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Objective: To determine conversion formulas so that values from the HemoCue® hemoglobinometer (HbHQ) could be equated to hemoglobin concentrations measured by the gold‐standard cyanomethemoglobin (HbCY) method and used for estimation of packed cell volume (PCV) in cats. Study design: Prospective, in vitro. Animals: Twelve healthy, adult, client‐owned cats. Interventions: The PCV of 12 parent blood samples was manipulated between ~3 and ~80% by removing or adding autologous plasma. Hemoglobin was measured by the HbCY method at a university clinical pathology laboratory and by the azidemethemoglobin method in a HbHQ. PCV was determined by micro‐centrifugation. Measurements and main results: Hemoglobin varied from 1–26 g/dL. Repeated‐measures regression of HbCY on HbHQ demonstrated that the Y‐intercept was not different from zero. When the regression was repeated, forcing the line through the origin the coefficient for converting HbHQ to HbCY was not significantly different from 1.0 (adjusted R2=99.7%). The conversion formula was HbCY=HbHQ. Using similar methods, the conversion formula for estimating PCV was PCV=3.1 HbHQ (adjusted R2=99.8%). Conclusion: Hemoglobin concentration measured by the HemoCue® was indistinguishable from the (HbCY) method in feline blood over a wide range of hemoglobin concentrations. This study demonstrates that in cats PCV=3.1HbHQ. Clinical relevance: The HemoCue® is useful for point‐of‐care hemoglobinometry and for estimating PCV in cats.  相似文献   

3.
The diversity of Cryptosporidium at species, subtype family and subtype level in diarrhoeic children was investigated in four provinces in South Africa. A total of 442 stool samples from children <5 years of age were collected under a large rotavirus surveillance programme and analysed by Ziehl–Neelsen acid‐fast staining. Fifty‐four (12.2%) were positive for Cryptosporidium, of which 25 were genotyped by polymerase chain reaction (PCR)–restriction fragment length polymorphism (RFLP) and DNA sequence analyses of the 18S rRNA gene. The majority of genotyped specimens were identified as C. hominis (76%), and a high genetic diversity was found with five different C. hominis subtype families (Ia, Ib, Id, Ie and If). Cryptosporidium parvum was found in 20% of the isolates, and three subtype families were identified (IIc, IIe and IIb), with subtype family IIc being the most common. One specimen was identified as C. meleagridis of the subtype family IIId. These results are in accordance with findings from other developing countries and report for the first time the presence in South Africa of C. meleagridis, various subtypes of C. parvum and the subtype family Ie of C. hominis. The results suggest that C. hominis and anthroponotic C. parvum subtypes are the major cause of cryptosporidiosis in South Africa. Further molecular studies are needed to better understand the epidemiology and public health importance of Cryptosporidium in humans in South Africa.  相似文献   

4.
Over 250 individuals fell ill in five outbreaks caused by Cryptosporidium parvum in Finland, October–November 2012. The cases were connected by lunch meals at restaurants in four different cities. In two outbreaks, the same C. parvumIIdA17G1 subtype was found in patients’ stool samples which supports a single source of infection. Frisée salad was the only common food item served at the restaurants, and consumption of lunch salad containing the frisée salad was associated with the illness. Lunch customers who responded that they had eaten lunch salad were three times more likely to have become ill than those who had not answered whether they had eaten the salad or not (RR 2.66; 95% Cl 1.02–6.9, P‐value <0.01). Cryptosporidiosis should be considered as a causal agent in long‐lasting watery diarrhoea combined with abdominal cramps, and clinical samples should be tested for Cryptosporidium at the same time bacteria and viruses are tested. Measures to prevent contamination of ‘ready‐to‐eat vegetables’ with Cryptosporidium oocysts and methods to test frozen food samples should be developed.  相似文献   

