and Aonchotheca sp. (<1%). These results indicate that biweekly injections of vitamin E at 15 and 30 IU d-α-tocopherol/kg BW, had no effect on parasitological parameters used in the study to assess gastrointestinal nematode infection. 相似文献
10.
1. The high sensitivity of the immature domestic fowl to corticotrophin (ACTH) has been confirmed. The minimal effective dose was age-dependent, and decreased from 2 IU/kg BW in 1-d-old chicks to 0.4 IU/kg BW in 12-d-old chicks. 2. Increasing doses of ACTH evoked similar maximal corticosterone responses but the time to return to basal values increased with increasing dose of ACTH in both a broiler and layer strain. 3. Maximal corticosterone responses to ACTH occurred earlier in hatched chicks compared with embryos, and were delayed in embryos and young chicks of the layer strain compared to those of the broiler strain. 4. Strain differences in basal concentrations of corticosterone as well as in the response to ACTH occurred at a time when there were differences in the corticosterone content of the adrenals. 相似文献
11.
Crossbred ewe and wether lambs were used to evaluate the effects of a normal, nocturnal elevation in the concentration of melatonin in the serum on immunological functions. The nocturnal elevation in melatonin was eliminated by exposing half the lambs to constant light (LL), whereas the remainder received a 12-h light, 12-h dark cycle (LD). Immune function was challenged by treating half the lambs in LL and half of the lambs in LD with dexamethasone (DEX; .04 mg/kg); the remainder of the lambs received only a saline vehicle (SAL). The resulting treatment combinations were designated LD+SAL (n = 5), LD+DEX (n = 5), LL+SAL (n = 5), and LL+DEX (n = 5). Lambs were stanchioned individually in environmental rooms; photoperiod treatments commenced on that day (d -14). Also on d -14, lambs were given 1 mg ovalbumin/lamb in adjuvant. Lambs were given a booster injection of .5 mg ovalbumin/lamb on d 0. Treatments with DEX and SAL also began on d 0 and were repeated every 48 h through d 14. Catheters were placed in the jugular vein of all lambs on d 12; samples of plasma and serum were collected hourly from 0800 on d 14 to 0800 on d 15; plasma was assayed for adrenocorticotropic hormone (ACTH) and serum was assayed for cortisol and melatonin. In addition, samples of serum obtained at 0800 on d 15 were used to evaluate antibody titers to ovalbumin. Samples of whole blood also were obtained at 0800 on d 15, and total and differential leukocyte numbers and production of interleukin-2 (IL-2) by lymphocytes were determined.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
12.
Two Atlantic bottlenose dolphins (Tursiops truncatus) were given 0.11 mg/kg dexamethasone p.o., and complete blood count and serum chemistry analyses, including insulin, thyroxine (T4) adrenocorticotrophic hormone (ACTH), and cortisol level determinations, were performed at 0 hr, 24 hr, 36 hr, 48 hr, 7 days, and 17 days. Significant changes included neutrophilia, eosinopenia, lymphopenia, elevated insulin, and depressed ACTH and cortisol levels within 24 hr of dexamethasone administration. These effects were rapid, and values returned to normal within 48 hr. 相似文献
13.
Objective To determine the effectiveness of a topical anaesthetic formulation (Tri-Solfen) with or without the administration of a non-steroidal anti-inflammatory drug (carprofen) on the pain and distress response associated with ring or surgical castration of ram lambs.
Procedures Merino ram lambs (n = 78) were allocated to 10 treatment groups: 4 groups of knife-castrated lambs and 4 groups of ring-castrated lambs received carprofen (4 mg/kg SC) and Tri-Solfen; 2 control groups (sham) received carprofen at 0 or 4 mg/kg SC. Measurements included plasma cortisol and haptoglobin concentrations, haematology, and behaviour, including posture.
Results Knife-castrated lambs had higher peak cortisol and integrated cortisol responses for the first 6 h after treatment and greater concentration s of circulating acute phase proteins than ring-castrated lambs, both of which were significantly different from the sham controls. Tri-Solfen applied to the knife castration wound significantly reduced both the peak plasma cortisol concentration and the integrated cortisol response for the first 6 h and improved lying behaviour in the first 12 h. Carprofen reduced the cortisol response to knife castration at 30 min, but elevated the cortisol responses at 24 and 48 h. Carprofen nearly halved the number of acute pain behaviours associated with ring castration. There were no significant additive or synergistic effects from combining the analgesic treatments. Tri-Solfen applied to the tail wound provided no detectible benefits during ring castration + tail docking.
