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41.
Elemental concentrations in leaf tissue can identify limiting conditions in crops and can be useful in managing and restoring marshes. Coastal management and restoration plans frequently include Spartina spp. because they are common plants in coastal wetlands across North America. Researchers frequently compare results of stoichiometric studies among Spartina spp. to corroborate results, although their stoichiometry may not be comparable. We compare the stoichiometry of paired samples of Spartina patens and Spartina alterniflora collected across Louisiana. Overall differences in stoichiometry between species, seasonal changes, and effects of porewater chemistry were quantified. Manganese (Mn) concentrations and calcium (Ca) concentrations were higher in S. alterniflora and the difference in [Ca] increased seasonally. Sodium concentrations were similar, except during prolonged inundation. Short flooding durations decreased carbon (C):nitrogen (N) without increasing [Mn] or flooding stress in both species. 相似文献
42.
?sa Lundberg Ann Nyman Helle Ericsson Unnerstad Karin Persson Waller 《Acta veterinaria Scandinavica》2014,56(1)
Background
Streptococcus dysgalactiae and Streptococcus uberis are common causes of clinical mastitis (CM) in dairy cows. In the present study genotype variation of S. dysgalactiae and S. uberis was investigated, as well as the influence of bacterial species, or genotype within species, on the outcome of veterinary-treated CM (VTCM). Isolates of S. dysgalactiae (n = 132) and S. uberis (n = 97) were genotyped using pulsed-field gel electrophoresis. Identical banding patterns were called pulsotypes. Outcome measurements used were cow composite SCC, milk yield, additional registered VTCMs and culling rate during a four-month follow-up period.Results
In total, 71 S. dysgalactiae pulsotypes were identified. Nineteen of the pulsotypes were isolated from more than one herd; the remaining pulsotypes were only found once each in the material. All S. uberis isolates were of different pulsotypes. During the follow-up period, the SCC of S. dysgalactiae-cows was significantly lower than the SCC of S. uberis-cows (P <0.05). Median SCC of S. dysgalactiae-cows was 71 500 cells/ml and of S. uberis-cows 108 000 cells/ml. No other differences in outcome parameters could be identified between species or genotypes.Conclusions
Identical S. dysgalactiae genotypes were isolated from more than one herd, suggesting some spread of this pathogen between Swedish dairy herds. The genetic variation among S. uberis isolates was substantial, and we found no evidence of spread of this pathogen between herds. The milk SCC was lower during the follow-up period if S. dysgalactiae rather than S. uberis was isolated from the case, indicating differences in treatment response between bacterial species.Electronic supplementary material
The online version of this article (doi:10.1186/s13028-014-0080-0) contains supplementary material, which is available to authorized users. 相似文献43.
Management practices associated with udder health of first-parity dairy cows in early lactation 总被引:2,自引:0,他引:2
Nyman AK Emanuelson U Gustafsson AH Persson Waller K 《Preventive veterinary medicine》2009,88(2):138-149
This study aimed at investigating associations between management routines including feeding, housing, and milking around calving, and udder health of first-parity cows in early lactation in Swedish large, high producing, low bulk-milk somatic cell count (SCC) dairy herds housed in free stalls. Seventy-two dairy herds participated and data concerning 1189 first-parity cows calving during the study period (October 2005-January 2006) was collected. Multivariable regression analysis were performed with three different outcomes; within-herd number of first-parity cows veterinary treated for clinical mastitis at days -10 to 60 after calving, within-herd number of first-parity cows with a SCC> or =200,000cells/mL at first test-day, and SCC of first-parity cows at first test-day. Cow factors significantly associated with good udder health of first-parity cows (few cases of clinical mastitis and or low SCC) were being of the Swedish Red breed, having a high milk yield at first test-day, and a milk-urea > or =5mmol/L at first test-day. Herd factors significantly associated with good udder health were having mattresses as flooring in the cubicles in the lactating cow housing, and to house the first-parity cows in tie stalls 1 month before calving. Cow factors significantly associated with poor udder health of first-parity cows were having a milk-urea <4mmol/L at first test-day. Herd factors significantly associated with poor udder health of first-parity cows were feeding first-parity cows sugar-beet pulp or corn silage, and to give silage from a different batch to pregnant heifers than to lactating cows. Moreover, to have sawdust or shavings in the calving pen, to be moved from the calving pen > or =2 days after calving, to milk first-parity cows at the calving site instead of in the parlor, and to rinse, clean or disinfect milking units before a first-parity cow was milked were also significantly associated with poor udder health of first-parity cows. The results indicate that different control measures must be taken depending on the nature of the udder health problem. 相似文献
44.
