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1.
This study evaluated anesthesia quality, degree of analgesia and cardiorespiratory parameters after intramuscular (IM) injection of a combination of butorphanol (0.1 mg/kg), medetomidine (10 µg/kg) and alfaxalone (1.5 mg/kg) in ten healthy adult Beagle dogs. Rectal temperature (T), heart rate (HR), respiratory rate (fR), arterial pressure, arterial blood gases and M-mode echocardiographic left ventricular (LV) indices were measured before drug administration and every 10 min thereafter until extubation. Mean duration of anesthesia, recovery and analgesia were 89 ± 17, 6 ± 1 and 80 ± 12 min. HR, fR, partial pressure of arterial CO2 and O2, arterial pressure, and LV contractility were significantly altered during anesthesia. IM administration of the drug combination provided acceptable anesthesia, but produced substantial cardiorespiratory suppression.  相似文献   

2.
For this study, 2 experiments were conducted to evaluate the effects of dietary BioPlus 2B® supplements on growing pigs. In experiment 1, 64 crossbred pigs (26.70 ± 0.50 kg) were subjected to a 35-day feeding trial (2 pigs/pen, 8 pens/treatment) in which the effects of the following four corn-soybean meal based dietary treatments were compared: 1) CON (basal diet); 2) B0.05 (basal diet + 0.05% BioPlus 2B®); 3) B0.1 (basal diet + 0.1% BioPlus 2B®) and 4) B0.2 (basal diet + 0.2% BioPlus 2B®). During the experimental period, average daily gain (ADG) tended to increase in a linear fashion (P = 0.08) with increasing levels of dietary BioPlus 2B®. In addition, the average daily feed intake (ADFI) was found to increase (P < 0.05) as the levels of BioPlus 2B® increased. However, no linear or quadratic effects were observed in the gain:feed ratio (G:F) or in the coefficients of total tract apparent digestibility (CTTAD) when dry matter (DM) and nitrogen (N) were considered. In experiment 2, 16 crossbred barrows (25.60 ± 0.10 kg) were randomly allotted to 1 of the 4 dietary treatments used in experiment 1 (1 pig/pen, 4 pens/treatment). The noxious gas emissions and pH of slurry waste were then measured daily for 120 h. Ammonia (NH3) emission from the slurry samples obtained from pigs in the BioPlus 2B® groups was lower than that of slurry obtained from pigs in the CON treatment (P < 0.05), however, hydrogen sulfide (H2S) and mercaptan emission were not affected by supplementation with BioPlus 2B®. In addition, the pH value decreased with time, and the pH values of slurry obtained from pigs subjected to the B0.1 and B0.2 treatments were lower than those of samples obtained from other groups after 48 h (P < 0.05). Taken together, these results indicate that supplementation with BioPlus 2B® can reduce slurry NH3 emission, but not H2S and mercaptan emission in growing pigs without impacting growth performance.  相似文献   

3.
With a growing global population and increased environmental concerns around animal agriculture, it is essential to humanely maximize animal performance and reduce environmental emissions. This study aims to determine the efficacy of feeding ractopamine hydrochloride (RAC), an orally active, β 1-adrenergic agonist (β1AA), to feedlot steers in the last 42 d of finishing to reduce ammonia (NH3) emissions and improve animal performance. A randomized complete block design was used to allocate 112 Angus and crossbred Angus steers (initial body weight [BW] = 566.0 ± 10.4 kg) to 8 cattle pen enclosures. Pens (n = 4 per treatment, 14 steers per pen, and 56 steers per treatment) were randomly assigned to one of two treatments: 1) CON; finishing ration containing no RAC, 2) RAC; finishing ration containing 27.3 g/907 kg dry matter (DM) basis RAC. Steers were weighed on day −1 and 0 before treatment and day 14, 28, and 42 during treatment. Treatment rations were mixed and delivered daily by masked personnel. Measured emissions included NH3, nitrous oxide (N2O), methane (CH4), hydrogen sulfide (H2S), and carbon dioxide (CO2). The primary response variables assessed were emissions standardized by live weight (LW) and hot carcass weight (HCW). Steers were harvested on day 43 and carcass data were collected on day 43 and 44. Steers fed RAC reduced NH3 emissions by 17.21% from day 0 to 28 (P = 0.032) and tended to reduce NH3 from day 0 to 42 by 11.07% (P = 0.070) vs. CON. When standardized for LW, NH3 was reduced by 23.88% from day 0 to 14 (P = 0.018), 17.80% from day 0 to 28 (P = 0.006), and 12.50% for day 0 to 42 (P = 0.027) in steers fed RAC vs. CON. Steers fed RAC had 14.05% (P = 0.013) lower cumulative NH3 emissions when standardized by HCW vs. CON. Feeding RAC to Steers reduced H2S by 29.49% from day 0 to 14 (P = 0.009) and tended to reduce H2S over day 0 to 28 by 11.14% (P = 0.086) vs. CON. When H2S emissions were standardized for LW, RAC fed steers had a 28.81% reduction from day 0 to 14 (P = 0.008) vs. CON. From day 0 to 42 the RAC fed steers tended to have a 0.24 kg/d greater average daily gain (ADG) (P = 0.066) and tended to eat 4.27% less (P = 0.069) on a DM basis vs. CON. The RAC fed steers had a 19.95% greater gain to feed ratio (G:F) compared to CON (P = 0.012). Steers fed RAC had an average of 12.52 kg greater HCW (P = 0.006) and an increase of 1.93 percentage units in dressing percent (DP) (P = 0.004) vs. CON. Ractopamine is an effective medicated feed additive for reducing NH3 and improving end product performance through HCW yields.  相似文献   