Conclusions The physiological and behavioural responses suggest that ring castration has less impact on the lamb than knife castration. The specific analgesic treatments can provide modest amelioration of the pain and discomfort associated with castration. Alternative doses or application methods may enhance their efficacy. 相似文献
Procedures Merino ram lambs (n = 78) were allocated to 10 treatment groups: 4 groups of knife-castrated lambs and 4 groups of ring-castrated lambs received carprofen (4 mg/kg SC) and Tri-Solfen; 2 control groups (sham) received carprofen at 0 or 4 mg/kg SC. Measurements included plasma cortisol and haptoglobin concentrations, haematology, and behaviour, including posture.
Results Knife-castrated lambs had higher peak cortisol and integrated cortisol responses for the first 6 h after treatment and greater concentration s of circulating acute phase proteins than ring-castrated lambs, both of which were significantly different from the sham controls. Tri-Solfen applied to the knife castration wound significantly reduced both the peak plasma cortisol concentration and the integrated cortisol response for the first 6 h and improved lying behaviour in the first 12 h. Carprofen reduced the cortisol response to knife castration at 30 min, but elevated the cortisol responses at 24 and 48 h. Carprofen nearly halved the number of acute pain behaviours associated with ring castration. There were no significant additive or synergistic effects from combining the analgesic treatments. Tri-Solfen applied to the tail wound provided no detectible benefits during ring castration + tail docking.
Conclusions The physiological and behavioural responses suggest that ring castration has less impact on the lamb than knife castration. The specific analgesic treatments can provide modest amelioration of the pain and discomfort associated with castration. Alternative doses or application methods may enhance their efficacy. 相似文献
14.
This study was conducted to examine serum cortisol concentrations and adrenal cortisol output in pigs treated chronically with recombinant pGH (rpGH) at a maximally effective anabolic dose. Recombinant pGH (140 micrograms/kg body weight) was administered daily to eight barrows for 77 d. At slaughter, adrenal glands were removed, weighed and sliced; slices of fresh adrenal tissue were incubated for 1 h in the presence or absence of ACTH. Recombinant pGH increased adrenal weight by 39%. This change was accompanied by an inversely proportional reduction of in vitro cortisol output per gram of tissue, with the net result that total cortisol output per adrenal per kilogram of BW was unaltered, as was cortisol output in the presence of ACTH. Serum cortisol concentrations were measured in 10 barrows fitted with femoral artery catheters and treated daily with 0 or 140 micrograms rpGH/kg BW for 8 d. Basal and ACTH-stimulated cortisol concentrations were not altered by rpGH treatment. These results do not support our earlier speculation that a pGH-dependent increase in adrenal weight is associated with a chronic increase in adrenal activity, but rather demonstrate that corticosteroid output is tightly regulated and remains constant despite a marked increase in the size of the adrenal glands. 相似文献
15.
Determination of the temporal relationship between porcine growth hormone, serum IGF-1 and cortisol concentrations in pigs 总被引：1，自引：0，他引：1
We found previously that porcine growth hormone (pGH) causes an increase in growth rate with a concurrent improvement in carcass composition in pigs. The somatomedin, insulin-like growth factor 1 (IGF-1), is though to play a major role in mediating some of the anabolic actions of GH, while the glucocorticoid hormones are potential counter-regulators of these effects. The present study was conducted to determine the temporal and dose-response relationship between GH administration and serum IGF-1 and cortisol concentrations in pigs. Twelve Yorkshire barrows, fitted with femoral artery catheters, were injected (im) with either 0, 10, 100 or 1,000 micrograms/kg pGH. Blood sampling began 40 min prior to pGH injection and was continued for 37 h. Serum GH, IGF-1 and cortisol concentrations were determined by radioimmunoassay. In control animals, serum GH concentrations ranged from 1.6 to 5.7 ng/ml over 37 h. In the animals treated with increasing doses of pGH, peak serum GH concentrations reached 28, 112 and 286 ng/ml and levels remained elevated for 4, 12 and 24 h, respectively. Serum IGF-1 concentrations were elevated by pGH after a lag time of 4 to 6 h. When the IGF-1 concentrations were integrated over time, the response appeared to be dose-dependent, with an ED50 of 710 micrograms/kg body weight (BW). Data for serum cortisol concentrations showed a great deal of individual variation. A transient increase in cortisol was observed, but only in the group treated with 1,000 micrograms pGH/kg BW. Cortisol levels returned to baseline 2 h after pGH injection.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
16.
