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1.
The objective of this study was to evaluate oxidative metabolism of glucose, glutamate, and glutamine by isolated ovine enterocytes in the presence of other metabolic fuels in vitro. A mixed mucosal primary cell culture containing enterocytes was isolated from crossbred wether sheep (n = 6) fed a mixed forage-concentrate diet and incubated for 90 min with 1 mM U-14C-glucose, -glutamate, or -glutamine and additional substrates (water as negative control, acetate, propionate, butyrate, glucose, glutamate, or glutamine) at concentrations of 0.1, 1.0, and 10.0 mM. Oxidation of labeled substrates to CO2 and net production of lactate and pyruvate in incubation media were measured. Oxidation of glucose and glutamine to CO2 was decreased (P < 0.05) by 5 to 40% in the presence of additional substrates except acetate. Our observation that glutamine oxidation can be decreased by the presence of additional substrates is contrary to observations in the literature using enterocytes from nonruminants, indicating that ruminant enterocytes might rely on glutamine to a lesser extent as an energy source. Net glucose utilization was decreased (P < 0.05) 16% by propionate (10 mM) compared with control but was not affected by the other additional substrates. Glutamate oxidation to CO2 was decreased 28% (P < 0.05) in the presence of propionate (10 mM) or by 17 and 33% in the presence of glutamine (1.0 and 10 mM, respectively), but not by that of the other additional substrates. Acetate did not affect the oxidation of glucose, glutamate, and glutamine. Propionate decreased (P < 0.05) the oxidation of glucose and glutamate only at the highest concentration (10 mM), indicating that the sparing effects of propionate on substrate oxidation are affected by its concentration in the incubation media. These observations indicate that ruminant enterocytes possess metabolic flexibility for oxidative metabolism of glucose, glutamine, and glutamate depending on the type and concentration of available additional substrates.  相似文献   

2.
Crossbred wether lambs were used to assess the effect of altered forage:concentrate ratio and metabolizable energy intake on metabolism of substrates by ruminal epithelium using an isolated cell system. Lambs (n = 28; 20.1 +/- 3 kg BW) were assigned randomly to a factorial arrangement of dietary treatments consisting of either 75% forage or 75% concentrate fed once daily at either .099 or .181 Mcal ME x(kg BW(.75))(-1) x d(-1) for 52 d. After a 52-d feeding period, isolated rumen epithelial cells (IREC) were incubated in the presence of an oxidizable substrate with a single 14C label (acetate, propionate, butyrate, glucose, glutamate, and glutamine) at concentrations ranging from .1 to 50 mM, and substrate oxidation to 14CO2 or metabolism to beta-hydroxybutyrate (beta-HBA), acetoacetate, pyruvate, and lactate was determined. For all substrates, oxidation to CO2 was concentration-dependent and saturable within the physiological range. Differences in substrate oxidation to CO2 by IREC at specific substrate concentrations did not affect Vmax (maximal rate of substrate oxidation, nmol oxidized to CO2 x 1 x 10(6) cells(-1) x 90 min(-1)) and K(ox) (concentration of substrate at which half Vmax oxidation rate is achieved, mmoles/L) estimates for the dietary treatments. Production of beta-HBA from butyrate by IREC from the lambs fed 75% forage was not affected by ME intake; however, production was elevated by high ME intake of the 75% concentrate diet (diet x intake interaction; P < .02). Acetoacetate production from butyrate by IREC from lambs fed at high ME intake was greater (P = .001) than from those fed at low ME intake. Lactate and pyruvate production from glucose, glutamate, and propionate were generally unaffected by dietary treatment; however, rate of glutamine metabolism to lactate and pyruvate by IREC was increased with increased ME intake. The observed changes in metabolite production rates across groups did not affect the predicted Vmax and K(ox) parameter estimates. The estimated K(ox) values corroborate that VFA are the primary oxidizable fuels used by ruminal epithelial cells while illustrating that other substrates such as glucose, glutamate, and glutamine would not be expected to be oxidized extensively in vivo due to the high K(ox) relative to substrate concentrations in vivo. In conclusion, the capacity of isolated ruminal epithelial cells to oxidize substrates was largely unaffected by ME intake or dietary forage:concentrate ratio of the diet.  相似文献   