4.
ObjectiveAtrial natriuretic peptide (ANP) and cardiac troponin I (cTnI) serve as biomarkers for increased cardiac pressure/volume loading and for myocardial stress or damage. The objective was to describe the time course of plasma ANP concentrations (CpANP) and plasma cTnI concentrations (CpcTnI) in horses with mitral regurgitation (MR) compared to healthy horses at rest and after exercise, and to describe the relationship of CpANP with cardiac dimensions and intracardiac pressures.Animals15 healthy Warmblood horses and 7 Warmblood horses with MR.MethodsCardiac dimensions at rest were measured using echocardiography. All horses underwent standardized treadmill exercise. Biomarker concentrations and intracardiac pressures were measured at rest and after exercise. Hypotheses were tested using statistical methods. The level of significance was P < 0.05.ResultsHorses with MR showed increased left atrial (LA) and left ventricular (LV) dimensions but similar exercise capacity compared to healthy horses. Pulmonary capillary wedge pressures (PCWP) and CpANP increased with exercise. Horses with MR had higher PCWP and higher CpANP at rest and after exercise compared to healthy horses, with the maximum difference in CpANP reached 10 min after exercise. CpANP was significantly related to PCWP and – although inconsistently and only in healthy horses – to echocardiographic indices of LA and LV size and function. CpcTnI was low throughout the study in both groups.ConclusionsCpANP is increased in horses with MR and is related to LA pressures and to left heart dimensions. MR is not necessarily associated with exercise intolerance and exercise-induced myocardial stress or damage.  相似文献   

5.
Serotonin (5-hydroxytryptamine [5-HT]) may induce metabolic effects in different cell types, including leukocytes. In horses, 5-HT is involved in physiological and behavioral functions. Physical exercise is known to increase the amounts of 5-HT both in brain and periphery, but so far, the signal mechanism in response to exercise is not known. The aim of the study was to investigate the effect of a racehorse intensive training session on plasma 5-HT levels, serotonin transporter (SERT), 5HT1A, 5-HT2A, 5-HT1B, 5-HT7 receptor, interleukin-1 beta, and tumor necrosis factor-alpha expression in horse peripheral blood mononuclear cells (PBMC). In particular, the research was carried out on 12 trained horses performing daily training. Plasma 5-HT levels were analyzed in platelet-poor plasma fraction by enzyme-linked immunosorbent assay at T0, T1, and T2 (pretraining, 30 minutes post-training, and 2 hours post-training session), respectively. Peripheral blood mononuclear cells were isolated to perform real-time polymerase chain reaction for the evaluation of SERT, 5-HT receptor, and cytokine mRNA levels. The results showed significantly increased levels of plasma 5-HT, 5HT1A, and 5-HT2A and significantly decreased levels of SERT, 5-HT1B, 5-HT7, and both cytokine mRNAs in PBMC at T1, compared with T0 and T2. The results were confirmed by in vitro experiment. Training may induce a lower degree of 5-HT storage and, therefore, a higher plasma 5-HT concentrations. Leukocyte 5-HT receptor mRNAs seem strongly influenced by the exercise. Observed changes suggest a transient neuroendocrinological response to the exercise. A better understanding of the influence of physical exercise on serotoninergic system could have potential application for the implementation of training protocols in racing horses.  相似文献   

6.
The effects of progesterone (P4) on follicular growth and fertility in ewes were examined. In Experiment 1, 22 ewes received either one or three packets of P4 (5 g/packed) or an empty packet subcutaneously (sc) from Days 5 to 15 of the estrous cycle (estrus = Day 0). On Day 6, P4-treated ewes received 12.5 mg of prostaglandin F2α. Follicles ⩾3 mm in diameter were observed via transrectal ultrasonography daily from Day 4 through estrus, corpora lutea (CL) were observed 5 to 7 d after estrus. Ewes with low (LOW; ⩽1 ng/ml; n = 5), intermediate (MED; > 1 and <2 ng/ml; n = 10), or normal (NOR; ⩾2 ng/ml; n = 7) P4 in jugular plasma on Days 7 through 15 differed in follicular development. The largest follicle at estrus was larger in ewes with LOW vs. MED and NOR P4 (7.8 ± 0.3 vs. 6.9 ± 0.2 mm; P < 0.05). Treatments differed in proportions of multiple-ovulating ewes, in which the oldest ovulatory follicle was first observed before Day 10 (LOW: 3 of 3, MED: 6 of 10, NOR: 0 of 5, respectively; P < 0.05). Estradiol was higher early in the treatment period in LOW ewes than in MED and NOR ewes (day × treatment; P < 0.05). In Experiment 2, ewes received 5 mg of P4 in corn oil (low progesterone [LP]; n = 51) or 2 ml of corn oil (CON; n = 49) sc every 12 hr on Days 6 through 14 of the estrous cycle before mating. LP ewes received 15 mg of prostaglandin F2α on Day 6. Mean serum P4 on Days 7 through 15 was 0.6 ± 0.1 ng/ml in LP and 1.9 ± 0.1 ng/ml in CON ewes. Eleven LP and 12 CON ewes were scanned daily from Day 4 through mating, and in all ewes (n = 93), CL were counted 10 d after mating and embryos were counted at 25, 40, and 60 d of gestation. In multiple-ovulating ewes, day of cycle of appearance was earlier for the oldest (Day 6.1 ± 0.8 vs. 10.4 ± 0.8) but not second oldest (Day 11.7 ± 1.0 vs. 12.2 ± 0.9) ovulatory follicles in LP compared with CON ewes. The conception rate was lower in LP (72%) than in CON ewes (98%; P < 0.01). However, numbers of CL 10 d after mating, and in pregnant ewes, numbers of embryos 25 d after mating and lambs born, did not differ with treatment. In summary, low P4 increased the size of the largest follicles and the age of the oldest ovulatory follicles. Embryos resulting from the ovulation of older and younger follicles in the same ewe did not differ in their ability to survive.  相似文献   

