栽培食用菌补充营养的技巧

1．补养方法给食用菌补允营养的方法有喷洒、灌注和浸泡。最常用的方法是配制一定浓度的营养液，在菌床、菌块上喷洒。在幼苗期喷洒时，要注意将营养喷在无菇处或小菇蕾附近，     

Effects of pasteurization of colostrum on subsequent serum lactoferrin concentration and neutrophil superoxide production in calves

OBJECTIVE: To determine the effects of pasteurization of colostrum on serum lactoferrin concentration and neutrophil oxidative function by comparing values from calves given pasteurized (76 C, 15 minutes) colostrum versus calves given fresh frozen colostrum. ANIMALS: 8 Holstein bull calves were used to study the effects of pasteurization of colostrum on the absorption of lactoferrin and neutrophil oxidative burst. Three additional calves were used to study the effect of exogenous lactoferrin on neutrophil oxidative burst. METHODS: Calves were fed fresh frozen or heat pasteurized colostrum (76 C for 15 minutes) via esophageal feeder within 4 hours of birth. Neutrophils were isolated from whole blood samples. Neutrophil oxidative burst was induced by phorbol ester (300 ng/ml) stimulation of cells (1 X 10(6) cells) at 37 C. Serum lactoferrin concentrations were compared, using immunoblot analysis. Serum IgG concentrations were determined by radial immunoassay. Comparisons were made between the use of the 2 types of colostrum in calves by measuring subsequent serum IgG and lactoferrin concentrations and neutrophil superoxide production. RESULTS: Serum IgG and lactoferrin concentrations increased more in calves receiving fresh frozen colostrum. Neutrophil superoxide production was higher in neutrophils prepared from calves receiving fresh frozen colostrum. Colostral lactoferrin addition to neutrophil incubations resulted in increased oxidative burst. CONCLUSIONS AND CLINICAL RELEVANCE: Compared with calves given fresh frozen colostrum, calves given pasteurized colostrum had decreased serum IgG and lactoferrin concentrations and neutrophil superoxide production 24 hours after administration. These results suggest that pasteurizing bovine colostrum at 76 C for 15 minutes has substantial effects on passive transfer of proteins and neutrophil function.     

Technical note: recombinant LHRH fusion protein suppresses estrus in heifers

A recombinant luteinizing hormone-releasing hormone (LHRH) fusion protein was evaluated for its effectiveness in suppression of estrus in heifers. Eight heifers were randomly assigned to two equal treatment groups. Treatments consisted of recombinant ovalbumin-LHRH-7 or recombinant ovalbumin (control). This recombinant chimeric fusion protein consisted of ovalbumin with seven LHRH peptides (ovalbumin-LHRH-7). The plasmid for this protein was expressed in E. coli and was collected and purified as an insoluble protein. One milligram of the respective proteins was suspended in 2 mL of Z-Max adjuvant and administered by intramammary injection three times at 7-wk intervals. Luteinizing hormone-releasing hormone antibody binding was elevated in heifers treated with ovalbumin-LHRH-7 compared to ovalbumin-treated heifers (P < .05). Serum progesterone concentrations (< 1 ng/mL) indicate that the estrous cycle of the four heifers treated with ovalbumin-LHRH-7 was suppressed for a time period ranging from 60 to 238 d, which was different from control heifers (P < .01). Serum progesterone for the control heifers continued to exhibit cyclic profiles over the experimental period. This preliminary study in heifers demonstrated that a chimeric LHRH fusion protein induced elevated concentrations of circulating LHRH antibodies that suppressed estrus for an average of 122 +/- 41 d.     

Synovial fluid analysis in cattle: a review of 130 cases

OBJECTIVE: To compare synovial fluid characteristics of cattle with infectious and noninfectious arthritis. STUDY DESIGN: Retrospective cohort study. ANIMAL OR SAMPLE POPULATION: 130 cattle. METHODS: Synovial fluid was analyzed for total nucleated cell count (NCC), absolute number and percentages of polymorphonuclear (PMN) and mononuclear cells, total protein (TP) concentration, and specific gravity. Cattle were categorized as having infectious or noninfectious arthritis based on physical and lameness examinations, joint radiographs, and microbial culture results. Kruskal-Wallis 1-way analysis of variance was used to compare synovial fluid analysis data from different categories. Selection of cut-off values for the calculation of likelihood ratios, sensitivity, specificity, and positive and negative predictive values was based on examination of the distribution of the data using histograms. RESULTS: Cattle with infectious arthritis had significantly higher numbers of total NNC, PMN cells, TP concentration, and specific gravity (P = .0001) and a significantly higher percentage of PMN cells compared with cattle with noninfectious arthritis (P = .0001). The percentage of mononuclear cells was significantly higher in cattle with noninfectious arthritis (P = .0001). CONCLUSIONS: Synovial fluid analysis is useful for differentiation of infectious and noninfectious causes of joint disease in cattle. CLINICAL RELEVANCE: Cattle with a synovial fluid total NCC > 25,000 cells/microL, a PMN cell count > 20,000 cells/microL or more than 80% PMN cells, and TP > 4.5 g/dL should be considered to have infectious arthritis.     