3.
Twenty calves (7 mo old) were blocked by breed, sex, and weight into five groups of four calves and randomly assigned to either a 90% forage (alfalfa) or a 90% grain (50% sorghum and 50% wheat) diet fed at one (1M) or two (2M) times NEm for 140 d. Samples of ruminal epithelial tissue were collected from the anterior ventral sac, and papillae were cut free by hand and used for in vitro incubations and acyl-CoA synthetase assays. Substrates were acetate (90 mM), propionate (60 mM), butyrate (30 mM), and glucose (20 mM). Net productions of beta-hydroxybutyrate and acetoacetate from acetate were greater (P less than .01) with the 2M feeding; however, 14CO2 production from acetate was greater (P less than .05) with the grain diet. Net production of lactate (P = .09) and pyruvate (P less than .01) from propionate increased with the 2M feeding, whereas net lactate production from glucose decreased (P less than .01). Uptakes of VFA were similar with 1M and 2M feeding and were about 10-fold greater than uptakes of glucose. Production of 14CO2 from propionate was two- to fivefold greater than from acetate, butyrate, or glucose. Oxygen consumption was greater (P less than .01) with 2M feeding and unaffected by substrate. Activities of butyryl-CoA synthetase (nmol.mg of tissue-1.h-1) were greater (P less than .05) for animals consuming the forage diets. Addition of butyrate inhibited acetyl- and propionyl-CoA synthetase activity by 63 and 92%, respectively for all dietary treatments. Overall, metabolism of ruminal epithelial tissue tended to increase with the 2M feeding. Influence of dietary forage content on metabolism and activity of acyl-CoA synthetases was minimal, but the high-forage diet caused slight increases.  相似文献   

4.
Splanchnic metabolism of energy-yielding nutrients and their uptake by the hind limb were studied in finishing lambs receiving ryegrass harvested at grazing stage (ear at 10 cm) with or without barley supplementation. Six ruminally cannulated and multicatherized lambs (40.2 +/- 1.5 kg) were fed with frozen ryegrass (RG) at 690 kJ of metabolizable energy intake (MEI) x d(-1) x BW(-0.75) successively with and without barley supplementation (RG + B), according to a triplicated Latin square design. Barley supplementation represented 21% of DM intake and increased the MEI by 32% (P < 0.002). In ruminal fluid, barley supplementation increased the acetate and butyrate concentrations by 21.2 and 49.6%, respectively (P < 0.04), without modifying those of propionate. Thus, molar proportions of acetate and butyrate were not modified, and those of propionate tended (P < 0.06) to decrease from 26 to 23%. As a result, the net portal appearance of propionate was not modified. Net portal appearance of butyrate and beta-hydroxybutyrate increased (P < 0.03), and that of acetate was not modified. Consequently, hepatic uptake of butyrate increased and probably spared acetate from hepatic metabolism. The hepatic fractional extraction of propionate decreased (P < 0.03), whereas the net flux of lactate switched from a net release to a net uptake, suggesting an alteration in the contribution of gluconeogenic substrates to glucose synthesis without modification in net hepatic glucose release. As a consequence, barley supplementation increased net splanchnic release of acetate (P < 0.02), propionate (P < 0.001), and beta-hydroxybutyrate (P < 0.01) by 60, 157, and 78%, respectively. In addition, the net splanchnic release of insulin increased (P < 0.03) because of a decrease (P < 0.02) in its hepatic extraction. Despite those changes, the net uptake of nutrients by the hind limb was not modified and even decreased in the case of glucose (P < 0.02), suggesting a stimulation of lipogenesis in adipose tissues. Results from the present study suggested that supplementation of a ryegrass-based diet would likely have little effect on the orientation of muscle energy metabolism and on meat quality because the net uptake of nutrients by the hind limb was unchanged.  相似文献   

5.
Recent molecular studies have revealed complex bacterial, fungal, archaeal, and viral communities in the gastrointestinal tract of dogs and cats. More than 10 bacterial phyla have been identified, with Firmicutes, Bacteroidetes, Proteobacteria, Fusobacteria, and Actinobacteria constituting more than 99% of all gut microbiota. Microbes act as a defending barrier against invading pathogens, aid in digestion, provide nutritional support for enterocytes, and play a crucial role in the development of the immune system. Of significance for gastrointestinal health is their ability to ferment dietary substrates into short-chain fatty acids, predominantly to acetate, propionate, and butyrate. However, microbes can have also a detrimental effect on host health. Specific pathogens (e.g., Salmonella, Campylobacter jejuni, and enterotoxigenic Clostridium perfringens) have been implicated in acute and chronic gastrointestinal disease. Compositional changes in the small intestinal microbiota, potentially leading to changes in intestinal permeability and digestive function, have been suggested in canine small intestinal dysbiosis or antibiotic-responsive diarrhea. There is mounting evidence that microbes play an important role in the pathogenesis of canine and feline inflammatory bowel disease (IBD). Current theories for the development of IBD favor a combination of environmental factors, the intestinal microbiota, and a genetic susceptibility of the host. Recent studies have revealed a genetic susceptibility for defective bacterial clearance in Boxer dogs with granulomatous colitis. Differential expression of pathogen recognition receptors (i.e., Toll-like receptors) were identified in dogs with chronic enteropathies. Similarly to humans, a microbial dysbiosis has been identified in feline and canine IBD. Commonly observed microbial changes are increased Proteobacteria (i.e., Escherichia coli) with concurrent decreases in Firmicutes, especially a reduced diversity in Clostridium clusters XIVa and IV (i.e., Lachnospiraceae, Ruminococcaceae, Faecalibacterium spp.). This would indicate that these bacterial groups, important short-chain fatty acid producers, may play an important role in promoting intestinal health.  相似文献   

