The use of hand-held terminals and micro-computers for the recording and analysis of potato cyst nematode counts     

Linda Farrer  C. M. NG Stephen 《Euphytica》1982,31(2):507-510

Summary An automated system of data capture and summarisation is described. Although it is of widespread applicability, it is illustrated by a specific example involving the screening of potato tubers for resistance to potato cyst nematode.  相似文献   

Implications of intensification of pastoral animal production on animal welfare     

KJ Stafford  NG Gregory 《New Zealand veterinary journal》2013,61(6):274-280

The intensification of pastoral animal production results from several major developments including increased forage production and utilisation, diet supplementation, breeding animals to increase milk, meat or wool production, and changes in management. The impact of increased intensification on welfare will differ across species and systems. More intensive-grazing systems and the feeding of novel forages will underpin all moves to intensification. More intensive grazing generally reduces opportunities for shade and shelter. Improved nutrition will generally benefit welfare but competition for available feed may cause increased social pressure. Increased flock and herd size will be associated with a reduction in the human:animal ratio and less time to observe individual animals. Remote monitoring of activity and health might counter this impact.

Intensification of dairy production will result in larger herds, more year-round milking, robotic milking, use of housing and yards year round, and total mixed-ration feeding. Larger herds mean longer distances to walk to and from the dairy shed, and more lameness and less time to spend on self-maintenance activities such as grooming. Holding and feeding dairy cows on yards will cause an increase in lameness and mastitis and perhaps an increase in agonistic behaviour but will reduce time spent walking. Intensification of sheep production will involve increased flock size, increased fecundity, breeding from hoggets, and breeding ewes all year round. Housing during lambing might be considered appropriate, as would feeding to lift milk yields. Increased fecundity with an increase in triplets will increase lamb mortality rates, but housing ewes, when managed well, will result in reduced lamb mortality. Intensification of lamb finishing will be by improved nutrition. Intensification of beef production will include more breeding of heifers at 15 months, and more problems with dystocia.

Intensification of pastoral production will have positive and negative effects on animal welfare. The balance will be determined by the quality of management and stockmanship, and the pressure on businesses to be profitable.  相似文献   

鸡新城疫病毒HN基因亚单位疫苗诱导免疫保护的实验研究   总被引：3，自引：0，他引：3  

丁壮  金宁一  王兴龙  米志强  夏志平  王承宇 《动物医学进展》2002,23(1):49-51

实验分别将应用Bac to Bac系统表达的新城疫病毒四平株和长春株血凝素-神经氨酸酶基因（HN基因）蛋白的重组杆状病毒感染Sf-9昆虫细胞后28℃培养72h后，洗涤、收集昆虫细胞，离心浓缩，-20℃冻融3次，用HA-HI实验和HN单抗中和试验测定表达产物的活性，将表达的重组蛋白作为亚单位疫苗免疫鸡，用间接ELISA和HI试验测定鸡体内抗体效价，免疫后第15d用国家标准强毒NDVF48E8攻毒，统计免疫保护率，结果表明，表达的NDVHN重组蛋白能够诱导鸡体产生抗NDV特异性IgG抗体和HI抗体，实验Ⅰ组（四平株）雏鸡保护率为65%，实验Ⅱ组（长春株）雏鸡保护率为100%。  相似文献   

Book reviews     

Douglas P. Ormrod  NG Wun Jern  T. Viraraghavan 《Water, air, and soil pollution》1993,69(3-4):443-448

  相似文献   

The elimination of injected superoxide dismutase from synovial fluid of the horse     

DE AUER  JC NG  J. HRDLICKA  AA SEAWRIGHT 《Australian veterinary journal》1989,66(4):117-119

  相似文献   

Assessment of copper and zinc status of farm horses and training thoroughbreds in south-east Queensland   总被引：2，自引：0，他引：2  

DE AUER  JC NG  AA SEAWRIGHT 《Australian veterinary journal》1988,65(10):317-320

The copper and zinc concentrations in the blood of stabled thoroughbred horses and in Australian Stock Horses mares at pasture, either late pregnant or lactating were determined by an atomic absorption spectroscopic method. The plasma concentration of the trace elements in these apparently normal horses were generally below the "normal" range. The plasma copper, caeruloplasmin copper, whole blood copper and plasma zinc concentrations in the stabled thoroughbreds were 0.76 +/- 0.19 micrograms/ml (n = 82), 0.56 +/- 0.14 micrograms/ml (n = 83), 0.75 +/- 0.18 micrograms/ml (n = 82) and 0.47 +/- 0.09 micrograms/ml (n = 83) respectively. The plasma copper and zinc concentrations of all the brood mares at pasture (pregnant and lactating) were 0.56 +/- 0.20 micrograms/ml and 0.47 +/- 0.11 micrograms/ml (n = 30). The plasma copper concentration of the pregnant group of mares (0.64 +/- 0.18 micrograms/ml; (n = 14) was greater than that of the lactating mares (0.49 +/- 0.21; (n = 16). Variation in the plasma copper concentration was also identified between stabled and farm horses, between horses of different stables and between horses of different ages. The proportion of plasma copper bound to caeruloplasmin was 73 +/- 11.8%. These low concentrations of copper and zinc in the plasma of apparently normal horses are of clinical significance since recent evidence has indicated that copper deficiency appears to promote the development of skeletal abnormalities in foals. An alternative to the use of a single plasma sample to identify the copper or zinc deficient horse was discussed.  相似文献   

Palm oil-laden spent bleaching clay as a substitute for marine fish oil in the diets of Nile tilapia, Oreochromis niloticus     

