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31.
The objective of this study was to investigate epidemiological risk factors for porcine non-specific colitis (NSC). Forty-seven Scottish pig farms, with and without a clinical history of diarrhoea during the growing period (15-40 kg), were selected. The study included farm visits, clinical inspection of pigs, completion of farm management questionnaires, pathological tests into the cause of the diarrhoea and analysis of the non-starch polysaccharide (NSP) content of feeds. The results from 17 farms designated as NSC and 10 control farms suggest dietary associations with NSC. Farms with NSC fed diets with significantly higher levels of NSPs, especially containing the sugars glucose, arabinose and xylose. Few management factors were identified, although the high prevalence of infectious colitis reduced the power of the study.  相似文献   
32.
We used a novel digital autoradiographic technique that enabled, for the first time, simultaneous visualization and quantification of spatial and temporal changes in carbon allocation patterns in ectomycorrhizal mycelia. Mycorrhizal plants of Pinus sylvestris L. were grown in microcosms containing non-sterile peat. The time course and spatial distribution of carbon allocation by P. sylvestris to mycelia of its mycorrhizal partners, Paxillus involutus (Batsch) Fr. and Suillus bovinus (L.): Kuntze, were quantified following 14C pulse labeling of the plants. Litter patches were used to investigate the effects of nutrient resource quality on carbon allocation. The wood-decomposer fungus Phanerochaete velutina (D.C.: Pers.) Parmasto was introduced to evaluate competitive and territorial interactions between its mycelial cords and the mycelial system of S. bovinus. Growth of ectomycorrhizal mycelium was stimulated in the litter patches. Nearly 60% of the C transferred from host plant to external mycorrhizal mycelium (> 2 mm from root surfaces) was allocated to mycelium in the patches, which comprised only 12% of the soil area available for mycelial colonization. Mycelia in the litter patch most recently colonized by mycorrhizal mycelium received the largest investment of carbon, amounting to 27 to 50% of the total 14C in external mycorrhizal mycelium. The amount of C transfer to external mycelium of S. bovinus following pulse labeling was reduced from a maximum of 167 nmol in systems with no saprotroph to a maximum of 61 nmol in systems interacting with P. velutina. The 14C content of S. bovinus mycelium reached a maximum 24-36 h after labeling in control microcosms, but allocation did not reach a peak until 56 h after labeling, when S. bovinus interacted with mycelium of P. velutina. The mycelium of S. bovinus contained 9% of the total 14C in the plants (including mycorrhizae) at the end of the experiment, but this was reduced to 4% in the presence of P. velutina. The results demonstrate the dynamic manner in which mycorrhizal mycelia deploy C when foraging for nutrients. The inhibitory effect of the wood-decomposer fungus P. velutina on C allocation to external mycorrhizal mycelium has important implications for nutrient cycling in forest ecosystems.  相似文献   
33.
OBJECTIVE: To evaluate the use of systemic disease signs for classifying severity of acute coliform mastitis in dairy cows. DESIGN: Prospective cohort study. ANIMALS: 144 dairy cows. PROCEDURE: Cows were examined at the time of initial identification of disease (time 0) and classified as having mild, moderate, or severe disease on the basis of rectal temperature, hydration status, rumen contraction rate, and attitude. A CBC and serum biochemical analyses were performed, and milk samples were submitted for bacterial culture at time 0 and 48 hours later. RESULTS: 69 cows were classified as having mild disease, 44 as having moderate disease, and 31 as having severe disease. Median WBC and neutrophil counts were significantly lower in cows with moderate or severe disease at time 0 than in cows with mild disease. Band neutrophil count was significantly higher at 48 hours and serum calcium concentration was significantly lower at time 0 and at 48 hours in cows with severe or moderate disease, compared with cows with mild disease. Twenty-eight, 51, and 77% of cows with mild, moderate, and severe disease, respectively, had > 100,000 colony-forming units/ml of milk at time 0. The odds that a cow with severe disease would die or be culled were 3.6 times the odds for a cow with moderate disease and 11.2 times the odds for a cow with mild disease. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that a classification scheme based on readily observable systemic disease signs can be used to classify disease severity in cows with acute coliform mastitis.  相似文献   
34.