7.
Although pork producers typically aim to optimize growth rates, occasionally it is necessary to slow growth, such as when harvest facility capacity is limited. In finishing pigs, numerous dietary strategies can be used to slow growth so pigs are at optimal slaughter body weights when harvest facility capacity and/or access is restored. However, the impact of these diets on pork carcass quality is largely unknown. Thus, this study aimed to evaluate the efficacy of dietary strategies to slow growth in late finishing pigs and evaluate their effects on carcass composition and pork quality. Mixed-sex pigs (n = 897; 125 ± 2 kg BW) were randomly allotted across 48 pens and assigned to 1 of 6 dietary treatments (n = 8 pens/treatment): (1) Control diet representative of a typical finisher diet (CON); (2) diet containing 3% calcium chloride (CaCl2); (3) diet containing 97% corn and no soybean meal (Corn); (4) diet deficient in isoleucine (LowIle); (5) diet containing 15% neutral detergent fiber (NDF) from soybean hulls (15% NDF); and (6) diet containing 20% NDF from soybean hulls (20% NDF). Over 42 d, pen body weights and feed disappearance were collected. Pigs were harvested in 3 groups (14, 28, and 42 d on feed) and carcass data collected. From the harvest group, 1 loin was collected from 120 randomly selected carcasses (20 loins/treatment) to evaluate pork quality traits. Overall, ADG was reduced in CaCl2, Corn, and 20% NDF pigs compared with CON pigs (P < 0.001). However, ADFI was only reduced in CaCl2 and 20% NDF pigs compared with CON (P < 0.001). Feed efficiency was reduced in CaCl2 and Corn pigs compared with CON (P < 0.001). Hot carcass weights were reduced in CaCl2 pigs at all harvest dates (P < 0.001) and were reduced in Corn and 20% NDF pigs at days 28 and 42 compared with CON pigs (P < 0.001). In general, CaCl2 and 20% NDF diets resulted in leaner carcasses, whereas the Corn diet increased backfat by 42 d on test (P < 0.05). Loin pH was reduced and star probe increased in CaCl2 pigs compared with CON pigs (P < 0.05); no treatments differed from CON pigs regarding drip loss, cook loss, color, firmness, or marbling (P ≥ 0.117). Overall, these data indicate that several dietary strategies can slow finishing pig growth without evidence of behavioral vices. However, changes to carcass composition and quality were also observed, indicating quality should be taken into consideration when choosing diets to slow growth.  相似文献   

8.
ObjectiveTo evaluate latency and duration of a brachial plexus block technique in eastern box turtles performed with 2% lidocaine at three dose rates.Study designProspective, randomized, blinded crossover study.AnimalsAdult eastern box turtles, two for drug dose evaluation and a group of six (three male, three female) weighing 432 ± 40 g (mean ± standard deviation) for the main study.MethodsAnimals were randomly assigned to four brachial plexus blocks with lidocaine at 5, 10 and 20 mg kg–1 or 0.9% saline (treatments LID5, LID10, LID20 and CON, respectively), separated by 1 week. Treatment side was randomized and blocks were performed unilaterally. Baseline observations of mentation, heart rate (HR), respiratory rate (fR), skin temperature and limb response to manipulation or toe pinch were evaluated. Assessments were made every 10 minutes until 1 hour of normal sensory and motor function to the treated thoracic limb, or for a total of 2 hours if no block was evident.ResultsMotor and sensory blockade was achieved in treatments LID10 and LID20 in one turtle, with a latency of 10 minutes and duration of 50 minutes for both doses. Raising of the ipsilateral lower palpebra occurred with both blocks. Turtles administered lidocaine experienced higher HR compared with CON, and HR decreased over time for all individuals. Mentation and fR were not changed with any lidocaine dose.ConclusionsThe technique was unreliable in producing brachial plexus motor and sensory blockade at the lidocaine doses evaluated in this study. HR was higher in lidocaine-administered turtles but remained within normal limits for the species. No change in mentation or fR was observed among treatments.Clinical relevanceGeneral anesthesia with systemic analgesia is recommended for surgical procedures involving the chelonian thoracic limb. Further studies are needed to optimize a brachial plexus block in this species.  相似文献   