G?rel Nyman Stina Marntell Anna Edner Pia Funkquist Karin Morgan G?ran Hedenstierna 《Acta veterinaria Scandinavica》2009,51(1):22
Background
Sedation with α2-agonists in the horse is reported to be accompanied by impairment of arterial oxygenation. The present study was undertaken to investigate pulmonary gas exchange using the Multiple Inert Gas Elimination Technique (MIGET), during sedation with the α2-agonist detomidine alone and in combination with the opioid butorphanol.Methods
Seven Standardbred trotter horses aged 3–7 years and weighing 380–520 kg, were studied. The protocol consisted of three consecutive measurements; in the unsedated horse, after intravenous administration of detomidine (0.02 mg/kg) and after subsequent butorphanol administration (0.025 mg/kg). Pulmonary function and haemodynamic effects were investigated. The distribution of ventilation-perfusion ratios (VA/Q) was estimated with MIGET.Results
During detomidine sedation, arterial oxygen tension (PaO2) decreased (12.8 ± 0.7 to 10.8 ± 1.2 kPa) and arterial carbon dioxide tension (PaCO2) increased (5.9 ± 0.3 to 6.1 ± 0.2 kPa) compared to measurements in the unsedated horse. Mismatch between ventilation and perfusion in the lungs was evident, but no increase in intrapulmonary shunt could be detected. Respiratory rate and minute ventilation did not change. Heart rate and cardiac output decreased, while pulmonary and systemic blood pressure and vascular resistance increased. Addition of butorphanol resulted in a significant decrease in ventilation and increase in PaCO2. Alveolar-arterial oxygen content difference P(A-a)O2 remained impaired after butorphanol administration, the VA/Q distribution improved as the decreased ventilation and persistent low blood flow was well matched. Also after subsequent butorphanol no increase in intrapulmonary shunt was evident.Conclusion
The results of the present study suggest that both pulmonary and cardiovascular factors contribute to the impaired pulmonary gas exchange during detomidine and butorphanol sedation in the horse. 相似文献45.
Medetomidine (0.02-0.06 mg/kg) in combination with zolazepam-tiletamine (0.8-2.3 mg/kg) were evaluated for reversible anesthesia in four species of Southeast Asian primates: Bornean orangutan (Pongo pygmaeus pygmaeus), Bornean gibbon (Hylobates muelleri), long-tailed macaque (Macaca fascicularis), and pig-tailed macaque (Macaca nemestrina). Twenty-three anesthetic procedures of captive-held and free-ranging primates were studied in Sabah, Malaysia. The induction was smooth and rapid. Respiratory and heart rates were stable throughout anesthesia, whereas body temperature and systolic arterial blood pressure decreased significantly. Atipamezole at five times the medetomidine dose effectively reversed anesthesia, with first signs of recovery within 3-27 min. 相似文献
46.