The effect on water and electrolyte balance of stress, simulated by intravenous infusion of cortisol, was studied using 24 18-mo-old Merino wethers (37.0 +/- 0.94 kg mean body weight [BW]) over 72 h. The sheep were allocated to one of four groups: 1) no water/no cortisol (n = 6); 2) water/no cortisol (n = 4); 3) no water/cortisol (n = 6); and 4) water/cortisol (n = 4). Animals allocated to the two cortisol groups were given 0.1 mg x kg BW(-1) x h(-1) of hydrocortisone suspended in isotonic saline to simulate stress for the duration of the experiment. Total body water, plasma cortisol, osmolality and electrolytes, and urine electrolytes were determined at 24-h intervals for 72 h. In the presence of cortisol, total body water was maintained in the face of a water deprivation insult for 72 h. Water deprivation alone did not induce elevated plasma concentrations of cortisol, in spite of a 13% loss of total body water between 48 and 72 h. Infusion of cortisol was found to increase urine output (P = 0.003) and decrease total urinary sodium output (P = 0.032), but had no effect on plasma electrolyte levels or water intake. Water deprivation was found to increase plasma sodium concentrations (P = 0.037). These results indicate that sheep given cortisol to simulate stress suffer from a loss of body water in excess of that associated with a loss of electrolytes, and support the hypothesis that elevated physiological concentrations of cortisol induce a diuresis in ruminants that contributes to dehydration. 相似文献
17.
Rate of decline of cortisol concentrations in ovarian follicles following ACTH treatment in the sow. 
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下载免费PDF全文 A Montgomery M Viveiros E Cummings R Liptrap 《Canadian journal of veterinary research》1997,61(4):309-311
The rates of decline in cortisol concentrations in blood and ovarian follicular fluid were assessed in cyclic sows (n = 30) after treatment with saline or a depot form of adrenocorticotrophic hormone (ACTH). After a single injection of ACTH (0.5 iu/kg, BW, i.m.), peak cortisol values were achieved in blood within 3 to 4 h followed by a half-life net clearance rate (t1/2 of 2.40 +/- 0.29 (SE) h. The same dose of ACTH was then given at 12 h intervals from days 9 to 13 of the estrous cycle. On day 14 the concentrations of cortisol in follicular fluid were higher (P < 0.05) in ACTH-injected sows than in saline-injected controls. A t1/2 value of 37.81 h was determined for cortisol based on the decline in concentrations in follicular fluid collected on days 14, 16 and 18. This relatively slow rate of removal from developing ovarian follicles may have implications for the previously observed detrimental effects of increased cortisol concentrations on follicular development. 相似文献
18.
Objective To compare cortisol responses to three corticotrophic preparations in normal dogs.
Animals Eight clinically normal dogs (four intact males, four intact females) of medium size.
Procedures Each dog received four treatments on four separate occasions in a duplicated Latin square pattern. Treatments were two adrenocorticotrophin (ACTH) preparations given intramuscularly at 2.2 U/kg, one of the ACTH preparations given intramuscularly at 1 U/kg and a synthetic polypeptide with ACTH-like activity (tetracosactrin, cosyntropin) given intravenously at 5 μg/kg. Plasma samples were taken for cortisol assay before and at 0.5, 1, 2 and 4 h after treatment.
Results Plasma cortisol concentrations were similar with the two ACTH preparations and at both dose rates. Tetracosactrin produced smaller mean peak cortisol concentrations, which tended to occur earlier than with ACTH, and smaller values for the area under the curve of plasma cortisol concentration from zero time to 4 h.
Conclusion The findings suggest that canine adrenal function can be tested adequately by giving ACTH intramuscularly at 1 U/kg and measuring plasma cortisol in samples taken at 0 and 2 h, or by giving tetracosactrin intravenously at 5 μg/kg and determining cortisol concentration at 0 and 1 h. 相似文献
Animals Eight clinically normal dogs (four intact males, four intact females) of medium size.