9.
The effects of peripheral (intravenous, i.v.) and central (intracerebroventricular, ICV) administrations of agonists of 5-HT1A, 5-HT2, 5-HT3 and 5-HT4 receptors were investigated in conscious sheep chronically fitted with intraparietal electrodes on the reticulum and the dorsal, ventral and caudo-ventral rumen. The 5-HT1A agonist 8-hydroxydipropylaminotetralin increased reticular and decreased ruminal spike burst frequency when given i.v. (80 μg/kg) and ICV (8 μg/kg). The 5-HT2 and 5-HT3 agonists, α-methylserotonin and 2-methylserotonin, induced a moderate inhibition of rumino-reticular contractions when given i.v. at 100 and 150 μg/kg, respectively, while marked inhibition was observed after ICV administration at doses of 10 and 5 μg/kg, respectively. The 5-HT4 agonist 5-methoxytryptamine strongly stimulated rumino-reticular motility by the ICV (10 μg/kg) route, whereas it induced a moderate inhibition when administered i.v. (200 μg/kg). The selective antagonist of 5-HT1A, 5-HT2, 5-HT3 and 5-HT4 receptors, spiroxatrine, ritanserin, granisetron and DAU 6285, respectively, blocked the responses of the respective agonists given by the same route. Moreover, the antagonists given ICV blocked the effects of the agonists given i.v. except for DAU 6285 ICV, which did not antagonize the inhibition induced by 5-methoxytryptamine i.v. It is concluded that the four types of serotonergic receptors investigated control rumino-reticular motility at the central level. However, according to the receptor type and the forestomach area (reticulum or rumen) this control may be stimulatory or inhibitory, demonstrating a pleiotropic role of serotonin in the control of rumino-reticular motility in sheep.  相似文献   

10.
ObjectiveTo elucidate the antinociceptive, physiologic and biochemical effects of electroacupuncture (EA) and xylazine in hybrid goats.Study designProspective experimental study.AnimalsA total of 30 female hybrid goats aged 1–2 years and weighing 25 ± 2.9 kg (mean ± standard deviation).MethodsThe goats were divided into five groups and administered xylazine (0.1 mg kg−1; group XYL.1), xylazine (0.3 mg kg−1; group XYL.3), EA (group EA), EA + xylazine (0.1 mg kg−1; group XYL.1-EA) and 0.9% saline (0.3 mL; control group CON). Nociceptive threshold and serum glucose concentration were measured at time 0 and at 15, 30, 45, 60 minutes and 24 hours after treatment. Nociceptive threshold was measured by passing potassium ions through the skin using potassium iontophoresis. Mean arterial pressure (MAP), heart rate (HR), respiratory frequency (fR) and rectal temperature (RT) were recorded at times 0 and at 5, 10, 15, 20, 30, 45, 60 minutes and 24 hours. Repeated-measures analyses were performed for each response variable; p < 0.05 was considered significant for all analyses.ResultsAntinociceptive effects in groups XYL.1 and XYL.3 were increased significantly at 15–60 minutes compared with group CON. Antinociceptive effect was higher in group XYL.1-EA than groups XYL.1 or EA at 15–60 minutes (p < 0.05). No significant difference in the nociceptive threshold was recorded in groups XYL.1-EA and XYL.3, except at 30 minutes. HR, MAP, fR, RT values were higher in group XYL.1-EA than in groups XYL.1 or XYL.3. Serum glucose concentration was higher in group XYL.3 at 15–60 minutes than in CON.Conclusions and clinical relevanceThe XYL.1 and EA combination was effective for antinociception with minimum physiologic alteration, suggesting that the combination may be a new and effective strategy for pain relief during clinical procedures in goats.  相似文献   

11.
Providing supplements that enhance the efficiency of feed utilization can reduce methane (CH4) emissions from ruminants. Protein supplementation is widely used to increase intake and digestion of low-quality forages, yet little is known about its impact on CH4 emissions. British-cross steers (n = 23; initial body weight [BW] = 344 ± 33.9 kg) were used in a three-period crossover design to evaluate the effect of protein supplementation to beef cattle consuming low-quality forage on ruminal CH4, metabolic carbon dioxide (CO2) emissions, forage intake, and ruminal fermentation. Steers individually had ad libitum access to low-quality bluestem hay (4.6% crude protein [CP]) and were provided supplemental protein based on (dry matter basis): cottonseed meal (CSM; 0.29% of BW daily; 391 g/d CP), dried distillers grains with solubles (DDGS; 0.41% of BW daily 563 g/d CP), or none (CON). Urea was added to DDGS to match rumen degradable protein provided by CSM. Ruminal CH4 and metabolic CO2 fluxes were obtained 2.4 ± 0.4 times per steer daily using an automated open-circuit gas quantification system (GreenFeed emission monitoring system; C-Lock Inc., Rapid City, SD). Forage intake increased (P < 0.01) with protein supplementation; however, no difference in forage intake (P = 0.14) was observed between CSM and DDGS treatments. Flux of CO2 (g/d) was greater (P < 0.01) for steers fed CSM and DDGS than for steers fed CON. Steers supplemented with CSM had greater (P < 0.01) CH4 emissions (211 g/d) than DDGS (197 g/d) both of which were greater (P < 0.01) than CON (175 g/d). Methane emissions as a proportion of gross energy intake (GEI) were lowest (P < 0.01) for DDGS (7.66%), intermediate for CSM (8.46%) steers, and greatest for CON (10.53%). Steers fed DDGS also had the lowest (P < 0.01) ruminal acetate:propionate ratio (3.60), whereas CSM (4.89) was intermediate, and CON (5.64) steers were greatest. This study suggests that the common practice of supplementing protein to cattle consuming low-quality forage decreases greenhouse gas emissions per unit of GEI.  相似文献   