6.
本研究旨在探讨饲粮中添加香菇多糖对断奶大鼠生长性能、抗氧化能力和肠道健康的影响。试验选取20只健康的断奶Wistar大鼠,按照体重相近的原则分为2个组(每组10只),分别饲喂基础饲粮和添加了84 mg/kg香菇多糖(香菇多糖有效含量为30%)的试验饲粮。试验期为21 d。结果表明:饲粮中添加84 mg/kg香菇多糖显著提高了断奶大鼠的平均日增重和平均日采食量(P0.05),显著降低了料重比(P0.05);饲粮中添加84 mg/kg香菇多糖显著提高了断奶大鼠血清和空肠的总抗氧化能力(P0.05),不同程度降低了血清(P0.05)和空肠(P=0.08)丙二醛含量;饲粮中添加84 mg/kg香菇多糖显著提高了断奶大鼠空肠黏膜绒毛高度和绒毛高度/隐窝深度(P0.05);此外,饲粮添加84 mg/kg香菇多糖提高了断奶大鼠盲肠食糜中乳酸菌的数量(P=0.07),显著降低了盲肠食糜中大肠杆菌的数量(P0.05),并显著提高了盲肠食糜中乙酸、丙酸、丁酸和总挥发性脂肪酸的含量(P0.05)。综上所述,在断奶大鼠饲粮中添加84 mg/kg香菇多糖(香菇多糖有效含量为30%)可以改善其抗氧化能力、空肠黏膜形态结构和盲肠菌群结构,进而提高生长性能。  相似文献   

7.
Freeze-dried ileal effluent (1% wt/vol) from cannulated pigs fed rice-based diets with the inclusion of either animal protein (CON), animal protein plus potato starch (PS), animal protein plus sugar beet pulp (SBP), or animal protein plus wheat bran (WB) was incubated anaerobically at pH 6.0 in fermenters containing 5% (wt/vol) fecal slurry comprising mineral salts medium and 50 g/L of fresh feces from pigs fed the same diets as the cannulated pigs. Samples were collected from the fermenters at 0, 2, 4, 12, 24, and 48 h during in vitro fermentation for measuring nonstarch polysaccharides (NSP), starch, and short-chain fatty acids (SCFA). Results showed that the major SCFA produced were acetate, propionate, and butyrate. The inclusion of soluble dietary fiber (diet SBP) caused the highest concentrations of acetate, propionate, butyrate, and total SCFA, whereas the increase in the production of propionate resulting from the addition of insoluble dietary fiber (diet WB) only occurred at the initial stages during 48 h in vitro fermentation. At all sampling occasions (except for 4 h), the levels of butyrate were increased (P < 0.01) by resistant starch compared with fiber sources, showing that a higher level of butyrate can be achieved through microbial fermentation by potato starch. Lowered (P < 0.05) butyrate concentrations were observed with diet WB during in vitro fermentation. With the inclusion of fiber sources, the energy originating from SCFA was similar to that from NSP disappearance, whereas the values were lower (P < 0.05) from NSP disappearance than for SCFA generated without fiber sources supplemented. We conclude that more substrate is available in ileal effluent with the addition of soluble dietary fiber, and an increased level of butyrate could be achieved through microbial fermentation by resistant starch.  相似文献   

