Metabolic responses of tea (Camellia sinensis L.) to the insecticide thiamethoxam     

Weiting Jiao  Ping Zhang  Chuanjian Cui  Min Yan  Qing X. Li  Yongfeng Tang  Nan Zhang  Xinyi Wang  Ruyan Hou  Rimao Hua 《Pest management science》2023,79(10):3570-3580

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Effects of Bacillus amylolyticus on Rumen Dry Matter Digestibility,Fermentation Parameters and Metabolites of Dairy Cows北大核心CSCD     

李玉琴黄新高鹏翔赵小博王慧蒋林树 《动物营养学报》2023,(1):311-322

This experiment was conducted to study the effects of Bacillus amylolyticus on rumen dry matter digestibility, fermentation parameters and metabolites of dairy cows. Experiment 1: six dairy cows with permanent fistula and had the similar parity (2 to 3 fetuses), body weight [(662 ±57) kg], lactation days [(160 ± 22) d] and milk yield [(36.1 ±3.8) kg / d], were randomly divided into 3 groups with 2 cows per group. Using 3 ×3 Latin square design, each group was extra fed 0 (control group), 5 ×109 and 5 ×1010 CFU / d Bacillus amylolyticus, the trial period was 3 periods, 13 days for each period, including 10 days for the pre-trial period and 3 days for the trial period. At the beginning of the trial period, the rumen dry matter digestibility of cows was measured by nylon bag method. Experiment 2: thirty dairy cows with similar parity [(2.5 ±0.3) fetuses], initial body weight [(559.2 ± 7. 4) kg], milk yield [(35. 2 ± 1. 5) kg / d] and lactation days [(99 ± 22) d] were randomly divided into three groups with 10 cows in each group. Cows in the 3 groups were extra fed with 0 (control group), 5 ×109 and 5 ×1010 CFU / d Bacillus amylolyticus, respectively. The pre-trial period was 10 days and the trial period was 42 days. The rumen fluid was collected on the last day of the trial period, and the rumen fermentation parameters and metabolites were determined. The results showed as follows: compared with the control group, 1) supplementary feeding of 5 × 1010 CFU / d Bacillus amylolyticus could significantly improve the rumen dry matter digestibility of dairy cows at 12, 24, 36, 48 and 72 h (P <0.05), supplementary feeding of 5 ×109 CFU / d Bacillus amylolyticus could significantly improve the rumen dry matter digestibility of dairy cows at 36 and 48 h (P <0.05); 2) supplementary feeding of 5 ×109 CFU / d Bacillus amylolyticus could significantly increase the contents of isobutyric acid, butyric acid, isovaleric acid, valeric acid, total volatile fatty acid and microbial protein in the rumen of dairy cows (P < 0. 05), supplementary feeding of 5 × 1010 CFU / d Bacillus amylolyticus could significantly increase the contents of isobutyric acid and isovaleric acid in the rumen of dairy cows and significantly reduce the rumen acetic acid / propionic acid (P < 0. 05), supplementary feeding of 5 ×109 and 5 ×1010 Bacillus amylolyticus had no effects on rumen pH and ammonia nitrogen content (P >0.05); 3) eleven metabolic pathways related to differential metabolites were detected, and ascorbic acid and alginate metabolism were significantly enriched (P < 0. 05) . In conclusion, Bacillus amylolyticus can increase the rumen dry matter digestibility, and improve the rumen fermentation function of dairy cows by affecting the content of rumen metabolites. By comprehensive analysis, supplementary feeding of 5 × 109 CFU / d Bacillus amylolyticus can achieve better effect. © 2023 Authors. All rights reserved.  相似文献   

Effects of Compound Plant Nutrients on Rumen Fermentation Parameters,Rumen Microbiota and Fatty Acid Composition of Longissimus dorsi Muscle in Finishing Small Tail Han Sheep北大核心CSCD     

王园  王文文  杨毅  高畅  郭焘  段婷  刘娜  安晓萍  齐景伟 《动物营养学报》2023,(1):380-390

This study was conducted to investigate the effects of compound p1ant nutrients (CPN) on rumen fermentation parameters, rumen microbiota and fatty acid composition of longissimus dorsi musc1e in finishing sma11 tai1 Han sheep. Sixteen 4-month-o1d finishing sma11 tai1 Han sheep with an initia1 body weight (BW) of (24.18±0.31) kg were random1y divided into two groups, name1y, with 8 rep1icates per group and 1 sheep per rep1icate. The sheep in the contro1 group were fed a basa1 diet, whereas the sheep of the contro1 group (CPN group) was fed the basa1 diet supp1ementation with 3‰ CPN. The experiment 1asted for 97 days after 7 days adaption. The resu1ts showed as fo11ows: compared with the contro1 group, 1) adding CPN decreased the concentration of ammonia nitrogen (NH3-N) (P<0.05); 2) CPN supp1ementation affected beta diversity of rumen microbiota; 3) the re1ative abundance of Acidobacteriota, Erysipe1otrichaceae_UCG-002, Lactobacillus, and Megasphaera were enhanced by adding CPN (P<0.05), whereas, the re1ative abundance of Bacteroidetes and Prevotella was 1ower (P<0.05); 4) the supp1ementation of CPN had no significant effect on fatty acid composition of longissimus dorsi musc1e of fattening sma11-tai1ed Han sheep (P>0.05); 5) the contents of tota1 MUFA, C18:1n9c, C14:1, C16:1, C18:2n6c, C18:3n3 and n-3PUFA in the longissimus dorsi musc1e were corre1ated with the re1ative abundance of Megasphaera, Erysipe1otrichaceae_UCG-002, Succiniclasticum and Ruminococcus (P<0.05). In conc1usion, CPN can regu1ate the rumen microbiota structure and reduce the rumen NH3-N concentration of fattening sma11-tai1ed Han sheep. In production practice, CPN can be used as a rumen eco1ogica1 regu1ator. © 2023 Authors. All rights reserved.  相似文献   

