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1.
为验证阿散酸和洛克沙生用于生长猪的效果,于1995年4月18日至5月4日在开封进行试验.试验分3组,对照组喂基础日粮,试一组加入阿散酸70mg/kg,试二组加入洛克沙生30mg/kg.选择日龄相近的健康杜长大三元杂交猪42头,随机分为3组,每组14头.每组一栏.不限量饲喂,自由饮水.预试1周后进入试验,正试17d.结果表明,阿散酸和洛克沙生组日增重分别比对照组提高14.2%和11.5%,每千克增重分别少耗料0.79kg和0.48kg. 相似文献
2.
Evaluating the accuracy of mapping weeds in seedling crops using airborne digital imaging: Avena spp. in seedling triticale 总被引:1,自引:0,他引:1
Airborne multispectral imaging has been used to map patches of Avena spp. (wild-oats) in a field of seedling triticale (X Triticosecale , Wittmack). Images of the target field were acquired using a four-camera airborne digital imaging system, recording in the infrared, red, green and blue wave-bands. Spectral information derived from images of 0.5-, 1.0-, 1.5- and 2.0-m spatial resolution were correlated with detailed on-ground weed density measurements to investigate the effect of image resolution on mapping accuracy. Comparisons between normalized-difference vegetation index (NDVI) or soil-adjusted vegetation index (SAVI) images and weed data achieved correlations of up to 71%. The highest correlation was achieved with the 0.5-m-resolution images and the lowest with the 2.0-m-resolution images. At 0.5-m resolution, NDVI images could not reliably discriminate weed populations of less than 28 weeds m–2 from weed-free regions, while SAVI images could not discriminate populations of less than 17 weeds m–2 . At 1.0-, 1.5- and 2.0-m resolution, SAVI images could not discriminate populations of less than 23 weeds m–2 , while NDVI images again demonstrated a higher discrimination threshold. Results suggest that airborne multispectral imaging could be used as part of a stratified weed sampling system. 相似文献
3.
Brunette I Rosolen SG Carrier M Abderrahman M Nada O Germain L Proulx S 《Veterinary ophthalmology》2011,14(6):365-377
Purpose The goal of this study was to report on the advantages and limitations of the pig and feline models for experimental in vivo corneal transplantation. Methods Ten healthy domestic pigs and ten healthy cats were used. Full thickness penetrating keratoplasty was performed using autologous (eight cases), allogeneic (seven cases) or human xenogeneic (three cases) tissue. In two other cases, the inflammatory response to partial thickness trephination (without transplantation) was evaluated. Eyes were assessed daily before and after surgery by slit‐lamp, pachymetry, and tonometry. A transparency score ranging from 0 (opaque graft) to 4 (clear graft) was used, based on the slit‐lamp examination. Optical coherence tomography, histology, and electron microscopy were performed postmortem. Results In the pig, the mean (±SD) transparency score for the eight full thickness grafts was 0.88 ± 0.99, ranging from 0 to 3. In the feline model, the mean transparency score for the seven uncomplicated grafts was 3.93 ± 0.19, ranging from 3.5 to 4. Both negative controls without endothelium remained opaque at all time. Intraoperative tendency for iris incarceration into the wound, rapid corneal swelling, suture cheese wiring, and postoperative intraocular inflammation were the main factors jeopardizing the functional success of the corneal transplant in the pig model. Conclusion Suboptimal functional results were obtained after full thickness corneal transplantation in the pig model, while in the feline model, the same protocol yielded uneventful surgeries and clear transplants, with functional results similar to those achieved in human subjects. 相似文献
4.