8.
OBJECTIVE: To determine effects of short-chain fatty acids (SCFA) on canine colonic smooth muscle. SAMPLE POPULATION: Colonic tissue obtained from 14 healthy dogs. PROCEDURE: Short-chain fatty acid (SCFA; acetate, propionate, and butyrate; 1 to 100 mmol/L)-induced contractions were compared with responses obtained with acetylmethylcholine (AMCh; 10(-4) mol/L). Roles of enteric neurons, cholinergic receptors, calcium stores in the sarcoplasmic reticulum, and extracellular calcium in the SCFA-induced responses were investigated by incubating muscle strips with tetrodotoxin (1 micromol/L), atropine (1 micromol/L), ryanodine (10 micromol/L), nifedipine (1 micromol/L), ethylene glycol-bis (beta-aminoethylether)-N,N,N',N'-tetra-acetate (EGTA; 0.1 mmol/L), or an extracellular calcium-depleted (zero extracellular calcium) solution prior to the addition of propionate or butyrate. RESULTS: Incubation with SCFA elicited isometric stress responses (0.25 to 2.15 x 10(4) N/m2) in colonic longitudinal smooth muscle. Maximal responses to butyrate and propionate (50 mmol/L) were 37 and 23%, respectively, of the maximal AMCh response. Acetate was least effective in stimulating contractile responses. Tetrodotoxin and atropine did not affect SCFA-induced contractions. Nifedipine and zero extracellular calcium solution abolished responses to butyrate and propionate, whereas EGTA attenuated (> 60%) but did not abolish those responses. Ryanodine did not affect SCFA-induced contractile responses. The SCFA did not affect colonic circular smooth muscle. CONCLUSIONS AND CLINICAL RESPONSE: The SCFA stimulate longitudinal but not circular colonic smooth muscle contractions via a direct effect on smooth muscle. The mechanism of the SCFA effect appears to involve the influx of extracellular calcium. These findings may account for some of the effects of fiber on canine colonic motility [corrected].  相似文献   

9.
To investigate the metabolism of 1,2-propanediol (PPD) in lactating cows independently of normal rumen microbial metabolism, three ruminally cannulated lactating Holstein cows were subjected to three experimental infusion protocols under washed reticulo-ruminal conditions in a Latin square design. Reticulo-ruminal absorption rates were maintained for 420 min by continuous intraruminal infusion of VFA and PPD. With the control treatment, 1,246 +/- 39 mmol/ h of acetate and 213 +/- 5 mmol/h of butyrate were absorbed from the reticulorumen. With the propionate treatment, 1,148 +/- 39 mmo/h of acetate, 730 +/- 23 mmol/h of propionate and 196 +/- 5 mmol/h of butyrate were absorbed from the reticulorumen. With PPD treatment, 1,264 +/- 39 mmol/h of acetate, 220 +/- 5 mmol/h of butyrate and 721 +/- 17 mmol/h of PPD were absorbed from the reticulorumen. Glucose irreversible loss rate (ILR), as well as the relative enrichment of plasma lactate and alanine, were determined by primed continuous infusion of [U-13C]glucose in a jugular vein. Treatments did not affect (P > 0.10) the plasma concentrations of glucose (4.2 +/- 0.1 mmoVL), alanine (0.14 +/- 0.01 mmol/L), or insulin (80 +/- 25 pmol/L). The plasma concentration of lactate was higher (P < 0.05) with both propionate (0.84 +/- 5 mmol/L) and PPD treatment (0.81 +/- 5 mmol/ L) compared with the control treatment (0.29 +/- 0.5 mmol/L). The plasma concentration of pyruvate was higher (P < 0.05) with the propionate treatment (0.09 +/- 0.01 mmol/L) compared with the control treatment (0.03 +/- 0.01 mmol/L). The plasma concentration of 3-hydroxybutyrate was lower (P < 0.05) with the propionate treatment (0.15 +/- 0.03 mmol/L) compared with the control treatment (0.40 +/- 0.03). With the PPD treatment, the plasma concentrations of pyruvate and 3-hydroxybutyrate were in between the other treatments and tended (P < 0.10) to be different from both. The plasma concentration of PPD increased throughout the infusion period with the PPD treatment and reached a concentration of 4.9 +/- 0.6 mmol/L at 420 min. The ILR of glucose was not affected (P > 0.10) by treatments (441 +/- 35 mmol/h). The relative 13C enrichment of plasma lactate compared with that of glucose decreased (P < 0.05) with the PPD treatment compared with the control treatment (44 to 21 +/- 3%). It was concluded that PPD has a low rate of metabolism in cows without a normal functioning rumen, although about 10% of the absorbed PPD was metabolized into lactate.  相似文献   

