The Standardization of an Apparatus for the Mixing of Soil Samples for Nematode Extractions

Quantitative determination of nematode populations in soils frequently necessitates the mixing of representative soil samples to form a homogeneous, compound sample from which the nematodes are extracted. A mixing apparatus was developed and standardized with the aid of a spectrophotometric technique by which the dispersion of a dye through the soil during mixing could be determined. It was found that the mixer is most suitable for use on sandy loam soils. Optimal mixing is obtained at a speed of 15 rpm for 2 minutes. Under these conditions mechanical damage to nematodes during mixing is minimal.     

猪精子质量的流式细胞检测分析

本试验将流式细胞术应用于猪精子分析,同时检测精子功能的多个特性,以保证精子具备多种特性且功能完整,顺利完成授精过程。分别采用SYBR-14/PI（Propidium Iodide）、YO-PRO-1/PI、PNA/PI及Mito Tracker/YO-PRO-1 4种染色方法对荣昌猪精子的质膜完整性、细胞凋亡、顶体完整性及线粒体功能进行了检测和分析;以SYBR-14⁺/PI^-表示质膜完整的活精子,YO-PRO-1^-/PI^-表示活精子,PNA^-/PI^-表示未发生顶体反应的活精子,Mito Tracker⁺/YO-PRO-1^-表示线粒体活性高的活精子,以上述检测指标的综合结果判定精子功能的完整性。本试验通过流式细胞术对荣昌猪精子进行质量检测和分析,结果表明,该方法可为临床诊断种猪不孕症提供理论依据,对有效治疗不孕症有重要意义。     

Flow cytometric evaluation of ki67 for the determination of malignancy grade in canine lymphoma

Ki67 is a nuclear antigen significantly correlated with degree of malignancy in human non‐Hodgkin lymphomas. We wanted to assess the ability of flow cytometric evaluation of Ki67 index (Ki67I) in differentiating the grade of malignancy in canine lymphomas. Ki67I was determined on lymph node aspirates of 90 immunophenotyped lymphomas classified according to the updated Kiel classification: 80 high grade (HG, 62 B cell and 18 T cell) and 10 low grade (LG, 3 B cell and 7 T cell) lymphomas. HG lymphomas showed significantly higher Ki67I compared with LG lymphomas (P < 0.0001). A significant difference in HG lymphomas was detected between B‐ and T‐immunophenotypes. Receiver operating characteristic (ROC) curve highlighted a high accuracy of Ki67I in recognizing HG lymphomas [area under the curve (AUC) = 99.4] and a cut‐off value of 12.2% was established (sensitivity = 96.3% and specificity = 100%). Thus, we suggest the combination of Ki67I flow cytometric determination and immunophenotype as a reliable tool to classify canine lymphomas.     

Feed processing and structural components affect starch digestion dynamics in broiler chickens

1. A 2 × 2 factorial design was used to test the hypothesis that impaired intestinal starch digestibility is attributable to rapid passage of digesta from the gizzard to the intestine, and that, compared to steam pelleting, increasing the availability of starch through extrusion cooking may alleviate the potential negative effect of rapid digesta flow on starch utilisation.

2. Thus, 7-d-old-broiler chickens were distributed to 48 cages and given a wheat-based (WB) pelleted diet containing either coarse oat hulls (OH-Pel) or fine cellulose (Cel-Pel) until d 19 to stimulate divergent development of the gizzard. Thereafter, both groups were further subdivided and challenged with a WB diet containing cellulose in either pelleted (Cel-Pel) or extruded (Cel-Ext) form on d 20 and 22. Either excreta or intestinal contents were collected at time intervals after feeding and analysed for marker and starch.

3. OH-Pel increased gizzard size and holding capacity. No excessively high starch levels (maximum 25 g/kg) were detected in the excreta. However, 8 h feed-deprived birds given Cel-Pel and challenged with Cel-Pel exhibited higher starch excretion and showed large individual variation during the first 135 min of collection.

4. Contrary to the OH-Pel group, more digesta and starch passed to the jejunum at 1 and 2 h and ileum at 2 and 3 h after feeding for birds given Cel-Pel, resulting in lower jejunal and ileal starch digestibility.

5. Increased starch gelatinisation through extrusion processing significantly improved starch digestibility regardless of gizzard function. However, at 1, 2 and 3 h after feeding, more digesta was retained in the foregut of birds given Cel-Ext.

6. The current data showed that starch degradation rate is associated with the flow of digesta which is linked to gizzard development, and that enzymatic hydrolysis of intact starch granules may be limited with more rapid feed passage through the gut.     