Anna Edner DVM Görel Nyman DVM PhD Diplomate ECVA & Birgitta Essén-Gustavsson PhD 《Veterinary anaesthesia and analgesia》2002,29(4):182-199
Objectives To study in horses (1) the relationship between cardiovascular variables and muscle perfusion during propofol–ketamine anaesthesia, (2) the physiological effects of a single intravenous (IV) detomidine injection, (3) the metabolic response of muscle to anaesthesia, and (4) the effects of propofol–ketamine infusion on respiratory function. Study design Prospective experimental study. Animals Seven standardbred trotters, 5–12 years old, 416–581 kg. Methods Anaesthesia was induced with intravenous (IV) guaifenesin and propofol (2 mg kg?1) and maintained with a continuous IV infusion of propofol (0.15 mg kg?1 minute?1) and ketamine (0.05 mg kg?1 minute?1) with horses positioned in left lateral recumbency. After 1 hour, detomidine (0.01 mg kg?1) was administered IV and 40–50 minutes later anaesthesia was discontinued. Cardiovascular and respiratory variables (heart rate, cardiac output, systemic and pulmonary artery blood pressures, respiratory rate, tidal volume, and inspiratory and expiratory O2 and CO2) and muscle temperature were measured at pre‐determined times. Peripheral perfusion was measured continuously in the gluteal muscles and skin using laser Doppler flowmetry (LDF). Muscle biopsy samples from the left and right gluteal muscles were analysed for glycogen, creatine phosphate, creatine, adenine nucleotides, inosine monophosphate and lactate. Arterial blood was analysed for PO2, PCO2, pH, oxygen saturation and HCO3. Mixed venous blood was analysed for PO2, PCO2, pH, oxygen saturation, HCO3, cortisol, lactate, uric acid, hypoxanthine, xanthine, creatine kinase, creatinine, aspartate aminotransferase, electrolytes, total protein, haemoglobin, haematocrit and white blood cell count. Results Circulatory function was preserved during propofol–ketamine anaesthesia. Detomidine caused profound hypertension and bradycardia and decreased cardiac output and muscle perfusion. Ten minutes after detomidine injection muscle perfusion had recovered to pre‐injection levels, although heart rate and cardiac output had not. No difference in indices of muscle metabolism was found between dependent and independent muscles. Anaerobic muscle metabolism, indicated by decreased muscle and creatine phosphate levels was evident after anaesthesia. Conclusion Muscle perfusion was closely related to cardiac output but not arterial blood pressure. Total intravenous anaesthesia with propofol–ketamine deserves further study despite its respiratory depression effects, as the combination preserves cardiovascular function. Decreases in high‐energy phosphate stores during recovery show that muscle is vulnerable after anaesthesia. Continued research is required to clarify the course of muscle metabolic events during recovery. 相似文献
47.
Ylva Persson Ann-Kristin J Nyman Ulrika Gr?nlund-Andersson 《Acta veterinaria Scandinavica》2011,53(1):36
Background
A nationwide survey on the microbial etiology of cases of subclinical mastitis in dairy cows was carried out on dairy farms in Sweden. The aim was to investigate the microbial panorama and the occurrence of antimicrobial resistance. Moreover, differences between newly infected cows and chronically infected cows were investigated.Methods
In total, 583 quarter milk samples were collected from 583 dairy cows at 226 dairy farms from February 2008 to February 2009. The quarter milk samples were bacteriological investigated and scored using the California Mastitis Test. Staphylococci were tested for betalactamase production and presence of resistance was evaluated in all specific udder pathogens. Differences between newly infected cows and chronically infected cows were statistically investigated using logistic regression analysis.Results
The most common isolates of 590 bacteriological diagnoses were Staphylococcus (S) aureus (19%) and coagulase-negative staphylococci (CNS; 16%) followed by Streptococcus (Str) dysgalactiae (9%), Str. uberis (8%), Escherichia (E.) coli (2.9%), and Streptococcus spp. (1.9%). Samples with no growth or contamination constituted 22% and 18% of the diagnoses, respectively. The distribution of the most commonly isolated bacteria considering only bacteriological positive samples were: S. aureus - 31%, CNS - 27%, Str. dysgalactiae - 15%, Str. uberis - 14%, E. coli - 4.8%, and Streptococcus spp. - 3.1%. There was an increased risk of finding S. aureus, Str. uberis or Str. dysgalactiae in milk samples from chronically infected cows compared to findings in milk samples from newly infected cows. Four percent of the S. aureus isolates and 35% of the CNS isolates were resistant to penicillin G. Overall, resistance to other antimicrobials than penicillin G was uncommon.Conclusions
Staphylococcus aureus and CNS were the most frequently isolated pathogens and resistance to antimicrobials was rare. 相似文献48.