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The aim of this study was to determine the prevalence, variability with host age, and the genotypes of species of Cryptosporidium in cattle from 15 dairy farms in Qazvin province, Iran. Fecal samples, collected from 272 cattle during May 2006 to December 2007, were characterized microscopically. Oocysts from 51 positive samples were analyzed using PCR assay of 18S SSU rRNA, restriction fragment length polymorphism (RFLP) and sequencing. We identified 72.6% of the positive samples as Cryptosporidium parvum, 17.7% as Cryptosporidium andersoni, 7.8% as Cryptosporidium bovis and 1.9% as a novel genotype of C. parvum possessing a single mutation on MboII restriction. An infection rate of 19.5% of C. parvum among 174 pre-weaned calves was significantly higher than the 3.1% among 98 post-weaned calves (P < 0.0006). This is the first report of C. bovis and the new subgenotype of C. parvum in Iranian cattle.  相似文献   

7.
The combined antibacterial effects of tilmicosin (TIL) and florfenicol (FF) against Actinobacillus pleuropneumoniae (APP) (n = 2), Streptococcus suis (S. suis) (n = 2), and Haemophilus parasuis (HPS) (n = 2) were evaluated by chekerboard test and time‐kill assays. The pharmacokinetics (PKs) of TIL‐ and FF‐loaded hydrogenated castor oil (HCO)‐solid lipid nanoparticles (SLN) were performed in healthy pigs. The results indicated that TIL and FF showed synergistic or additive antibacterial activities against APP, S. suis and HPS with the fractional inhibitory concentration (FIC) ranging from 0.375 to 0.75. The time‐kill assays showed that 1/2 minimum inhibitory concentration (MIC) TIL combined with 1/2 MIC FF had a stronger ability to inhibit the growth of APP, S. suis, and HPS than 1 MIC TIL or 1 MIC FF, respectively. After oral administration, plasma TIL and FF concentrations could maintain about 0.1 μg/ml for 192 and 176 hr. The SLN prolonged the last time point with detectable concentrations (Tlast), area under the concentration–time curve (AUC0‐t), elimination half‐life (T½ke), and mean residence time (MRT) by 3.1, 5.6, 12.7, 3.4‐fold of the active pharmaceutical ingredient (API) of TIL and 11.8, 16.5, 18.1, 12.1‐fold of the API of FF, respectively. This study suggests that the TIL‐FF‐SLN could be a useful oral formulation for the treatment of APP, S. suis, and HPS infection in pigs.  相似文献   

8.
Soya bean agglutinin (SBA) is a glycoprotein and the main anti‐nutritional component in most soya bean feedstuffs. It is mainly a non‐fibre carbohydrate‐based protein and represents about 10% of soya bean‐based anti‐nutritional effects. In this study, we sought to determine the effects of N‐Acetyl‐D‐galactosamine (GalNAc or D‐GalNAc) on the damage induced by SBA on the membrane permeability and tight junction proteins of piglet intestinal epithelium (IPEC‐J2) cells. The IPEC‐J2 cells were pre‐cultured with 0, 0.125 × 10?4, 0.25 × 10?4, 0.5 × 10?4, 1.0 × 10?4 and 2.0 × 10?4 mmol/L GalNAc at different time period (1, 2, 4 and 8 hr) before being exposed to 0.5 mg/ml SBA for 24 hr. The results indicate that pre‐incubation with GalNAc mitigates the mechanical barrier injury as reflected by a significant increase in trans‐epithelial electric resistance (TEER) value and a decrease in alkaline phosphatase (ALP) activity in cell culture medium pre‐treated with GalNAc before incubation with SBA as both indicate a reduction in cellular membrane permeability. In addition, mRNA levels of the tight junction proteins occludin and claudin‐3 were lower in the SBA‐treated groups without pre‐treatment with GalNAc. The mRNA expression of occludin was reduced by 17.3% and claudin‐3 by 42% (p < 0.01). Moreover, the corresponding protein expression levels were lowered by 17.8% and 43.5% (p < 0.05) respectively. However, in the GalNAc pre‐treated groups, occludin and claudin‐3 mRNAs were reduced by 1.6% (p > 0.05) and 2.7% (p < 0.01), respectively, while the corresponding proteins were reduced by 4.3% and 7.2% (p < 0.05). In conclusion, GalNAc may prevent the effect of SBA on membrane permeability and tight junction proteins on IPEC‐J2s.  相似文献   