Postpartum and lactating crossbred cows containing a percentage of Bos indicus breeding at three locations were studied to determine the efficacy of GnRH + PGF2alpha combinations for synchronization of estrus and(or) ovulation. Cows were equally distributed to each of three treatments by body condition score at the start of the experiment (d 0). All cows received 100 microg of GnRH on d 0 and 25 mg of PGF2alpha 7 d later. The three insemination protocols included 1) AI 12 h after exhibiting estrus during d 7 to 12 of the experiment (Select-Synch; n = 197); 2) timed-AI + 100 microg of GnRH on d 9 of the experiment (CO-Synch; n = 193); 3) AI 12 h after exhibiting estrus during d 7 to 10 of the experiment. Cows not exhibiting estrus by d 10 were timed-AI and injected with 100 microg of GnRH on d 10 of the experiment (Hybrid-Synch; n = 200). The percentage of cows exhibiting estrus during d 7 to 12 of the experiment was lower (P < 0.05) for CO-Synch (17.6%) cows than for Select-Synch or Hybrid-Synch (45.2 and 33.0%, respectively) cows, which did not differ (P > 0.05). For the Select-Synch and Hybrid-Synch cows that exhibited estrus during d 7 to 10 of the experiment and were artificially inseminated, conception rates were similar across treatments (50.5%). Pregnancy rates were greater (P < 0.01) for CO-Synch and Hybrid-Synch (31.0 and 35.5%, respectively) cows than for Select-Synch (20.8%) cows. A greater (P < 0.01) percentage of cycling cows became pregnant (34.5%) than noncycling cows (25.9%) across all treatments. The CO-Synch and Hybrid-Synch synchronization protocols resulted in greater pregnancy rates compared with the Select-Synch protocol in postpartum and lactating crossbred cows containing a percentage of Bos indicus breeding.  相似文献   
35.
OBJECTIVE: To document uterine growth and microvascular development in the endometrium of uteri with differing degrees of fibrosis as well as uterine growth throughout the estrous cycle of mares. ANIMALS: 30 mares. PROCEDURE: Uterine tissue was obtained during the breeding season from a slaughter facility. Stage of estrous cycle of the mares was assessed on the basis of ovarian structures and plasma progesterone concentrations. Endometrium was characterized by use of light microscopy, and blood vessel walls were marked by histochemical techniques. Microvascular development was evaluated by a computerized image analysis system. Growth of uterine tissue was based on cellular content of DNA and RNA, RNA:DNA, and protein:DNA. RESULTS: Significant differences in vascular density were not observed in the endometrium of uteri obtained from mares euthanatized during the follicular or luteal phase of the estrous cycle, regardless of whether endometrial classification of degree of fibrosis was considered. There was a 3-fold increase in amount of DNA and RNA of endometrial cells in the follicular phase when compared to myometrium. Hypertrophy of endometrial tissue during the luteal phase was reflected by a significant increase in cell protein content and protein:DNA. CONCLUSIONS AND CLINICAL RELEVANCE: Endometrial growth of vascular tissues during the estrous cycle may be coordinated with development of nonvascular tissue. Estrogen and progesterone may play a role in regulation of uterine growth and angiogenesis.  相似文献   
36.
Atopic dermatitis is a well-recognised chronic inflammatory skin disease of humans and dogs. Most atopic dogs are sensitised to Dermatophagoides mites. The aim of this study was to characterise allergens in different Dermatophagoides species using polyclonal and monoclonal antibodies to canine IgE. Western blots were prepared from crude extracts of D farinae, D pteronyssinus and D microceras, and purified group 1 and 2 allergens under reducing and non-reducing conditions. They were probed with sera from atopic (n = 33) and healthy (n = 27) dogs. There was no significant difference in the sensitivity or specificity between the polyclonal and monoclonal sera in detecting Dermatophagoides -specific IgE. Major allergens common to both D farinae and D pteronyssinus were detected at 97-98 kDa, 103-104 kDa and 134-139 kDa on both reducing and non-reducing blots. Major allergens at 84-85 kDa, 65-69 kDa and 44-45 kDa were only recognised on reducing blots, suggesting that these are fragments of the larger allergens. Only a few sera recognised group 1 or 2 allergens on blots of crude extracts or purified allergens. These results confirm that, in atopic dogs, high molecular weight allergens are the most important Dermatophagoides allergens, rather than the low molecular weight group 1 and 2 proteins.  相似文献   
37.