10.
Two experiments were conducted to determine the effects of dietary sodium butyrate on growth performance and response to Escherichia coli lipopolysaccharide (LPS) in weanling pigs. In a 28-d experiment, 180 pigs (initial BW 6.3 kg) were fed 0, 0.05, 0.1, 0.2, or 0.4% sodium butyrate, or 110 mg/kg of dietary tylosin. There was no effect of dietary sodium butyrate or tylosin on overall G:F, but there was a linear trend (P < 0.07) toward decreased ADFI and ADG as levels of sodium butyrate increased. In a second 28-d experiment, 108 pigs (initial BW 6.3 kg) were assigned to 1 of 3 dietary treatments: 1) no antibiotics, 2) 0.2% sodium butyrate, or 3) 55 mg/kg of carbadox. On d 14, a subset of pigs from the no-antibiotic and butyrate treatment groups was challenged with E. coli LPS or injected with sterile saline in a 2 x 2 factorial arrangement (+/-LPS challenge; +/-dietary butyrate; n = 6 pigs/treatment group). Four hours after LPS challenge, blood samples were obtained, and samples of LM, liver, and ileum were collected for gene expression analysis. Serum samples were analyzed for IL-6, tumor necrosis factor alpha (TNFalpha), alpha(1)-acid glycoprotein, cortisol, IGF-I, insulin, and metabolites. The relative abundance of tissue cytokine and IGF-I mRNA was measured by real-time PCR. Feeding diets containing sodium butyrate or carbadox did not alter ADG or ADFI compared with pigs fed the control diet. From d 0 to 14, pigs fed diets containing 0.2% sodium butyrate had decreased (P < 0.05) ADG and tended (P < 0.06) to have decreased G:F compared with animals fed diets containing carbadox. Challenge with LPS increased (P < 0.05) serum cytokines and cortisol and decreased (P < 0.05) serum glucose and triglycerides. Injection with LPS increased (P < 0.05) the relative abundance of hepatic IL-6 and TNFalpha mRNA, increased (P < 0.05) LM TNFalpha mRNA content, and decreased (P < 0.05) IGF-I mRNA in LM. For serum cortisol, there was an interaction (P < 0.05) between dietary butyrate and LPS. The increase in serum cortisol attributable to LPS was greater (P < 0.05) in pigs fed butyrate than in pigs fed the control diet. There tended (P < 0.10) to be an interaction between LPS and diet and for butyrate to increase the relative abundance of IL-6 mRNA in LM. Carbadox did not alter cytokine or IGF-I mRNA or serum metabolites, but did decrease (P < 0.05) serum TNFalpha. These data indicate that dietary sodium butyrate does not enhance growth performance, but may regulate the response to inflammatory stimuli in weanling pigs.  相似文献   

11.
Four steers fitted with a ruminal cannula and chronic indwelling catheters in the mesenteric artery, mesenteric vein, hepatic portal vein, hepatic vein, and the right ruminal vein were used to study VFA absorption from bicarbonate buffers incubated in the washed reticulorumen, and metabolism by splanchnic tissues. Portal and hepatic vein blood flows were determined by infusion of p-aminohippurate into the mesenteric vein. The steers were subjected to four experimental treatments in a Latin square design. The treatments were Control (ruminal bicarbonate buffer with [mmol/kg]: acetate = 72; propionate = 30; isobutyrate = 2.1; butyrate = 12; valerate = 1.2; caproate = 0; and heptanoate = 0); Val (same as control except for valerate = 8 mmol/kg); Cap (same as control except for caproate = 3.5 mmol/kg); and Hep (same as control except for heptanoate = 3 mmol/kg). All buffers were incubated for 90 min in the rumen, and ruminal VFA absorption rates were maintained by continuous intraruminal infusion of VFA. The arterial concentrations of valerate and heptanoate showed a small increase (< or = 1 micromol/L; P < 0.05) with inclusion of the respective acid in the ruminal buffer, but no change (P = 0.57) in arterial concentration of caproate was detected. Valerate increased (P < 0.05) the net portal flux of butyrate and valerate, as well as the net splanchnic flux of propionate, butyrate, and valerate. With Cap and Hep, the net portal flux of caproate and heptanoate accounted for 54 and 45% of ruminal disappearance rates, respectively, indicating that these acids were extensively metabolized by the ruminal epithelium. Caproate was ketogenic both in the ruminal epithelium and in the liver, and Cap increased (P < 0.05) the arterial concentration, ruminal vein minus arterial concentration difference, net hepatic flux, and net splanchnic flux of 3-hydroxybutyrate. The net hepatic flux of glucose decreased (P = 0.02) with Cap and Hep compared with Control and Val; however, no effect (P = 0.14) on the net splanchnic flux of glucose could be detected. We conclude that the strong biological activity of valerate, caproate, and heptanoate warrant increased emphasis on monitoring their ruminal presence and their potential systemic effects on ruminant metabolism.  相似文献   