12.
The experiment was conducted to investigate the effects of trace amounts of antibiotic on growth performance, diarrhea, systemic immunity, and intestinal health of weaned pigs experimentally infected with an enterotoxigenic Escherichia coli. Weaned pigs (n = 34, 6.88 ± 1.03 kg body weight [BW]) were individually housed in disease containment rooms and randomly allotted to one of the three dietary treatments: nursery basal diet (CON) and two additional diets supplemented with 0.5 or 50 mg/kg carbadox to the nursery basal diet (TRA or REC), respectively. The experiment lasted 18 d with 7 d before and 11 d after the first E. coli inoculation. The E. coli F18 inoculum was orally provided to all pigs with a dose of 1010 colony-forming unit (CFU)/3 mL for three consecutive days. Fecal and blood samples were collected on day 0 before inoculation and days 2, 5, 8, and 11 postinoculation (PI) to test the percentage of β-hemolytic coliforms in total coliforms and complete blood cell count, respectively. Sixteen pigs were euthanized on day 5 PI, whereas the remaining pigs were euthanized at the end of the experiment to collect the jejunal and ileal mucosa and mesenteric lymph node for gene expression and bacterial translocation, respectively. Pigs in REC had greater (P < 0.05) final BW and lower (P < 0.05) overall frequency of diarrhea compared with pigs in the CON and TRA groups. Pigs in TRA had the lowest (P < 0.05) average daily gain and feed efficiency from day 0 to 5 PI, highest (P < 0.05) percentage of β-hemolytic coliforms in fecal samples on days 2 and 5 PI, and greatest (P < 0.05) bacterial colonies in mesenteric lymph nodes on day 11 PI compared with pigs in the CON and REC groups. Pigs in TRA had the greatest (P < 0.05) neutrophils on day 5 PI and higher (P < 0.05) white blood cell counts and lymphocytes than other groups on day 11 PI. Pigs in TRA had the greatest (P < 0.05) serum C-reactive protein on days 2 and 5 PI and serum tumor necrosis factor-α on day 5 PI, compared with pigs in the CON and REC groups. Pigs fed REC had increased (P < 0.05) mRNA expression of zona occludens-1 (ZO-1) and occludin (OCDN) and reduced (P < 0.05) interleukin-1 beta (IL1B), interleukin-6 (IL6), and tumor necrosis factor-alpha (TNFA) in ileal mucosa on day 5 PI, compared with the CON, whereas TRA upregulated (P < 0.05) mRNA expression of IL1B, IL6, and cyclooxygenase-2 (COX2) in the ileal mucosa on day 11 PI, compared with the REC. In conclusion, trace amounts of antibiotic may exacerbate the detrimental effects of E. coli infection on pig performance by increasing diarrhea and systemic inflammation of weanling pigs.  相似文献   

13.
ObjectiveTo determine if pressure support ventilation (PSV) weaning from general anesthesia affects ventilation or oxygenation in horses.Study designProspective randomized clinical study.AnimalsTwenty client‐owned healthy horses aged 5 ± 2 years, weighing 456 ± 90 kg.MethodsIn the control group (CG; n = 10) weaning was performed by a gradual decrease in respiratory rate (fR) and in the PSV group (PSVG; n = 10) by a gradual decrease in fR with PSV. The effect of weaning was considered suboptimal if PaCO2 > 50 mmHg, arterial pH < 7.35 plus PaCO2 > 50 mmHg or PaO2 < 60 mmHg were observed at any time after disconnection from the ventilator until 30 minutes after the horse stood. Threshold values for each index were established and the predictive power of these values was tested.ResultsPressure support ventilation group (PSVG) had (mean ± SD) pH 7.36 ± 0.02 and PaCO2 41 ± 3 mmHg at weaning and the average lowest PaO2 69 ± 6 mmHg was observed 15 minutes post weaning. The CG had pH 7.32 ± 0.02 and PaCO2 57 ± 6 mmHg at weaning and the average lowest PaO2 48 ± 5 mmHg at 15 minutes post weaning. No accuracy in predicting weaning effect was observed for fR (p = 0.3474), minute volume (p = 0.1153), SaO2 (p = 0.1737) and PaO2/PAO2 (p = 0.1529). A high accuracy in predicting an optimal effect of weaning was observed for VT > 10 L (p = 0.0001), fR/VT ratio ≤ 0.60 breaths minute?1 L?1 (p = 0.0001), VT/bodyweight > 18.5 mL kg?1 (p = 0.0001) and PaO2/FiO2 > 298 (p = 0.0002) at weaning. A high accuracy in predicting a suboptimal effect of weaning was observed for VT < 10 L (p = 0.0001), fR/VT ratio ≥ 0.60 breaths minute?1 L?1 (p = 0.0001) and Pe′CO2 ≥ 38 mmHg (p = 0.0001) at weaning.Conclusions and clinical relevancePressure support ventilation (PSV) weaning had a better respiratory outcome. A higher VT, VT/body weight, PaO2/FiO2 ratio and a lower fR/VT ratio and Pe′CO2 were accurate in predicting the effect of weaning in healthy horses recovering from general anesthesia.  相似文献   