Managing soil fertility in organic farming systems 总被引:9,自引:0,他引:9
C.A. Watson D. Atkinson P. Gosling L.R. Jackson F.W. Rayns 《Soil Use and Management》2002,18(S1):239-247
Abstract. Complex relationships exist between different components of the organic farm and the quantity and quality of the end products depend on the functioning of the whole system. As such, it is very difficult to isolate soil fertility from production and environmental aspects of the system. Crop rotation is the central tool that integrates the maintenance and development of soil fertility with different aspects of crop and livestock production in organic systems. Nutrient supply to crops depends on the use of legumes to add nitrogen to the system and limited inputs of supplementary nutrients, added in acceptable forms. Manures and crop residues are carefully managed to recycle nutrients around the farm. Management of soil organic matter, primarily through the use of short-term leys, helps ensure good soil structure and biological activity, important for nutrient supply, health and productivity of both crops and livestock. Carefully planned diverse rotations help reduce the incidence of pests and diseases and allow for cultural methods of weed control. As a result of the complex interactions between different system components, fertility management in organic farming relies on a long-term integrated approach rather than the more short-term very targeted solutions common in conventional agriculture. 相似文献
5.
《Communications in Soil Science and Plant Analysis》2012,43(17):2109-2121
Organic inputs are believed to be able to increase soil phosphorus (P) availability. Natural fallow and pig slurry amendments are the two important organic inputs for agricultural soils. The purposes of the study are to investigate P accumulation and to compare the differences of P fractionation patterns as affected by natural fallow and pig slurry drip irrigation in a coastal saline soil. The study showed that P accumulation occurred mainly in upper soil profiles and that natural fallow or pig slurry drip irrigation alone would not significantly influence total P distribution in soil profiles. However, soil P fractionation demonstrated that, from bottom to top, bioavailable P content and percentage increased whereas residual P percentage declined. The percentage of extractable inorganic P was almost twice as much as that of extractable organic P. In comparison with natural fallow conditions, under pig slurry drip-irrigation conditions, the transformation efficiency of superphosphate fertilizer HCl Pi into residual P was lower whereas the transformation efficiency of superphosphate fertilizer HCl Pi into bioavailable P was higher. The higher bioavailable P percentage and lower average Corg/P ratio in a long-term pig slurry drip-irrigation plot than those in other plots indicated that long-term pig slurry drip-irrigation was more efficient in improving soil P availability than natural fallow and short-term pig slurry drip irrigation. 相似文献
6.
死猪堆肥处理的通风率选择探讨 总被引:1,自引:3,他引:1
针对生产中死猪难处理的问题,作者对死猪堆肥技术进行了试验研究。试验采用箱式堆肥方法,设定处理1、处理2、处理3的通风速率分别为300、200和100L/(m3·min),每个处理设置4个重复;堆肥箱有效容积为0.95m3,每个堆肥箱中间单层放入3头死猪(总质量30~32kg),死猪上、下和四周是由玉米秸秆和猪粪混合的堆肥物料。在北京夏季条件下的运行结果表明,各处理堆肥箱内平均温度超过55℃的时间分别为19、19和34d,处理间差异不显著;试验6周后,死猪仅剩下大部分骨骼,此时3种处理的死猪降解率分别达到(95.5±1.4)%、(94.7±1.7)%和(95.0±0.8)%,仅处理1与处理3的死猪质量(湿基)差异显著(P<0.05);试验14d后粪大肠菌群数即能满足相关标准的无害化要求;各处理堆肥物料的同一特性参数的变化规律一致,且无显著差异,堆肥结束时物料的有机质(干基)质量分数在47%~48%,全氮和全磷(干基)的质量分数达5.7%~6.4%,超过《有机肥料》标准的总养分≥5%的技术指标要求。鉴于以上试验结果,综合考虑运行成本,建议死猪箱式堆肥的通风率不大于100L/(m3·min)和堆肥时间不少于6周。死猪堆肥在无害化处理死猪的同时,将其转化成有机肥料,将为中国规模化猪场的死猪处理提供新的技术选择。 相似文献
7.