9.
ESBL/AmpC‐producing Escherichia coli is increasingly isolated from humans and animals worldwide. The occurrence of ESBL/AmpC‐producing E. coli was studied in food‐producing animals in Finland, a country with a low and controlled use of antimicrobials in meat production chain. A total of 648 cattle, 531 pig, 495 broiler and 35 turkey faecal samples were collected from four Finnish slaughterhouses to determine the presence of extended‐spectrum β‐lactamase (ESBL/AmpC)‐producing E. coli. In addition, 260 broiler and 15 turkey samples were screened for carbapenemase‐producing E. coli. Susceptibility to different class of cephalosporins and meropenem was determined with disc diffusion tests according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST). Determination of ESBL/AmpC production was performed with a combination disc diffusion test according to the recommendations of the European Food Safety Authority (EFSA). Plasmidic blaESBL/AmpC genes were characterized by polymerase chain reaction and sequencing. A collection of isolates producing AmpC enzyme but not carrying plasmidic blaAmpC was analysed by PCR and sequencing for possible chromosomal ampC promoter area mutations. Altogether ESBL/AmpC‐producing E. coli was recovered from five cattle (0.8%), eight pig (1.5%) and 40 broiler samples (8.1%). No ESBL/AmpC‐producing E. coli was found in turkey samples. Carbapenem resistance was not detected. Altogether ESBL/AmpC‐producing E. coli was found on 4 (2.0%), 3 (4.5%) and 14 (25%) cattle, pig and broiler farms, respectively. From cattle samples 3 (27%) blaCTX‐M‐1 and from broiler samples 13 (33%) blaCTX‐M‐1 and 22 (55%) blaCMY‐2 gene‐carrying isolates were detected. In pigs, no plasmidic blaESBL/AmpC gene‐carrying isolates were found. In all analysed isolates, the same mutations in the promoter region of chromosomal ampC were detected. The results showed low occurrence of ESBL/AmpC‐producing E. coli in Finnish food‐producing animals. In pigs, plasmidic blaESBL/AmpC‐carrying E. coli was not detected at all.  相似文献   

10.
The objective of this study was to test the hypothesis that aspartame supplementation in starter diet accelerates small intestinal cell cycle by stimulating secretion and expression of glucagon‐like peptide ?2 (GLP‐2) in pre‐weaned lambs using animal and cell culture experiments. In vivo, twelve 14‐day‐old lambs were selected and allocated randomly to two groups; one was treated with plain starter diet (Con, n = 6) and the other was treated with starter supplemented with 200 mg of aspartame/kg starter (APM, n = 6). Results showed that the lambs received APM treatment for 35 d had higher (p < .05) GLP‐2 concentration in the plasma and greater jejunum weight/live body weight (BW) and jejunal crypt depth. Furthermore, APM treatment significantly upregulated (p < .05) the mRNA expression of cyclin D1 in duodenum; and cyclin A2, cyclin D1, cyclin‐dependent kinases 6 (CDK6) in jejunum; and cyclin A2, cyclin D1, CDK4 in ileum. Moreover, APM treatment increased (p < .05) the mRNA expression of glucagon (GCG), insulin‐like growth factor 1 (IGF‐1) in the jejunum and ileum and mRNA expression of GLP‐2 receptor (GLP‐2R) in the jejunum. In vitro, when jejunal cells were treated with GLP‐2 for 2 hr, the 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2‐H‐tetrazolium bromide (MTT) OD, IGF‐1 concentration, and the mRNA expression of IGF‐1, cyclin D1 and CDK6 were increased (p < .05). Furthermore, IGF‐1 receptor (IGF‐1R) inhibitor decreased (p < .05) the mRNA expression of IGF‐1, cyclin A2, cyclin D1 and CDK6 in GLP‐2 treatment jejunal cells. These results suggest that aspartame supplementation in starter accelerates small intestinal cell cycle that may, in part, be related to stimulate secretion and expression of GLP‐2 in pre‐weaning lambs. Furthermore, GLP‐2 can indirectly promote the proliferation of jejunal cells mainly through the IGF‐1 pathway. These findings provide new insights into nutritional interventions that promote the development of small intestines in young ruminants.  相似文献   