Cytokine gene expression in ileal tissues of cattle infected with Mycobacterium paratuberculosis was evaluated. The effects of infection with M. paratuberculosis on cytokine production may influence immune regulation at the site of colonization, resulting in the chronic inflammatory state associated with the latter stages of this disease. Ileal samples were obtained at necropsy from noninfected control cows (n=8) and clinically infected cows (n=7) and processed for immunohistochemistry and in situ hybridization. Cows infected with M. paratuberculosis were in the latter stages of disease with clinical signs such as weight loss, watery diarrhea, and inappetence. Among cytokines we studied, interleukin-1alpha (IL-1alpha), IL-1beta, IL-6, and interferon-gamma (IFN-gamma) were expressed significantly more in infected animals than in noninfected control animals. The expression of tumor necrosis factor-alpha (TNF-alpha), however, was not different between the two groups of cattle. In addition, immunohistochemical staining demonstrated that the number of resident macrophages in the ileum of infected animals was three times greater than that of noninfected cows. In contrast to this, ileal tissues from noninfected control animals contained 1.5 times more neutrophils than the ileal tissues from cows infected with M. paratuberculosis. These data demonstrate that localized ileal cytokine production is different between cows chronically infected with M. paratuberculosis and noninfected control cows.  相似文献   
38.
The objective was to test the hypothesis that dopamine regulates prolactin (PRL) secretion by determining acute changes in catecholamine concentrations in hypophyseal portal blood of cattle, and their relation to peripheral blood concentration of PRL in hypophyseal stalk-transected (HST) and sham-operated controls (SOC). Holstein heifers (606 +/- 21 kg BW; mean +/- SE) were subjected to neurosurgery for 8 h to collect hypophyseal portal blood with a stainless steel cannula designed with a cuff placed under the pituitary stalk and peripheral blood via a jugular vein catheter. PRL plasma concentration was measured by radioimmunoassay, and dopamine and norepinephrine in portal plasma by radioenzymatic assay. During anesthesia before HST or SOC, PRL plasma concentration ranged from 20-40 ng/ml throughout 255 min. PRL abruptly increased and remained above 90 ng/ml after HST compared with a steady decrease to <20 ng/ml in SOC heifers throughout 440 min. Within 5 min after severing the hypophyseal stalk, dopamine in portal blood (>8 ng/ml) was significantly increased (P < 0.05) compared with peripheral blood (<2 ng/ml). Norepinephrine concentration in portal blood was significantly greater (P < 0.05) than in peripheral blood during the first 60 min. The sustained high PRL level in peripheral plasma after severing the hypophyseal stalk stimulated hypothalamic dopamine secretion from hypophyseal portal vessels during the prolonged period of blood collection. Norepinephrine concentration in these cattle was greater in hypophyseal portal than in peripheral blood, implicating both an important hypothalamic source of the catecholamine as well as an adrenal gland contribution during anesthesia.  相似文献   
39.
The purpose of this study was to evaluate the surgical outcomes of 28 dogs with generalized septic peritonitis treated without postoperative abdominal drainage. The overall mortality rate was 46%, with most cases of peritonitis being caused by leakage of the gastrointestinal tract (75%). Etiology of peritonitis, abdominal cytopathology, total white blood cell count, packed cell volume, total protein, and results of serum biochemistries were not statistically different between survivors and nonsurvivors. The mortality rate of 46% is similar to other studies in which the abdomen was left open postoperatively for the management of septic peritonitis, although more advanced medical treatment than that used in earlier studies may have positively affected the outcome. The results of this study show that closure of the abdomen after the source of contamination has been successfully corrected, in combination with thorough intraoperative peritoneal lavage and appropriate postoperative medical management, may be an acceptable alternative method for the management of septic peritonitis.  相似文献   
40.
The purpose of this report was to evaluate the clinical safety and efficacy of sevoflurane as an inhalant anesthetic in dogs. Subjective and objective data from 196 clinical cases utilizing sevoflurane as the maintenance anesthetic was collected at three sites. After preanesthetic evaluation, the attending anesthesiologist assigned the dogs to one of the following six anesthetic protocols: protocol 1, oxymorphone premedication and thiopental induction; protocol 2, oxymorphone/acetylpromazine premedication and thiopental induction; protocol 3, xylazine/butorphanol premedication and thiopental induction; protocol 4, opioid premedication and propofol induction; protocol 5, optional premedication and mask induction with sevoflurane in oxygen; and protocol 6, optional premedication and optional induction. The average quality of induction, maintenance, and recovery was good to excellent in all protocols. The three most common side effects during maintenance and recovery were hypotension, tachypnea, and apnea. Sevoflurane produces anesthesia in dogs comparable to the other inhalation anesthetics currently used (i.e., halothane and isoflurane) for diagnostic or therapeutic procedures.  相似文献   
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