12.
Hypoglycemia is a common complication of virulent canine babesiosis. A study was conducted to determine the prevalence of and potential risk factors for hypoglycemia in canine babesiosis from Babesia canis rossi. Plasma glucose concentration was measured at presentation in 250 dogs with babesiosis, of which 111 were admitted to hospital. The prevalence of hypoglycemia (<60 mg/dL) was 9% (23/250). Twenty-two hypoglycemic dogs required admission, making the prevalence of hypoglycemia in admitted dogs 19.8%. Sixteen dogs had severe hypoglycemia (<40 mg/dL), of which 5 had glucose < 18 mg/dL. Hyperglycemia (>100 mg/dL) was present in 38 dogs, of which 21 were admitted. Risk factors for hypoglycemia identified by univariate analysis were collapsed state (P < .00001), severe anemia (P = .0002), icterus (P = .003), age < 6 months (P = .02), and vomiting (P = .03). After logistic regression analysis, collapsed state (odds ratio [OR] = 18; 95% CI, 1.9-171; P = .01) and young age (OR = 2.8; 95% CI, 0.8-9.7; P = .1) remained significantly associated with hypoglycemia. Toy breeds and pregnant bitches were not at higher risk for hypoglycemia than other dogs. Blood glucose concentration should ideally be measured in all dogs requiring inpatient treatment for babesiosis but is mandatory in collapsed dogs; puppies; and dogs with severe anemia, vomiting, or icterus. Many dogs have probably been misdiagnosed with cerebral babesiosis in the past, and hypoglycemia should be suspected in any dog with coma or other neurological signs.  相似文献   

13.
We studied risk factors and characteristics of canine transmissible venereal tumours (TVTs) in Grenada. We abstracted data for 38 TVT cases and 114 TVT-free dogs submitted to a veterinary diagnostic laboratory between 2003 and 2006. Occurrence profiles, odds ratios (ORs), and logistic regression models for TVT were determined using a significance level of α = 0.05. TVT was found in 20 (52.6%) female and 18 (47.4%) male dogs. Of the TVT cases, 32 (84.2%) were between 1 and 7 years old, 20 (52.6%) were mixed breeds of dogs, 14 (36.8%) were Grenadian pothounds, while 4 (10.6%) were pure-bred dogs. Characteristic TVT lesions were genital growths [OR = 96.7; 95% CI (27,461), P < 0.001], genital bleeding [OR = 12.7; 95% CI (4.6, 39.2), P < 0.001] and secondary inflammation of TVT lesion [OR = 4.3; 95% CI (2, 10), P < 0.001]. Extragenital TVT lesions were observed in 23% (9/38) of dogs. An increased risk for TVT was associated with age as adult (1–7 years) dogs [OR = 12; 95% CI (1.6, 94), P < 0.001] and status as a Grenadian pothound [OR = 8.6; 95% CI (3, 25), P < 0.001]. Clinicians should educate dog owners about increased risk of TVT for Grenadian pothounds and consider TVT as a possibility for some extragenital tumours.  相似文献   

14.
Acetate, propionate, and butyrate were intraruminally administered to dry feed-fed suckling calves to evaluate their effects on plasma ketone bodies, anti-diuretic hormone (ADH) concentrations, and urine volume. Four male Holstein calves (5–7 weeks old) were given 1.0 L of warm water or 0.5 mole of one of the acids in 1.0 L of warm water. A 4 × 4 Latin square design was adopted for the experiment. The acetate group showed significantly higher plasma acetate concentrations than the other three groups between 0.25 h and 2.0 h after administration ( P  < 0.01). Plasma glucose concentrations did not differ markedly among the groups. The butyrate group showed significantly higher plasma ketone body concentrations than the other three groups until the end of the experiment ( P  < 0.01). Plasma ADH concentrations quickly rose in the butyrate group and remained significantly higher than in the other three groups from 0.25 h to 2.5 h after administration ( P  < 0.05). In accordance with the elevation of plasma ADH levels, the butyrate group showed decreases in urine volume and increases in urine osmolarity ( P  < 0.05). Plasma osmolarity and hematocrit values (Ht) were not different among the groups. These results suggest that the administration of acetate and propionate had little effect on ADH secretion.  相似文献   