11.
Heparin‐binding EGF‐like growth factor (HB‐EGF) regulates several cell functions by binding to its membrane receptor (ErbB1 and ErbB4). Experimental evidences suggest that HB‐EGF, prostaglandins (PGs) and interferon‐τ (IFN‐τ) regulate uterine function for pregnancy establishment in ruminants. In this study, the mRNA expressions of HB‐EGF, ErbB1 and ErbB4 in bovine endometrium and the effects of HB‐EGF and IFN‐τ on PGE2 and PGF2‐α production by endometrial cells were investigated. RT‐PCR analysis revealed that HB‐EGF mRNA was greater at the mid‐luteal stage than at the early and regressed luteal stages (p < 0.05). ErbB1 mRNA expression was greater at the mid‐ and late luteal stages than at the other luteal stages (p < 0.05). IFN‐τ increased the expression of HB‐EGF, ErbB1 and ErbB4 mRNA in epithelial cells (p < 0.05). HB‐EGF did not affect PGF2‐α or PGE2 production by bovine endometrial epithelial cells, but increased PGF2‐α and PGE2 production by bovine endometrial stromal cells (p < 0.05). IFN‐τ significantly decreased HB‐EGF‐stimulated PGF2‐α (p < 0.05), but not PGE2 (p > 0.05) production by stromal cells. These results indicate that HB‐EGF and its receptors expression changed in bovine endometrium throughout the oestrous cycle. IFN‐τ increased their expression in cultured endometrial cells. HB‐EGF and IFN‐τ have the ability to regulate PGs production by stromal cells and therefore may play a role in the local regulation of uterine function at the time of implantation in cattle.  相似文献   

12.
The bovine embryonic signal interferon‐τ (IFN‐τ) produced by the trophoblast is known to pass through the uterine fluid towards the endometrium and further into the maternal blood, where IFN‐τ induces specific expression of interferon‐stimulated gene expression (ISG), for example in peripheral leucocytes. In sheep, it was shown experimentally by administration of IFN‐τ that ISG is also detectable in the liver. The objective was to test whether ISG can be detected in liver biopsy specimens from Holstein–Friesian heifers during early pregnancy. Liver biopsies were taken on day 18 from pregnant and non‐pregnant heifers (n = 19), and the interferon‐stimulated protein 15 kDa (ISG‐15) and myxovirus‐resistance protein‐1 (MX‐1) gene expression was detected. The expression of both MX‐1 (p: 24.33 ± 7.40 vs np: 9.00 ± 4.02) and ISG‐15 (p: 43.73 ± 23.22 vs 7.83 ± 3.63) was higher in pregnant compared to non‐pregnant heifers (p < 0.05). In conclusion, pregnancy induced ISG‐15 and MX‐1 gene expression in the liver already at day 18 in cattle.  相似文献   