14.
The aim of the present study was to evaluate the inclusion of narasin, salinomycin, or flavomycin for 140 d on ruminal fermentation parameters, apparent nutrient digestibility, and performance of Nellore cattle offered a forage-based diet. In experiment 1, 32 rumen-cannulated Bos indicus Nellore steers [initial body weight (BW) = 220 ± 12.6 kg] were assigned to individual pens in a randomized complete block design according to their initial shrunk BW. Within block, animals were randomly assigned to 1 of 4 treatments: (1) forage-based diet without feed additives (CON; n = 8), (2) CON diet plus 13 ppm of narasin (NAR; n = 8), (3) CON diet plus 20 ppm of salinomycin (SAL; n = 8), or (4) CON diet plus 3 ppm of flavomycin (FLA; n = 8). The experimental period lasted 140 d and was divided into 5 periods of 28 d each. The inclusion of feed additives did not impact (P ≥ 0.17) dry matter intake (DMI), nutrient intake, and apparent total tract digestibility of nutrients. Nonetheless, steers fed NAR had lower (P < 0.01) molar proportion of acetate compared with CON, SAL, and FLA steers, whereas ruminal acetate tended to be greater (P < 0.09) for SAL vs. CON and FLA, but did not differ (P = 0.68) between CON vs. FLA steers. Ruminal propionate was the highest (P < 0.01) for steers fed NAR and did not differ (P > 0.20) between CON, SAL, and FLA. Consequently, NAR steers had the lowest (P < 0.01) Ac:Pr ratio, whereas Ac:Pr did not differ (P > 0.18) among CON, SAL, and FLA. Total volatile fatty acids were greater (P < 0.04) for NAR and CON vs. SAL and FLA, but did not differ (P > 0.67) among NAR vs. CON and SAL vs. FLA. In experiment 2, 164 Nellore bulls (initial shrunk BW = 299 ± 2.5 kg) were assigned to feedlot pens for 140 d in a randomized complete block design. Within block (n = 10), animals were randomly assigned to the same treatments used in experiment 1. Average daily gain was greater (P < 0.01) in NAR vs. CON, SAL, and FLA bulls, and did not differ (P > 0.12) between CON, SAL, and FLA bulls. Bulls fed NAR had greater (P < 0.02) DMI (as kg/d or % BW) and final shrunk BW compared with CON, SAL, and FLA bulls, whereas DMI and final shrunk BW did not differ (P > 0.26) between CON, SAL, and FLA bulls. Feed efficiency, however, was not impacted (P = 0.51) by any feed additives used herein. Collectively, narasin was the only feed additive that benefited performance and ruminal fermentation of Nellore animals fed a forage-based diet.  相似文献   

15.
To assess the efficacy of bis-glycinate bound Zn, 36 crossbred wethers (34 ± 2 kg) were sorted by body weight into three groups and stagger started on a Zn-deficient diet (18 mg Zn/kg dry matter [DM]; 22.5% neutral detergent fiber [NDF]) for 45 d prior to a 15-d metabolism period (10 d adaptation and 5 d collection). On day 46, lambs were randomly assigned to dietary treatments (four lambs treatment−1group−1): no supplemental Zn (CON) or 15 mg supplemental Zn/kg DM (ZINC) as Zn sulfate (ZS) or bis-glycinate (GLY; Plexomin Zn, Phytobiotics). Blood was collected from all lambs on days 1, 44, 56, and 61. Liver, jejunum, and longissimus dorsi samples were collected after euthanasia on day 61. Gene expression was determined via quantitative real-time polymerase chain reaction. Data were analyzed using ProcMixed of SAS (experimental unit = lamb; fixed effects = treatment, group, and breed) and contrast statements assessed the effects of supplemental Zn concentration (ZINC vs. CON) and source (GLY vs. ZS). After 15 d of Zn supplementation, plasma Zn concentrations were greater for ZINC vs. CON and GLY vs. ZS (P ≤ 0.01); tissue Zn concentrations were unaffected (P ≥ 0.27). Liver Cu concentrations were lesser for ZINC vs. CON (P = 0.03). Longissimus dorsi Mn concentrations were greater for ZINC vs. CON (P = 0.05) and tended to be lesser for GLY vs. ZS (P = 0.09). Digestibility of DM, organic matter (OM), and NDF was lesser for ZINC vs. CON (P ≤ 0.05); acid detergent fiber digestibility tended to be greater for GLY vs. ZS (P = 0.06). Nitrogen retention (g/d) tended to be greater for GLY vs. ZS (P = 0.10), and N apparent absorption was lesser for ZINC vs. CON (P = 0.02). Zinc intake, fecal output, retention, and apparent absorption were greater for ZINC vs. CON (P ≤ 0.01). Apparent absorption of Zn was −5.1%, 12.8%, and 15.0% for CON, ZS, and GLY, respectively. Nitrogen and Zn retention and apparent absorption were not correlated for CON (P ≥ 0.14) but were positively correlated for ZINC (retention: P = 0.02, r = 0.52; apparent absorption: P < 0.01, r = 0.73). Intestinal expression of Zn transporter ZIP4 was lesser for ZINC vs. CON (P = 0.02). Liver expression of metallothionein-1 (MT1) tended to be greater for GLY vs. ZS (P = 0.07). Although Zn apparent absorption did not differ between sources (P = 0.71), differences in post-absorptive metabolism may be responsible for greater plasma Zn concentrations and liver MT1 expression for GLY-supplemented lambs, suggesting improved bioavailability of GLY relative to ZS.  相似文献   