用乳清补饲牦(犏)牛犊效果分析

实验目的: 乳清为鲜奶脱脂脱酪后的残液,其中所含氨基酸、乳清蛋白和PH值根据氨基酸分析仪及美国AACC方法测得的结果见表1: 表1 牦牛乳清氨基酸、乳清蛋白含量及PH值     

Academic food-supply veterinarians: future demand and likely shortages

The future demand for and potential shortages of food-supply veterinarians have been the subject of much concern. Using the Delphi forecasting method in a three-phase Web-based survey process, a panel of experts identified the trends and issues shaping the demand for and supply of academic food-animal veterinarians, then forecasted the likely future demand and shortages of food-supply veterinarians employed in academic institutions in the United States and Canada through 2016. The results indicate that there will be increasing future demand and persistent shortages of academic food-supply veterinarians unless current trends are countered with targeted, strategic action. The Delphi panel also evaluated the effectiveness of several strategies for reversing current trends and increasing the number of food-supply veterinarians entering into academic careers. Academic food-supply veterinarians are a key link in the system that produces food-supply veterinarians for all sectors (private practice, government service, etc.); shortages in the academic sector will amplify shortages wherever food-supply veterinarians are needed. Even fairly small shortages have significant public-health, food-safety, animal-welfare, and bio-security implications. Recent events demonstrate that in an increasingly interconnected global economic food supply system, national economies and public health are at risk unless an adequate supply of appropriately trained food-supply veterinarians is available to counter a wide variety of threats ranging from animal and zoonotic diseases to bioterrorism.     

Idiopathic primary chylopericardium in a dog

CASE DESCRIPTION: A 7-year-old spayed female Labrador Retriever was evaluated because of pericardial effusion. CLINICAL FINDINGS: The dog had a history of decreased appetite and exercise intolerance of 3 days' duration. Thoracic radiography performed by the referring veterinarian revealed a large cardiac silhouette. Heart sounds were muffled. Echocardiographic findings were indicative of severe pericardial effusion with cardiac tamponade; no pleural effusion was identified. Pericardiocentesis yielded a considerable amount of chylous fluid. A diagnosis of chylopericardium in the absence of pleural effusion was made. TREATMENT AND OUTCOME: Conservative management was not effective, and subtotal pericardectomy and thoracic duct ligation were recommended. Surgery was postponed by the owners for 25 days, at which time the dog had both chylopericardium and chylothorax. The dog underwent subtotal pericardectomy and thoracic duct ligation; to delineate the thoracic duct, intraoperative lymphangiography was performed by injection of a radiopaque contrast agent directly into a mesenteric lymph node and subsequent injection of methylene blue solution into another mesenteric lymph node. Surgical treatment resulted in complete resolution of the clinical signs and pleural effusion. CLINICAL RELEVANCE: To the authors' knowledge, this is the first report of the development of chylopericardium prior to development of chylothorax in a dog. Treatment with thoracic duct ligation and pericardectomy resulted in complete resolution of the effusion and clinical signs.     

Pharmacokinetics of buprenorphine following intravenous administration in dogs

OBJECTIVE: To determine pharmacokinetics of buprenorphine in dogs after i.v. administration. ANIMALS: 6 healthy adult dogs. PROCEDURES: 6 dogs received buprenorphine at 0.015 mg/kg, i.v. Blood samples were collected at time 0 prior to drug administration and at 2, 5, 10, 15, 20, 30, 40, 60, 90, 120, 180, 240, 360, 540, 720, 1,080, and 1,440 minutes after drug administration. Serum buprenorphine concentrations were determined by use of double-antibody radioimmunoassay. Data were subjected to noncompartmental analysis with area under the time-concentration curve to infinity (AUC) and area under the first moment curve calculated to infinity by use of a log-linear trapezoidal model. Other kinetic variables included terminal rate constant (k(el)) and elimination half-life (t(1/2)), plasma clearance (Cl), volume of distribution at steady state (Vd(ss)), and mean residence time (MRT). Time to maximal concentration (T(max)) and maximal serum concentration (C(max)) were measured. RESULTS: Median (range) values for T(max) and MRT were 2 minutes (2 to 5 minutes) and 264 minutes (199 to 600 minutes), respectively. Harmonic mean and pseudo SD for t(1/2) were 270+/-130 minutes; mean +/- SD values for remaining pharmacokinetic variables were as follows: C(max), 14+/-2.6 ng/mL; AUC, 3,082+/-1,047 ng x min/mL; Vd(ss), 1.59+/-0.285 L/kg; Cl, 5.4+/-1.9 mL/min/kg; and, k(el), 0.0026+/-0.0,012. CONCLUSIONS AND CLINICAL RELEVANCE: Pharmacokinetic variables of buprenorphine reported here differed from those previously reported for dogs. Wide variations in individual t(1/2) values suggested that dosing intervals be based on assessment of pain status rather than prescribed dosing intervals.     

Applicant expectations and decision factors for jobs and careers in food-supply veterinary medicine

This article examines the job expectations of applicants as reported by recruiters interviewing food-supply veterinary medicine (FSVM) candidates and the career-choice decision factors used by year 3 and 4 veterinary students pursuing careers in FSVM. The responses of 1,047 veterinary recruiters and 270 year 3 and 4 students with a food-supply focus from 32 colleges of veterinary medicine in the United States and Canada were examined. Recruiters were asked to report the two most important job factors applicants took into account when deciding to accept an offer; students were asked the two most important reasons for choosing a career in FSVM and the two most important benefits of working as a food-supply veterinarian. Recruiters reported that high salaries and good benefits are the two most important decision factors. Interest in the food-animal career area and a desire for a rural, outdoor lifestyle were the top reasons students gave for choosing an FSVM career. Students saw the enjoyment of working with and helping producers and food animals as the most important benefits of a career in FSVM.