13.
Interferon‐τ (IFN‐τ) has been recognized as the primary embryonic signal responsible for maternal recognition of pregnancy. Uterine endometrium produces both prostaglandin F2α (PGF2α) and prostaglandin E2 (PGE2). PGF2α is responsible for the luteolysis; however, PGE2 favours establishment of pregnancy by its luteoprotective action. In this study, the dose‐response effect of recombinant bovine IFN‐τ (rbIFN‐τ) on prostaglandin (PG) production by buffalo endometrial stromal cells cultured in vitro was studied. Buffalo endometrial stromal cells were isolated by double enzymatic digestion, initially with trypsin III followed by a cocktail of trypsin III, collagenase type II and DNase I and subsequently cultured till confluence. Further, cells were treated with different doses of rbIFN‐τ (0.001, 0.01, 0.1, 1.0 and 10 μg/ml) and keeping a separate set of control. Culture supernatant was collected after 6, 12 and 24 h of treatment. PG levels in the culture supernatant were measured by enzyme immune assay (EIA) and total cellular protein estimated by Bradford method. Results indicated that buffalo endometrial stromal cells following rbIFN‐τ treatment enhanced the secretion of both PGE2 and PGF2α, and also its ratio in a strict dose‐dependent manner with a significant increase (p < 0.01) in PGE2 production at 1 μg/ml dose of rbIFN‐τ and maximal stimulation for both PG was observed at 10 μg/ml. Further, both PG production and its ratio were increased significantly (p < 0.01) in a time‐dependent fashion in all the groups at 6, 12 and 24 h post‐treatment with highest level achieved at 24 h as compared with control. Absolute levels of PGE2 remained higher than PGF2α indicating PGE2 as the major PG produced by endometrial stromal cells. The dose‐dependent response of rbIFN‐τ signifies the importance of optimum concentration of IFN‐τ for the embryonic development especially during the critical period to establish successful pregnancy.  相似文献   

14.
This study was to investigate the effects of Epigallocatechin‐3‐gallate (EGCG) on intestinal morphology, antioxidant capacity and anti‐inflammatory response in heat‐stressed broiler. A total of 192 2‐week‐old Arbour Acres broilers chickens were divided into four groups with six replicates per group and eight chickens per replicate: one thermoneutral control group (28°C, group TN), which was fed the basal diet; and three cyclic high‐temperature groups (35°C from 7:00 to 19:00 hr; 28°C from 19:00 hr to 7:00 hr, heat stress group), which were fed the basal diet supplementation with EGCG 0 mg/kg (group HS0), 300 mg/kg (group HS300) and 600 mg/kg (group HS600). The gut morphology and intestinal mucosal oxidative stress indicators, as well as intestinal barrier‐related gene expression, were analysed. The results showed that compared with group TN, heat stress reduced the villus height (VH), activities of glutathione peroxidase (GSH‐Px), superoxide dismutase (SOD)and catalase (CAT), increased the crypt depth (CD) and malondialdehyde (MDA)content at 21, 28 and 35 days (p < 0.05). After the heat‐stressed broilers were supplemented with EGCG, VH, VH/CD (V/C), and the activities of GSH‐Px, SOD and CAT were increased, and CD and MDA content were reduced compared with those in group HS0 without EGCG supplementation at 21, 28 and 35 days (p < 0.05). The EGCG supplementation promoted the gene expression of nuclear factor‐erythroid 2‐related factor 2 (Nrf2), Claudin‐1, Mucin 2 (Muc2) and alleviated the nuclear factor‐kappa B (NF‐κB) and lipopolysaccharide‐induced tumour necrosis factor (LITAF) gene expression compared with group HS0 (p < 0.05). Moreover, intestinal morphology was strongly correlated with antioxidant ability and inflammatory response. In conclusion, EGCG alleviated the gut oxidative injury of heat‐stressed broilers by enhancing antioxidant capacity and inhibiting inflammatory response.  相似文献   

15.
Invasive procedures in animals are challenging for veterinary students who may perceive a gynaecological examination of mares as stressful. Simulator‐based training may reduce stress. In this study, students received equine gynaecology training 4 times either on horses (group H; n = 14) or a teaching simulator (group SIM; n = 13). One day and 14 days thereafter, their diagnostic skills were tested on horses (skills tests 1 and 2). During the skills tests, the students’ stress response was analysed by heart rate, heart rate variability (HRV) parameters SDRR (standard deviation of beat‐to‐beat [RR] interval) and RMSSD (root‐mean‐square of successive RR differences), and salivary cortisol. In addition, students answered a questionnaire on their perceived stress. Sympathetic activation with increased heart rate (p < 0.001) occurred in both skills tests. In test 1, this increase was more pronounced in SIM than in H students (time × group p < 0.01). HRV decreased in students of both groups (p < 0.001). In skills test 1, this decrease was more pronounced for SIM than for H students (between groups and time × group p < 0.01 for SDRR and p < 0.05 for RMSSD). High cortisol concentrations before the skills tests may indicate an anticipatory stress response. Subjective stress perception of students was higher in skills test 1 vs 2 (p < 0.01). In skills test 2, H students felt more stressed than SIM students (p < 0.01). Self‐assessment thus differed from physiological stress parameters. In conclusion, gynaecological examination of mares evoked a moderate stress response in veterinary students, which was more evident after simulator‐based than animal‐based training.  相似文献   