W.-K. NG  C.-B. KOH  & Z.B. DIN 《Aquaculture Nutrition》2006,12(6):459-468

A 8‐week feeding trial was conducted to determine the effect of substituting fish oil with palm oil‐laden spent bleaching clay (SBC), a by‐product from crude palm oil (CPO) refining, on growth, feed utilization, fatty acid composition and heavy metal accumulation in the muscle of Nile tilapia, Oreochromis niloticus. Four isonitrogenous and isolipidic practical diets were formulated to contain 0, 100, 200 or 300 g kg^?1 SBC. Growth performance of Nile tilapia was significantly better in fish fed the 100 g kg^?1 SBC diet compared with fish fed the 0, 200 or 300 g kg^?1 SBC diet. Growth and feed utilization efficiency of fish fed 200 or 300 g kg^?1 SBC were similar to fish fed the control diet without added SBC. Whole‐body composition, body‐organ indices and haematocrit of tilapia were not affected by dietary treatments. Fatty acid compositions in the muscle lipid of Nile tilapia were strongly influenced by dietary treatments with progressively elevated levels of total saturates and n‐6 PUFA because of the dietary influence of these fatty acids from residual CPO adsorbed onto SBC. A gradual decrease in total n‐3 PUFA concentrations were also observed with the ratio of n‐3 to n‐6 fatty acids in muscle lipids decreasing from 4.75 to 4.41, 3.23 or 2.37 after 8 weeks on the 0, 100, 200 or 300 g kg^?1 SBC diet, respectively. The arsenic, cadmium and lead concentrations in the experimental diets increased with increasing dietary levels of SBC but the concentrations of these heavy metals in the whole body and bone of Nile tilapia were not significantly different among fish fed the various diets. The present 8‐week study showed that in fishmeal‐based diets for Nile tilapia, palm oil‐laden SBC can totally replace added fish oil. The use of this presently discarded waste product from palm oil refining in tilapia diets will greatly contribute to reducing the impact of rising feed costs in the culture of tilapia in many tropical countries. Other potential benefits may include acting as a feed binder, removal of mycotoxins in fish feeds as well as adsorbing toxic substances present in the culture water.  相似文献   

Single-Electron Transport in Ropes of Carbon Nanotubes     

M Bockrath  DH Cobden  PL McEuen  NG Chopra  A Zettl  A Thess  RE Smalley 《Science (New York, N.Y.)》1997,275(5308):1922-1925

The electrical properties of individual bundles, or "ropes," of single-walled carbon nanotubes have been measured. Below about 10 kelvin, the low-bias conductance was suppressed for voltages less than a few millivolts. In addition, dramatic peaks were observed in the conductance as a function of a gate voltage that modulated the number of electrons in the rope. These results are interpreted in terms of single-electron charging and resonant tunneling through the quantized energy levels of the nanotubes composing the rope.  相似文献   

北京市城区近郊区生活垃圾成分调查及可农用性分析     

刘克锋  石爱平  王红利  刘悦秋  刘彩玲  邢汝明 《农业环境科学学报》2002,21(3):232-236

对北京市城区和近郊区的新鲜城市生活垃圾进行了分类调查和理化性质测定。结果表明:(1)新鲜生活垃圾可农用部分占84.04%,冬季可农用部分所占比率高;(2)垃圾肥料有机质含量在12.50%—19.70%范围,全氮在0.53%—0.87%范围;(3)垃圾肥料重金属含量和残毒含量符合国家卫生标准和城市垃圾农用控制标准。建议垃圾肥料与处理过的禽畜粪便混合,可生产出优质有机肥料。  相似文献   

Influence of soil physicochemical and biological properties on the degradation and adsorption of the nematicide fosthiazate   总被引：1，自引：0，他引：1  

Pantelelis I  Karpouzas DG  Menkissoglu-Spiroudi U  Tsiropoulos N 《Journal of agricultural and food chemistry》2006,54(18):6783-6789

The degradation and adsorption of the organophosphorus nematicide fosthiazate were investigated in nine soils with various physicochemical and biological characteristics. Fosthiazate was more persistent in acidic soils (pH <6), with half-life (t1/2) values ranging from 53.3 to 57.7 days, compared to soils with higher pH (pH >7), with t1/2 ranging from 14.1 to 20.7 days. Application of antibacterial and antifungal antibiotics to soil samples resulted in a significant inhibition of fosthiazate degradation only in two of the three acidic soils. In contrast, soil autoclaving resulted in doubling the t1/2 of fosthiazate in all studied soils, suggesting that both microbial and abiotic processes contribute to fosthiazate degradation. Statistical analysis indicated a significant negative correlation (P < 0.01) between soil pH and t1/2. Fosthiazate was generally weakly adsorbed with Freundlich adsorption coefficient (Kf) values ranging from 1.23 to 2.74 mL/g. Fosthiazate concentration was strongly correlated with soil organic matter content with higher Kf values in soils with higher organic matter content (P < 0.01). The mean t1/2 and Kf values derived from the laboratory studies were used to parametrize the FOCUS groundwater (GW) models PRZM, PELMO, PEARL, and MACRO for nematicide application in potato and tomato crops. Predicted environmental concentrations produced by the models PEARL and MACRO suggested a potential risk for GW in several scenarios, unlike PELMO and PRZM, which predicted low risk for GW. These findings suggest that the environmental fate of fosthiazate is strongly influenced by soil characteristics and that this nematicide should be used with care in acidic, light soils with low organic matter content.  相似文献