Procedures Each dog received four treatments on four separate occasions in a duplicated Latin square pattern. Treatments were two adrenocorticotrophin (ACTH) preparations given intramuscularly at 2.2 U/kg, one of the ACTH preparations given intramuscularly at 1 U/kg and a synthetic polypeptide with ACTH-like activity (tetracosactrin, cosyntropin) given intravenously at 5 μg/kg. Plasma samples were taken for cortisol assay before and at 0.5, 1, 2 and 4 h after treatment.
Results Plasma cortisol concentrations were similar with the two ACTH preparations and at both dose rates. Tetracosactrin produced smaller mean peak cortisol concentrations, which tended to occur earlier than with ACTH, and smaller values for the area under the curve of plasma cortisol concentration from zero time to 4 h.
Conclusion The findings suggest that canine adrenal function can be tested adequately by giving ACTH intramuscularly at 1 U/kg and measuring plasma cortisol in samples taken at 0 and 2 h, or by giving tetracosactrin intravenously at 5 μg/kg and determining cortisol concentration at 0 and 1 h. 相似文献
19.
The objectives of this study were first to show adrenocortical response to a long‐acting adrenocorticotropic hormone preparation (tetracosactide acetate zinc suspension) (ACTH‐Z) and its effect on adrenocortical function in beef cows ( Experiment 1 ) and second to apply the ACTH‐Z challenge in dairy cows based on cortisol concentrations in milk collected at routine milking ( Experiment 2 ). In Experiment 1 , four beef cows in luteal phase were challenged with ACTH‐Z, and plasma cortisol concentrations were determined for 48 h after the injection at 30‐min to 2‐h intervals. A rapid ACTH test was conducted 3 days before and 2 h after the completion of ACTH‐Z injection for 48 h to investigate the effect on adrenocortical function. Plasma cortisol concentrations increased significantly 30 min after ACTH‐Z injection (p < 0.001), and the high cortisol levels were maintained for approximately 10 h after the injection. In Experiment 2 , eight dairy cows were subjected to ACTH‐Z challenge 1–2 weeks and 4–5 weeks post‐partum. Blood and milk samples were taken at morning and afternoon milking. All the cows showed a significant increase in cortisol concentrations in plasma as well as in skim milk 8 h after ACTH‐Z injection 1–2 weeks and 4–5 weeks post‐partum (p < 0.001). There was a significant correlation between plasma and skim milk cortisol concentrations 8 h after ACTH‐Z challenge (r = 0.74, p < 0.001). The results obtained in this study suggest that elevated levels of plasma cortisol are maintained for approximately 10 h after ACTH‐Z treatment without adverse effect on adrenocortical function and a long‐acting ACTH‐Z challenge based on cortisol concentrations in milk, which were collected at the morning and the afternoon milking, can be a useful tool to monitor adrenocortical function in cows. 相似文献
20.
Livestock grazing lush Kochia scoparia (L.) Schrad, sometimes experience BW loss, hyperbilirubinemia, photosensitization, and polyuria. Animals fed kochia hay may exhibit milder or negligible signs of toxicosis but fail to utilize nutrients efficiently. To characterize early aspects of kochia toxicosis and to evaluate prospective treatments, 12 wether lambs (34 +/- 3 kg) were fed prebloom kochia hay (83% OM, 15% CP, and 6.3% total oxalate) and treated as follows: 1) no treatment; 2) drenched daily with aqueous ZnSO4 to provide 30 mg of Zn/kg of BW); 3) injected i.p. twice weekly with N-acetyl-L-cysteine (CYS) in saline (21 mg/kg of BW) plus trans-stilbene oxide (TSO) in corn oil (27 mg/kg of BW); and 4) treated as 2) plus 3). Treatments were imposed factorially (2 x 2) with three lambs per treatment. Kochia intake (ad libitum) averaged .57 kg/d (1.7% of BW) for 80 d, and digestibility of DM and CP were 44 and 59%, respectively, at wk 4, but BW loss was severe (6 to 11 kg/lamb). After 14 d, serum insulin and prolactin were decreased (P less than .05) below initial values (.48 to .11 and 102 to 28 ng/ml, respectively). Serum somatotropin increased (P less than .05) from 4.5 to 6.8 ng/ml at 4 wk. Serum total bilirubin increased threefold at 3 wk (P less than .05) and declined slightly thereafter through 10 wk. Early changes in serum enzymes reflected mild hepatotoxicosis without cholestasis, whereas histopathology (at 80 d) showed diffuse hepatocyte swelling and nephrosis.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献