15.
The production of propionate has been measured in the large colon of two ponies fitted with cannulas and fed on a standard diet of hay or hay and wheat bran. A continuous infusion of 14C-labelled sodium propionate was made into a cannula in the right ventral colon and samples of ingesta were obtained from another cannula near the end of the right dorsal colon. A simultaneous intravenous infusion of [2-3H]-labelled glucose was made to measure total glucose entry. Colonic propionate production on the hay diet was 146 (range 110-176) mg/h per kg body weight and, on the hay and bran, 195 (range 130-273) mg/h per kg body weight. Mean total glucose production for the two diets was 120 (range 98-143) and 92 (range 79-116) mg/h per kg body weight, respectively. The results obtained indicate that 50% of the glucose was synthesized from propionate produced in the colon in ponies on the hay diet and 61% in ponies on the hay and bran diet.  相似文献   

16.
本试验旨在研究马铃薯淀粉渣和玉米秸秆混合青贮料对肉牛瘤胃内环境及血清生化指标的影响.选择4头平均体重(455.00±19.50)kg的健康秦川杂交肉牛,随机分配到4×4拉丁方试验设计中.4组分别为:1)对照组,40％精料+60％玉米秸秆黄贮料;2)S25组,40％精料+45％玉米秸秆黄贮料+15％马铃薯淀粉渣和玉米秸秆混合青贮料;3)S50组,40％精料+30％玉米秸秆黄贮料+30％马铃薯淀粉渣和玉米秸秆混合青贮料;4)S75组,40％精料+15％玉米秸秆黄贮料+45％马铃薯淀粉渣和玉米秸秆混合青贮料.结果表明:各组肉牛平均日增重、干物质采食量和蛋白质摄入量均差异不显著(P＞0.05).S25、S50和S75组肉牛瘤胃液氨态氮浓度均高于对照组(P＞0.05),分别提高了58.96％、36.35％、26.17％.各组乙酸、丙酸、丁酸、戊酸、总挥发性脂肪酸浓度和乙酸、丙酸、丁酸、戊酸比例及乙酸/丙酸、(乙酸+丁酸)/丙酸均无显著差异(P＞0.05).各组间血清总蛋白、尿素氮和葡萄糖含量均无显著差异(P＞0.05).由此可知,马铃薯淀粉渣和玉米秸秆混合青贮料替代部分玉米秸秆黄贮料能提高肉牛瘤胃液氨态氮浓度,对瘤胃液挥发性脂肪酸含量和血清生化指标无影响.马铃薯淀粉渣和玉米秸秆混合青贮料可以替代肉牛饲粮中75％的玉米秸秆黄贮料.  相似文献   

17.
Eight horses were allotted into pairs consisting of one cecum- and right ventral colon-fistulated animal and one cecum-fistulated animal. They were fed daily at the same level of intake either a high-fiber (HF) or a high-starch (HS) diet without or with 10 g of a Saccharomyces cerevisiae preparation, in a 4 x 4 Latin square design. The HS diet provided a starch overload (i.e., 3.4 g starch x kg(-1) BW x meal(-1)) while maintaining a high amount of fiber intake (i.e., dietary NDF/starch ratio was 1.0). A 21-d period of adaptation to the treatments occurred before cecal and colonic contents were withdrawn 4 h after the morning meal to count total anaerobic, cellulolytic, and lactic acid-utilizing bacteria, lactobacilli, and streptococci. Lactic acid, volatile fatty acids, ammonia concentrations, and pH were measured on cecal and colonic fluid samples collected hourly during the first 12-h postfeeding. When the HS diet was fed, the concentration of total anaerobic and lactic acid-utilizing bacteria increased (P < 0.001), whereas that of cellulolytic bacteria decreased (P < 0.05) in the cecum. The concentration of lactobacilli and streptococci increased (P < 0.001) in the cecal and colonic contents. These alterations of the microbial profiles were associated with decreases (P < 0.001) of pH, (acetate + butyrate)/propionate ratio and with an increase (P < 0.001) of lactic acid concentration. Supplementing the S. cerevisiae preparation increased (P < 0.01) the concentration of viable yeast cells, averaging 4.3 x 10(6) and 4.5 x 10(4) cfu/mL in the cecal and colonic contents, respectively. Yeast supplementation had almost no effect on microbial counts in the cecum and colon. The supplementation of S. cerevisiae appeared to modify (P < 0.05) pH, concentrations of lactic acid and ammonia, molar percentages of acetate and butyrate with the HS diet and [(acetate + butyrate)/propionate] ratio when the HF diet was fed. The effects of the S. cerevisiae preparation were greater in the cecum than in the colon, which coincided with the abundance of yeast cells. When the digestion of starch in the small intestine was saturated, the effect of the addition of a S. cerevisiae preparation appeared to limit the extent of undesirable changes in the intestinal ecosystem of the horse.  相似文献   