16.
Post‐weaning multisystemic wasting syndrome (PMWS) and porcine dermatitis and nephropathy syndrome (PDNS) are two recently described conditions of pigs at the late nursery and fattening stages. The aim of this short communication was to describe the first reported occurrence of these conditions and of porcine circovirus type 2 (PCV2) infection in Greece. The clinical signs, gross post‐mortem changes and histopathological changes observed in affected pigs, were similar to those previously described for both PDNS and PMWS. As in previous reports, the lesions were associated with PCV2 infection, which was demonstrated by immunohistochemical and in situ hybridization methods.  相似文献   

17.
This study aims to investigate the role of matrix metalloproteinases (MMPs) in determining semen quality and to evaluate the expression and cellular localization of MMP‐2, MMP‐9, tissue inhibitor of metalloproteinase‐1 (TIMP‐1) and TIMP‐2 in the testes, epididymis and ejaculated spermatozoa. Gelatinase activities between normal (n = 21) and abnormal (n = 25) semen samples showed a significant, sixfold increase in proMMP‐2 and MMP‐2 activity in high than low sperm concentration samples (p < 0.001). ProMMP‐9 and MMP‐9 levels were significantly elevated in samples with low sperm counts compared to those with high sperm density (p < 0.001). High levels of proMMP‐2 and MMP‐2 were associated with high sperm motility (≥70%, p < 0.001). Sperm‐rich fraction showed significantly (eight‐fold) higher proMMP‐9 enzymatic activity compared with prostatic fraction. The mRNA expressions of MMP‐2, MMP‐9, TIMP‐1 and TIMP‐2 were confirmed in testicular and epididymal tissues. Immunohistochemical staining illustrated the MMP‐2‐specific strong immunoreactivity in the head of mature spermatids during spermatogenesis, whereas MMP‐9, TIMP‐1 and TIMP‐2 were absent in these cells. Matrix metalloproteinase‐9 immunoreactivity was observed in the spermatocyte and round spermatid, whereas TIMP‐1 was only exhibited in the residual bodies. Immunolabeling of epididymal and ejaculated sperm demonstrated MMP‐2 localization along acrosomal region of sperm, while MMP‐9, TIMP‐1 and TIMP‐2 localization was merely limited to the flagella. In conclusion, spermatozoa initially acquire MMP‐2 during their formation at testicular level, and the presence of this protein persists through the epididymal transit and up to ejaculate. The enzymatic activity of MMP‐2 and MMP‐9 may serve as an alternative biomarker in determining semen quality.  相似文献   

18.
The aim of this study was to identify factors that regulate ruminal epithelial insulin‐like growth factor‐binding protein (IGFBP) expression and determine its role in rumen epithelial cell proliferation. Primary bovine rumen epithelial cells (BREC) were incubated with short‐chain fatty acids (SCFAs) at pH 7.4 or 5.6, lactate, lipopolysaccharide (LPS), insulin‐like growth factor‐I (IGF‐I), ‐II (IGF‐II), or recombinant bovine IGFBP2 (rbIGFBP2). The mRNA expression levels of IGFBP in BREC were analyzed using quantitative real‐time polymerase chain reaction (qRT‐PCR). The proliferation rate of BREC was analyzed using a WST‐1 assay. IGFBP2 gene expression tended to be lower with SCFA treatment (p < .1), and IGFBP6 gene expression was significantly lower with SCFA treatment (p < .05). IGFBP3 and IGFBP6 gene expression tended to be higher with d ‐Lactate treatment (p < .1). IGFBP3 gene expression was significantly higher (p < .05) with LPS treatment. BREC treated with IGF‐I grew more rapidly than vehicle control‐treated cells (p < .01); however, recombinant bovine rbIGFBP2 inhibited IGF‐I‐induced proliferation. IGF‐II and/or rbIGFBP2 did not affect BREC proliferation. Taken together, SCFA treatment decreased IGFBP2 and IGFBP6 expression in rumen epithelial cells, and lower expression of these IGFBP might promote rumen epithelial cell proliferation by facilitating IGF‐I.  相似文献   