Colonic fermentation of dietary fiber produces carboxylic acids and may stimulate the growth of beneficial bacteria. This study investigated how byproducts of wheat processing (distillers' grains and two fractions from the wet fractionation to starch and gluten, one of which was treated with xylanase) affect the composition of the cecal microbiota and the formation of carboxylic acids in rats. Differences were mostly found between diets based on supernatants and pellets, rather than between fiber sources. Cecal pools and levels of most carboxylic acids in portal blood were higher for rats fed the supernatant diets, while cecal pH and ratios of acetic to propionic acid in portal blood were lower. The diet based on supernatant from distillers' grains gave the highest level of bifidobacteria. Molecular weight and solubility are easier to modify with technological processes, which provides an opportunity to optimize these properties in the development of health products. 相似文献
49.
Tamara Grubb Anna Edner Jan HM Frendin Pia Funkquist Anneli Rydén Görel Nyman 《Veterinary anaesthesia and analgesia》2013,40(6):e9-e18
ObjectiveTo assess oxygenation, ventilation‐perfusion (V/Q) matching and plasma endothelin (ET‐1) concentrations in healthy horses recovering from isoflurane anaesthesia administered with or without pulse‐delivered inhaled nitric oxide (iNO).Study DesignProspective experimental trial.AnimalsHealthy adult Standardbred horses.MethodsHorses were anaesthetized with isoflurane in oxygen and placed in lateral recumbency. Six control (C group) horses were anaesthetized without iNO delivery and six horses received pulse‐delivered iNO (NO group). After 2.5 hours of anaesthesia isoflurane and iNO were abruptly discontinued, inhaled oxygen was reduced from 100% to approximately 30%, and the horses were moved to the recovery stall. At intervals during a 30‐minute period following the discontinuation of anaesthesia, arterial and mixed venous blood gas values, shunt fraction (Qs/Qt), plasma ET‐1 concentration, pulse rate and respiratory rate were measured or calculated. Repeated measures anova and a Bonferroni post hoc test was used to analyze data with significance set at p <0.05.ResultsAt all time points in the recovery period, NO horses maintained better arterial oxygenation (oxygen partial pressure: NO 13.2 ± 2.7–11.1 ± 2.7 versus C 6.7 ± 1.1–7.1 ± 1.1 kPa) and better V/Q matching (Qs/Qt NO 0.23 ± 0.05–0.14 ± 0.06 versus C 0.48 ± 0.03–0.32 ± 0.08%) than C horses. Mixed venous oxygenation was higher in NO for 25 minutes following the discontinuation of anaesthesia (NO 6.3 ± 0.2–4.5 ± 0.07 versus C 4.7 ± 0.6–3.7 ± 0.3 kPa). In both groups of horses arterial oxygenation remained fairly stable; venous oxygenation declined over this time period in the NO group but still remained higher than venous oxygen in the C group. ET‐1 concentrations were higher at most time points in C than NO. Changes in other parameters were either minor or absent.Conclusions and Clinical RelevanceDelivery of iNO to healthy horses during anaesthesia results in better arterial and venous oxygenation and V/Q matching (as determined by lower Qs/Qt) and lower ET‐1 concentrations throughout a 30‐minute anaesthetic recovery period. 相似文献
50.
Kerstin de Verdier Ann Nyman Christina Greko Bj?rn Bengtsson 《Acta veterinaria Scandinavica》2012,54(1):2