18.
《African Zoology》2013,48(2):311-320
The greater cane rat is a recently domesticated monogastric herbivore, and the importance of the caecum in the functioning of its digestive tract has frequently been mentioned. However, no data are available on caecal fermentative activity of this animal and research on the digestive physiology was only performed in adult animals. The present work was initiated to describe some parameters of the digestive tract anatomy and to study caecal fermentation of the growing cane rat. Thirty 40-day-old weaned cane rats were used in this experiment. Six of them were immediately euthanased and 12 were housed in a collective pen for gastrointestinal tract (GIT) parameters measurements. Twelve others were kept in individual cages to record growth and food intake. Captive cane rats received a pelleted diet containing 12.5% of crude protein and 16.7% of lignocellulose. Six of the 12 collectively housed animals were euthanased on day 82 and a further six on day 103. The growth rate increased with age (P < 0.01) with a linear growth curve (P < 0.001) while the feed intake (g/kg body weight) did not vary (P > 0.05). The caecum represented the largest compartment of the digestive tract constituting more than 40% of total GIT contents. Acetate was the most abundant short-chain fatty acid with more than 70% of the total, followed by propionate (less than 25%) and butyrate (around 5%). Short-chain fatty acid profiles varied with age: when age increased, the acetate proportion increased (P < 0.01), the propionate proportion decreased (P < 0.001) and the butyrate proportion remained unchanged (P > 0.05). The propionate/butyrate ratio showed a decrease with an increase in age (P = 0.05). Ammonia concentrations did not vary with age (P > 0.05). It is concluded that the caecum is an important site of fermentation in the growing cane rat.  相似文献   

19.
酵母培养物对山羊瘤胃纤维素酶活及挥发性脂肪酸的影响   总被引：3，自引：1，他引：3  
在高精料日粮条件下,以4头装有永久性瘤胃瘘管的本地山羊为试验动物,采用4×4拉丁方设计,研究酵母培养物(0、20、30、和40g/d)对山羊瘤胃纤维素酶活及挥发性脂肪酸(VFA)的影响。结果表明:日粮中添加酵母培养物有提高瘤胃中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)消失率及羧甲基纤维素酶活、木聚糖酶活的趋势,但差异均不显著(P>0.05)。日粮中添加酵母培养物能够提高瘤胃乙酸、丙酸、丁酸、TVFA浓度及乙酸丙酸比。与对照组相比,早饲后4h时,20g/d处理组乙酸浓度提高22%(P<0.05),TVFA浓度提高21%(P<0.05),30g/d处理组的丙酸浓度提高11%(P>0.05);18h时,30g/d处理组乙酸浓度和TVFA浓度较对照组分别提高32%(P<0.05)和28%(P<0.05)。  相似文献   

20.
Eight mature female dogs (18.0 +/- 0.2 kg) were used in a replicated 4 x 4 Latin square experiment to determine the feeding value of low-ash poultry meal (PM) in a complete food fed to dogs. All foods contained graded concentrations of PM (10.4 to 32.5% DM), resulting in foods that were 10, 15, 20, and 25% CP. Daily DMI averaged 284 +/- 14 g/d. An increase in PM resulted in an increase in fecal moisture from 44.7 to 55.1% (linear; P < 0.01), and fecal DM output increased from 24.8 to 31.6 g/d (linear; P < 0.05). Ileal DM flow increased from 27.1 to 40.7 g/d (linear; P < 0.01). Small intestinal DM digestibility decreased from 90.4 to 86.1% (linear; P < 0.01) and total-tract DM digestibility decreased from 91.2 to 89.4% (linear; P < 0.01) as PM increased. Large intestinal DM digestibility increased from 8.4 to 21.1% with increasing PM (linear; P < 0.05). Fecal excretion of CP increased from 5.6 to 10.0 g/d (linear; P < 0.01) and ileal flow of CP increased from 6.9 to 15.6 g/d (linear; P < 0.01) as PM increased. Small intestinal CP digestibility was unaffected with treatment (P > 0.05). Large intestinal CP digestibility increased from 21.6 to 37.1% (linear; P < 0.05) with increasing PM. Total-tract CP digestibility increased from 81.0 to 86.6% (linear; P < 0.01) as PM increased. Arginine had the highest overall digestibility ranging from 88.5 to 91.3%, whereas cysteine had the lowest digestibility, ranging from 67.1 to 71.4%. These data indicate that PM is a highly digestible protein source for canine foods with inclusions of 10.4 to 32.5% of DM.  相似文献   

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