19.
Post-weaning Multisystemic Wasting Syndrome (PMWS) has been identified in most swine-producing countries worldwide. The disease has resulted in significant health challenges and economic damage to the swine industry. The aim of this study was to determine horizontal transmission of porcine circovirus type 2 (PCV2) and to examine viral dynamics in pigs in a controlled PMWS transmission study. In the study pigs from PMWS-affected herds and non-affected herds were permitted to have close contact (same pen), nose-to-nose contact (to pigs in neighbouring pens) or no physical contact (pen across the aisle and pens in other compartments). By DNA sequence analysis, eight variants of genotype PCV-2b were identified in the research facility. From the spread of these PCV2-variants it was concluded that PCV2 primarily infects through close contact and nose-to-nose contact. PCV2 genome sequences were obtained from selected pigs at arrival to the research facility and again when the same pigs developed PMWS. This analysis showed that pigs from PMWS-affected herds developed PMWS caused by the same variant of PCV2 as they carried when entering the research facility. In contrast, pigs from non-affected herds developed PMWS with PCV2-variants identified in pigs from PMWS-affected herds. This was probably connected to at least 103 higher mean serum-titer of PCV2 in pigs from PMWS-affected herds as compared to pigs from non-affected herds at the beginning of the transmission study. The study further showed that pigs able to control the PCV2 infection, as measured by the PCV2-titer in serum, recovered clinically (pigs from PMWS-affected herds) or stayed healthy (pigs from non-affected herds). Like this, pigs with a PCV2 titer below 5 × 108 copies/ml serum during the study period had a chance of recover from the PCV2 infection whereas pigs with PCV2 titers above 5 × 108 copies/ml serum at any time point generally died from PMWS.  相似文献   

20.
A key concern with the flooding dose technique for measuring protein synthesis is that a large dose of amino acid (AA) can potentially change the animals’ hormonal and nutritional status, which in turn can influence protein synthesis. Among stable isotope tracers, 1‐[13C]‐valine is the preferred AA for measuring protein synthesis in gut tissue and mucins. A study was conducted to determine the impact of a flooding dose of valine on the metabolic status of pigs. Six barrows [16.5 kg body weight (BW)] were randomly assigned to intravenous infusions of either 150 mm valine (1.5 mmol/kg BW) or physiological saline, following a crossover design. Blood samples were taken 10 min prior to infusion, at the end of infusion, at 10‐min intervals for 60 min post‐infusion, and at 90 and 120 min post‐infusion. Plasma concentrations of insulin, glucose, AA, urea nitrogen and packed cell volume (PCV) were measured. Infusion of valine increased plasma valine concentrations (4129 vs. 582 μm ;< 0.05) but had no influence on PCV (26.4% vs. 27.2%) and plasma concentrations of glucose (6.0 vs. 5.8 mm ) and insulin (8.2 vs. 8.5 μU/ml; > 0.10). Plasma urea nitrogen concentration was reduced with valine infusion (8.5 vs. 7.8 mg/dl; < 0.05). A flooding dose of valine had no impact on plasma concentrations of AA, and specifically branched‐chain AA such as leucine (240 vs. 231 μm ) and isoleucine (310 vs. 331 μm ;> 0.10). There was, however, a slight increase in the plasma concentrations of threonine (224 vs. 263 μm ;< 0.05) and a tendency towards reduced glycine (1387 vs. 1313 μm ;< 0.10). The results indicate that a flooding dose of valine does not cause a substantial change in the metabolic status of growing pigs and is therefore suitable for measuring protein synthesis rates.  相似文献   

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