《Communications in Soil Science and Plant Analysis》2012,43(4):415-428
A field experiment was conducted for 5 years (2004–2005 to 2009–2010) covering 10 crop seasons [five wet (WS; Kharif) and five dry (DS; Rabi)] at the Directorate of Rice Research farm, Hyderabad, India, to compare the influence of organic and conventional farming systems on productivity of fine grain rice varieties, cumulative partial nutrient balance, and soil health/quality in terms of nutrient availability, physical and biological properties, and sustainability index. Two main plot treatments were with and without plant protection measures, and four subplot treatments were (1) control (CON), (2) inorganic fertilizers (CF), (3) organics (OF), and (4) inorganics + organics (integrated nutrient management, INM). During wet season, grain yields with CF and INM were near stable (5.0 to 5.5 t ha?1) and superior to organics by 15–20% during the first 2 years, which improved with OF (4.8 to 5.4 t ha?1) in the later years to comparable levels with CF and INM. However, during DS, CF and INM were superior to OF for 4 consecutive years and OF recorded yields on par with CF and INM in the fifth year. The partial nutrient balance over 10 crop seasons for N and P was positive and greater with OF and INM over CF and for K it was positive with OF alone and negative with CF and INM. There were increases in SOC and available N, P, and K by 50–58%, 3–10%, 10–30%, and 8–25% respectively, with OF, over CF at the end of 5 years. The sustainability index (SI) of the soil system was maximum with organics (1.63) and CF recorded 1.33, which was just above the minimum sustainability index of 1.30 after 5 years. Thus, organic farming needs more than 2 years to stabilize rice productivity and bring about perceptible improvement in soil quality and sustainability in irrigated rice. 相似文献
8.
The present study describes the antispasmodic activity of some fractions from the bark of Persea cordata, against guinea pig ileum contracted by acetylcholine and histamine. Hexane and dichloromethane fractions demonstrated the most promising biological effects, having similar potency to that of papaverine, a well-known antispasmodic agent. 相似文献
9.
总结阿片受体类型的研究进展,介绍4种主要类型受体的功能。动物脑中阿片受体的数量以及它们与阿片配体亲和力的改变能够对脑功能的阿片控制或内分泌系统的中枢神经控制产生影响。为明确猪脑中阿片受体的变化,阐述了阿片受体在猪脑中的个体发育特点。 相似文献
10.
《东北农业大学学报(英文版)》2016,(3):23-30
To investigate the performance of organic and inorganic phosphorous on growth of Roselle(Hibiscus sabdariffa L.),an experiment was carried out at Newly Developmental Farm(NDF),Horticulture Section,the university of Agriculture Peshawar,Pakistan,during 2012.The experiment was laid out in a Randomized Complete Block Design(RCBD) with split plot arrangement and replicated three times.The chemical fertilizer Single Super Phosphate(SSP) was used as inorganic source of phosphorus,while Organic Phosphate(OP) from organic product produced by Niha corporation containing 20%organic mineralized P_2O_5,was used as the source of organic phosphorous.Both the sources of fertilizer were applied at the rate of 10,20,30 40 and 50 kg · hm~(-2) and control.The statistical analysis of data revealed that both the sources and levels of phosphorus significantly affected most of the growth parameters of Roselle except germination percentage and survival percentage.Plant height(112.09 cm),numbers of leave plant~(-1)(177.87),numbers of branch plant~(-1)(4.08),leaf areas(126.60 cm~2),days to flowering(142.83),fresh flower weight(2.56 g),fresh calyx weight(1.70 g),dry calyx weight(0.43 g),numbers of calyces(94.10),numbers of root plant~(-1)(11.03),root length(22.67 cm)and root weight(27.50 g) were observed in plants fertilized with organic source of phosphorous.Phosphorous levels significantly affected all of the parameters except germination percentage and survival percentage.The maximum plant height(124.39 cm),numbers of branches(5.32),numbers of leave plant~(-1)(204.89),leaf areas(148.14 cm~2),fresh flower weight(3.32 g),fresh calyx weight(2.04 g),dry calyx weight(0.51 g),numbers of calyces(105.30),numbers of root plant~(-1)(12.78),root length(24.50 cm) and root weight(29.94 g) were observed in plants fertilized with 40 kg·hm~(-2) phosphorous and the maximum numbers of days to flowering(148.17) were observed in the control plants.It was concluded from the experimental results that organic phosphorous at the rate40 kg·hm~(-2) would be used for better production of Roselle under agro-climatic condition of Peshawar. 相似文献