16.
The present study was designed to examine the effects of intracerebroventricular (ICV) injection of Dopamine (10, 20 and 40 nmol), L-DOPA (dopamine precursor; 62.5, 125 and 250 nmol), 6-OHDA (dopamine inhibitor; 75, 150 and 300 nmol), SCH 23390 (D1 antagonist; 2.5, 5 and 10 nmol), AMI-193 (D2 antagonist; 2.5, 5 and 10 nmol), NGB2904 (D3 antagonist; 3.2, 6.4 and 12.8 nmol), L-741 T742 (D4 antagonist; 1.5, 3 and 6 nmol) on food intake in FD3 chickens. At following, birds were ICV injected using 8-OH-DPAT (5-HT1A agonist; 15.25 nmol) and SB242084 (5-HT2C antagonist; 1.5 μg) prior dopamine (40 nmol) injection. Cumulative food intake was determined until 3 h post-injection. According to the results, dopamine significantly decreased food intake in chickens (p?<?0.05). The inhibitory effect of dopamine on food intake was decreased by SCH 23390 pretreatment (P?<?0.05), but AMI-193, NGB2904 and L-741, 742 had no effect on food intake induced by dopamine. In addition, hypophagic effect of dopamine was attenuated by SB242084 (P?<?0.05), but 8-OH-DPAT had no effect. These results suggest that dopamine decrease food intake via D1 receptor and there is an interaction between dopaminergic and serotonergic systems via 5-HT2C receptor in chickens.  相似文献   

17.
This experiment evaluated the impacts of administering a bovine appeasing substance (BAS) to beef calves at weaning on their performance, physiological responses, and behavior during a 42-d preconditioning program. Eighty calves (40 heifers and 40 steers; 90% British × 10% Nellore) were weaned at 233 ± 2 d of age (day 0); ranked by sex, weaning age, and body weight (BW); and assigned to receive BAS (IRSEA Group, Quartier Salignan, France; n = 40) or placebo (diethylene glycol monoethyl ether; CON; n = 40). Treatments (5 mL) were topically applied to the nuchal skin area of each animal following dam separation. Within treatment, calves were allocated to one of eight drylot pens (four pens per treatment; pen being the experimental unit) and received a free-choice total mixed ration (TMR) from day 0 to 42, intake of which was assessed daily. Live behavior observations were conducted on days 1, 2, 4, 8, 16, and 32. Temperament was assessed and blood samples were collected via jugular venipuncture on days −21, 0, 3, 7, 14, 28, and 42. Hair samples were collected from the tail switch on days 0, 14, 28, and 42. Calves were vaccinated against bovine respiratory disease viruses on days −21 and 0. Average daily gain from day 0 to 42 did not differ between treatments (P = 0.57) but was greater (P = 0.05) in BAS vs. CON calves from day 0 to 28. Intake of TMR was greater (P = 0.05) during the first week for BAS vs. CON calves (treatment × week; P = 0.08). The mean proportion of calves feeding simultaneously and performance of social and play behaviors were greater (P ≤ 0.05) for BAS vs. CON calves. Escape attempts were greater (P < 0.01) for BAS vs. CON calves on day 1 (treatment × day; P = 0.03). Exit velocity was greater (P = 0.04) for CON vs. BAS calves on day 14 and tended (P = 0.10) to be greater for CON vs. BAS calves on day 7 (treatment × day; P = 0.03). Mean plasma concentrations of haptoglobin were greater (P = 0.02) in CON vs. BAS calves. Hair cortisol concentrations were greater (P = 0.05) in CON vs. BAS calves on day 14 (treatment × day; P = 0.03). Mean serum concentrations of antibodies against bovine viral diarrhea virus were greater (P = 0.02) in BAS vs. CON calves. Collectively, BAS administration to beef calves at weaning alleviated stress-induced physiological reactions, improved temperament evaluated via chute exit velocity, enhanced humoral immunity acquired from vaccination, and appeared to have accelerated adaptation to novel management scheme and environment.  相似文献   