The social construction of production externalities in contemporary agriculture: Process <Emphasis Type="Italic">versus</Emphasis> product standards as the basis for defining “organic”

The analysis distinguishes two types of standards for defining organic produce; process standards and product standards. Process standards define organic products by the method and means of production. Product standards define organic by the physical quality of the end product. The National Organic Program (NOP) uses process standards as the basis for defining organic. However, the situation is complicated by agricultural production practices, which sometimes result in the migration of NOP prohibited substances from conventional to organic fields. When this interaction alters the value of the product or the costs of production, a production externality is said to exist. Defining organic using process, rather than product standards, influences the burden and character of production externalities. The NOPs emphasis on process standards reduces the likelihood that production externalities will emerge.B. James Deaton is an Assistant Professor in the Department of Business and Agricultural Economics, University of Guelph, Canada. His research examines environmental and natural resource issues. He is particularly interested in the manner in which laws, rules, and standards influence environmental quality, natural resource use, and economic development. Additional research examines the relationship between different forms of private property and economic development, public support for various criteria used to preserve farmland, and the social construction of production externalities in agriculture. Prior to his PhD training, he worked on economic development projects in Lesotho (Southern Africa) and the Appalachian region of eastern Kentucky.John P. Hoehn is a Professor of Environmental and Natural Resource Economics in the Department of Agricultural Economics, Michigan State University. His teaching and research activities address environmental and natural resource policies, benefit-cost analysis of environmental improvements, methods for valuing non-market goods, improved institutions for protecting, managing, and using environmental resources, and the economics of ecological resources. He teaches core courses in the departmental and university-wide graduate programs in environmental and resource economics.     

EFFECTS OF ACEPROMAZINE ON THREE-PHASE 99mTc-MDP BONE IMAGING IN 11 HORSES

Horses undergoing skeletal scintigraphy can have decreased radiopharmaceutical bone uptake in the limbs. This reduces the diagnostic value of the scan. The aim of the present study was to measure the changes in count density caused by vasodilatation and increased blood flow associated with intravenous injection of acepromazine during bone scintigraphy in normal horses. A three-phase bone scan was performed twice in 11 adult horses to study the effects of acepromazine on the count density of the resultant scintigrams. With acepromazine, there was a statistically significant mean difference of 12 s for initial blood flow and 21 s for peak flow. The time to initial blood flow and time to peak flow occurred earlier for the scans in which acepromazine was used. There were no significant differences in the bone to soft tissue ratios during the soft tissue and bone phases of the scan between procedures. Intravenous administration of acepromazine increases peripheral blood flow causing an earlier onset of the vascular phase during the three-phase bone scan. Acepromazine did not increase the count density of the bone phase scintigrams. As expected, the vasodilatation and increased blood flow associated with intravenous injection of acepromazine affected the count density of the vascular phase of the bone scan.     

Birth of puppies of predetermined sex after artificial insemination with a low number of sex‐sorted,frozen–thawed spermatozoa in field conditions

The aim of this study was to evaluate fertility and sex ratios after artificial insemination in dogs under field conditions. Semen was cryopreserved as unsorted (control) or was separated into X‐ and Y‐chromosome‐bearing sperm using a cell sorter. Sixty female dogs were inseminated with frozen–thawed spermatozoa of 100 × 10⁶ unsorted (a dose in practice) and 4 × 10⁶ sorted (X and Y group, respectively). A total of 20 dogs became pregnant and 126 puppies were born from the three groups. The percentage of parturition was similar for the X (5/20; 25.0%) and Y (4/20; 20.0%) group (P > 0.05), but lower than controls (11/20; 55.0%) (P < 0.05). Ultimately 28 out of the 32 puppies produced from X group were female (87.5%) and 19/22 (86.4%) puppies of Y group were male. In contrast, sex ratio (51.4% to 48.6%) in the control was significantly different from the X, Y group (P < 0.05). However, male and female puppies in the control had similar birth weights and weaning weights to those from the X and Y groups. This preliminary information indicated that normal puppies of predicted sex can be produced with low numbers of sorted cryopreserved dog spermatozoa at a farm level, making sperm‐sexing technology potentially applicable for elite breeding units.     

Bilirubin excretion and bile flow in fed and fasted Brazilian squirrel monkeys (Saimiri sciureus)

Fasted Brazilian squirrel monkeys (BrSMs) exhibited slightly higher serum bilirubin levels (0.30±0.05 mg/dl) than others in the fed state (0.13±0.01). The mean liver weight was 50% lower following a 22 h fast. The rate of bile flow was unaffected by fasting and averaged 13.8 l/min/kg and 47.5 l/min/100g liver in six BrSMs. No significant difference in mean bilirubin excretion/min was observed on a body weight basis following fasting. When the mean rate of bilirubin excretion was calculated as a function of liver weight, a two-fold higher rate was present in fasted monkeys, but only at the p=0.06 level of statistical significance. From data collected in this and earlier studies, it would appear that BrSMs represent the best animals studied to date to serve as experimental controls in comparative studies with Bovilian squirrel monkeys which exhibit a Gilbert-like syndrome.