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91.
JR BUDDLE AR MERCY SZ SKIRROW F. MADEC RR NICHOLLS 《Australian veterinary journal》1997,75(4):274-281
Objective To determine in Australian pig herds the accuracy of French protocols for risk factor assessment.
Procedure Data on health indicators and risk factors were collected for three syndromes, 'pre-weaning diarrhoea', 'post-weaning diarrhoea' and 'respiratory problems', using the French protocols. The protocols were used on 118 occasions in 32 Western Australian pig herds during 3 years (1988 to 1991).
Results There was a wide variation in pre-weaning performance, for example growth rate was 107 to 273 g/day (< 200 g/day in 33% of herds). Respiratory lesions at weaning were associated with poor pre-weaning performance. Post-weaning (21 days after weaning) growth rate was 114 to 408 g/day (< 250 g/day in 54% of herds). In the grower herds, 91% of herds had pneumonia, and growth rate was 439 to 625 g/day (< 550 g/day in 54% of herds). Pleurisy as well as pneumonia was associated with reduced growth rate. The risk factor most closely associated with respiratory health status was air volume per pig.
Conclusion Risk factors were most accurate at predicting the health status in post-weaning problems. A weaning weight of at least 7.9 kg and weaning age of 30 days optimised weaner performance. Stocking densities and shed designs providing at least 3 m3 air volume and 0.6 m2 floor space per pig throughout the growing phase should be considered for an improved respiratory health status. Australian pig sheds often do not provide a satisfactory environment for optimum health. The technique of risk factor assessment as an aid to the maintenance of health in pig herds is applicable in Australia, but further research is necessary to determine the most important Australian risk factors. 相似文献
Procedure Data on health indicators and risk factors were collected for three syndromes, 'pre-weaning diarrhoea', 'post-weaning diarrhoea' and 'respiratory problems', using the French protocols. The protocols were used on 118 occasions in 32 Western Australian pig herds during 3 years (1988 to 1991).
Results There was a wide variation in pre-weaning performance, for example growth rate was 107 to 273 g/day (< 200 g/day in 33% of herds). Respiratory lesions at weaning were associated with poor pre-weaning performance. Post-weaning (21 days after weaning) growth rate was 114 to 408 g/day (< 250 g/day in 54% of herds). In the grower herds, 91% of herds had pneumonia, and growth rate was 439 to 625 g/day (< 550 g/day in 54% of herds). Pleurisy as well as pneumonia was associated with reduced growth rate. The risk factor most closely associated with respiratory health status was air volume per pig.
Conclusion Risk factors were most accurate at predicting the health status in post-weaning problems. A weaning weight of at least 7.9 kg and weaning age of 30 days optimised weaner performance. Stocking densities and shed designs providing at least 3 m
92.
摘要:针对大棚辣椒多年连续种植,导致大棚辣椒病虫害发生逐年加重、辣椒大幅减产、品质下降等问题,基于大棚辣椒主要病虫害发生特点及规律,通过试验和示范、推广,形成了1套以生态调控技术、生物防治技术、害虫诱杀技术和科学用药技术等为主要内容的全程绿色防控模式,并在生产中不断推广应用,病虫害防治效果达95%以上,化学农药使用量减少50%以上,农药残留合格率100%,提高了辣椒产量和品质,保证了农产品质量安全,生态效益显著;绿色防控区产投比(6.781)明显高于常规防控区(4.681),667 m2净收益较常规防控区高出4 111.0元,经济效益较好。 相似文献
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银杏为我国传统的名贵树种,其生长缓慢、结实晚,一般要20多a才能开花结实,并且产量低。阐述银杏的生物学特征、繁殖方式、栽培管理方法、修剪整形及病虫害防治等实用技术,旨在为扩大银杏园林生产、提高银杏的种植质量和产量提供有益的参考。 相似文献
95.
云南林木真菌病害研究(Ⅰ) 总被引:1,自引:1,他引:0
报道了云南林木真菌病害23种,其中:国内新记录4种,云南省内新记录11种,云南省内已知种新分布8种.前者有描述,其余以名录列后,拟供植保和植检工作参考. 相似文献
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Designing pest-suppressive multistrata perennial crop systems: shade-grown coffee in Central America
During most of its cultivation in Central America, coffee (Coffea arabica L.) suffered few serious pest problems. However, over the past three decades, three factors contributed to significantly
increase pest levels and losses: the recent introduction of new pests; more favorable conditions for existing pests, diseases,
and weeds due to lower shade levels; and secondary pest problems caused by pesticide use. The strategy of maximizing coffee
production with pest control dominated by synthetic pesticides has not only increased yields substantially, but also production
costs, pesticide resistance, and both human health and environmental risks. An analysis of the response of the food web in
coffee plantations to varying levels of light and humidity associated with different shade levels provides the basis for identifying
the optimum shade conditions which minimize the entire pest complex and maximize the effects of beneficial microflora and
fauna acting against it. These optimum shade conditions for pest suppression differ with climate, altitude, and soils. The
selection of tree species and associations, density and spatial arrangement, as well as shade management regimes are critical
decisions for shade strata design. Site-specific knowledge of the seasonal food web dynamics permits growers to determine
the appropriate seasonal shade management in order to further suppress pest levels. For example in a low-elevation dry coffee
zone, 35 to 65% shade promotes leaf retention in the dry season and reduces Cercospora coffeicola, weeds, and Planococcus citri; at the same time, it increases the effectiveness of microbial and parasitic organisms without contributing to increased
Hemileia vastatrix levels or reducing yields. In these conditions, shade should be at a maximum early in the dry season and at a minimum by
the middle of the rainy season. Further research is needed on: the effects of individual tree species on the food web; the
role of canopy architecture for coffee vigor, photosynthesis, leaf drying, pest susceptibility, and pruning regimes; and on
simple observation methods and decision criteria for farmer management of tree-coffee-food web interactions.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
100.