18.
The importance of polyunsaturated fatty acids (PUFAs) within the different biological functions of animals has been widely recognized. In this study, exercise and PUFAs supplementation effects on serum triglycerides, total cholesterol, and nonesterified fatty acids (NEFAs) concentration were evaluated in athletic horses. Two sport horse types (10 Italian saddle jumpers and 10 Thoroughbreds) were equally divided into two groups. Jumpers and Thoroughbred experimental groups (AJ and AT) received 4-week PUFAs supplementation and control groups (BJ and BT) received no dietary supplement. Before starting the PUFAs supplementation (T0) and at the end of the experimental period (T4), horses were subjected to simulated events. From each subject, blood samples were collected every 7 days at rest, before and after the first test (T0R and T0PE), and before and after the second test (T4R and T4PE). Higher triglycerides and NEFA concentrations at T0PE and T4PE than T0R and T4R in both groups were found as a result of exercise (P < .005), but lower triglycerides and NEFA concentrations at T4PE in group AJ than group BJ (P < .05) and in group AT (P < .005) than group BT were found as a result of PUFAs supplementation. Effects of PUFAs supplementation was highlighted by the statistically significant lower triglycerides and NEFA concentrations found at T4PE than T0PE in groups AJ (P < .05) and AT (triglycerides: P < .05; NEFAs: P < .0001).  相似文献   

19.
Functional corpora lutea (CL) are required for pregnancy establishment and gestational maintenance in swine, and CL function is susceptible to environmental influences. Manganese (Mn) could be critical in regulating CL function since it is a component of the antioxidant enzyme Mn superoxide dismutase (MnSOD) as well as enzymes involved in cholesterol and steroid hormone synthesis. We hypothesized that a more bioavailable dietary Mn source would increase Mn content in the CL thereby influencing luteal function during the mid-luteal phase of the estrous cycle. Postpubertal gilts (n = 32) were assigned to one of four gestation diets. The control diet (CON) met or exceeded National Research Council (2012) requirements and was formulated to contain 20 parts per million (ppm) of added Mn in the form of Mn sulfate. Three additional diets included 20 (treatment [TRT]1), 40 (TRT2), or 60 (TRT3) ppm of added Mn from a Mn–amino acid complex (Availa-Mn; Zinpro Corporation) instead of Mn sulfate. Dietary treatment began at estrus synchronization onset and continued through 12 days post estrus (dpe) of the ensuing estrous cycle. Blood samples were collected at estrus onset, which was assigned as 0 dpe, as well as 4, 8, and 12 dpe. Gilts were euthanized and tissues were collected at 12 dpe. Serum progesterone (P4) increased (P < 0.01) from 0 to 12 dpe but was unaffected by dietary treatment (P = 0.15) and there was no effect of the interaction between day and treatment (P = 0.85). Luteal Mn content increased (P ≤ 0.05) by 19%, 21%, and 24% in gilts fed TRT1, TRT2, and TRT3, respectively, compared to CON. Luteal P4 concentrations decreased (P = 0.03) 25%, 26%, and 32% in gilts fed TRT1, TRT2, and TRT3, respectively, compared to CON. Relative to CON gilts, CL calcium content decreased (P = 0.02) by 36%, 24%, and 34% for TRT1, TRT2, and TRT3 gilts, respectively. Collectively, these data support the hypothesis that feeding a more bioavailable Mn source increases Mn accumulation in CL tissue. If and how this influences CL function may be related to altered luteal P4 concentrations.  相似文献   

20.
Study objectives were to determine the effects of continuously infusing glucose (GLC) or casein (CAS) into the terminal ileum on biomarkers of metabolism, inflammation, and intestinal morphology in growing pigs. Crossbred gilts (n = 19; 81 ± 3 kg body weight [BW]) previously fitted with T-cannulas at terminal ileum were used in the current experiment. Following 4 d of acclimation, pigs were enrolled in 2 experimental 4-d periods (P). During P1, pigs were housed in individual pens and fed ad libitum for collection of baseline parameters. At the beginning of P2, pigs were assigned to 1 of 3 infusion treatments: 1) control (CON; water; 3 liters/d; n = 7), 2) GLC (dextrose 50%; 500 g/d; n = 6;), or 3) CAS (casein sodium salt; 300 g/d; n = 6). Water, GLC, and CAS solutions were continuously infused at a rate of 125 mL/h for the entirety of P2. Animals were euthanized at the end of P2, and intestinal tissue was collected. During P2, average daily feed intake differed across treatments and was reduced in GLC compared with CON pigs (14%), while CAS pigs consumed an intermediate amount (P = 0.05). Average daily gain and final BW were similar across treatments. A treatment by time interaction was observed for blood urea nitrogen (BUN; P < 0.01), as it decreased in GLC (21%) while it gradually increased in CAS (76%) pigs relative to CON pigs. Mild hyperthermia occurred with both GLC and CAS infusions relative to CON (+0.3 and 0.2 °C, respectively; P < 0.01). Blood neutrophils increased in CAS relative to CON pigs (26%) but remained similar between CON and GLC treatments (P < 0.01). Blood monocytes decreased in GLC relative to CON pigs (24%) while CAS pigs had an intermediate value (P = 0.03). Circulating lipopolysaccharide binding protein tended to decrease in GLC (29%) relative to CON pigs but remained similar between CON and CAS pigs (P = 0.10). Plasma tumor necrosis factor-alpha was similar across treatments. Ileum villus height:crypt depth was increased in CAS compared with CON pigs (33%; P = 0.05) while GLC pigs had an intermediate value. Colon myeloperoxidase-stained area increased in CAS compared with CON pigs (45%; P = 0.03) but remained similar between GLC and CON pigs. In summary, continuously infusing GLC or CAS into the terminal ileum appeared to stimulate a mild immune response and differently altered BUN patterns but had little or no effects on blood inflammatory markers, intestinal morphology, or key production parameters.  相似文献   

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