A mathematical model for border irrigation II. Vertical and horizontal recession phases     

V. P. Singh  F. X. Yu 《Irrigation Science》1987,8(3):175-190

Summary This paper, second in a series of three, develops a mathematical model, using the volume balance approach, to simulate vertical and horizontal recession of border irrigation. An equation is proposed for computing Manning's roughness factor N in both laminar and transitional flow regimes in recession phases. The model has four parameters which can be determined experimentally. Experimental data from ten vegetated as well as nonvegetated borders were used to verify the model. Average difference (AD) between calculated and observed vertical recession times was less than 4.4 min, and between calculated and observed horizontal recession times less than 4.6 min for the ten experimental data sets. Average relative error (ARE) in computed horizontal recession was less than 13% for these data sets. The model was found to be especially accurate for Reynold's number between 1,800 and 2,500.  相似文献   

生物质资源高压连续输送的研究   总被引：1，自引：0，他引：1  

吕秀阳  夏文莉  刘田春  SAKODA Akiyoshi  SUZUKI Motoyuki 《农业机械学报》2001,32(3):27-30

建立了近中试规模的生物质资源高压连续输送装置，通过将生物质资源与水混成浆料的方法实现了生物质资源的高压连续输送、浆料的固含量可达10％（wt)以上，压力可达40MPa，最大浆料供应量为2．4L／h。  相似文献   

内燃机排气成分动态检测方法的研究     

张惠明  汪燕  张宏伟  李万众  吕筱萍  张宇 《农业机械学报》2001,32(3):1-3

介绍了采用飞行时间质谱仪动态测量内燃机排气成分的方法。提出了实现动态检测的系统方案，研制开发了高速数据采集系统，给出了性能试验结果。测量并识别了质量数相近的N2和C2H4的谱图，给出了废气成分浓度的动态变化曲线。  相似文献   

变螺距诱导轮流场的数值模拟   总被引：2，自引：0，他引：2  

孔繁余  吕毅  黄建军  孙建 《农业机械学报》2007,38(10):45-48

在泵叶轮进口前置变螺距诱导轮能有效地提高泵机组的抗汽蚀性能。基于CFD技术,采用Fluent软件对变螺距诱导轮进行几何建模、选定边界条件等,数值模拟计算其内部流场。结合变螺距诱导轮的实例,给出了变螺距诱导轮内部速度与压力的分布情况以及粒子流动迹线图,得到了其内部流场的主要特征。  相似文献   

Contribution of sewage sludge to erosion control in the rehabilitation of limestone quarries     

X. Sort  J. M. Alcaiz 《Land Degradation \u0026amp; Development》1996,7(1):69-76

The aim of this study was to evaluate the effects of high doses of municipal sludge on soil aggregation and to assess its value for soil erosion reduction, both under natural and in simulated rainfall conditions. Doses of 200 and 400 Mg ha⁻¹ sewage sludge (dry weight) were applied to the soil of experimental plots situated on a 28 degree slope. Two sludge application procedures were tested: pre-mixing into the soil before disposal on the slope, and direct application on the soil surface. Sheet erosion was measured by collecting the sediment carried down to a Gerlach trough situated at the base of the plots. Simulated rainfall, with an intensity of 64 mm h⁻¹, was applied to evaluate soil erodibility. When the soil had no vegetation, the erosion measured on plots treated with sludge represented less than 10 per cent of the erosion from the control plot. Even when the vegetation was well developed, the erosion was also lower in the plots where sludge had been applied. In simulated rainfall, the soil loss was inversely proportional to the sludge dose, and when sludge was applied directly on the soil surface the erosion rates and particle mobilization caused by raindrop impact were minimal. Sludge amendments increase infiltration rates and improve soil structure, increasing the mean weight diameter of aggregates and their water resistance.  相似文献   

复合硅改性热处理杨木的制备及性能   总被引：1，自引：1，他引：0  

刘强强  吕文华  石媛  杜浩佳 《北京林业大学学报》2021,43(1):136-143

[目的]针对木材树脂改性剂释放甲醛不环保,无机改性材吸湿性高等问题,将廉价易得的硅石粉溶液化,再有机杂化,制得高渗透、环保、防火的水溶性木材复合硅改性剂,通过真空加压浸渍处理和热处理联合改性,可以有效提高木材的物理力学和阻燃等性能.[方法]分别制备硅油复合硅改性剂(SC2)和偶联剂杂化硅改性剂(HS2),对人工林杨木进...  相似文献   

杭椒采收期内辣椒素类物质和维生素C的动态变化          下载免费PDF全文

龚翔宇  饶帅琦  吕晓菡  杨静  祝彪 《浙江农林大学学报》2020,37(5):950-956

  目的  研究杭椒Capsicum annuum ‘Hangzhou Jizhua’בJilin Zaojiao’果实辣椒素、维生素C等物质在采收期的动态变化,以确定最佳采收期。  方法  选取4个常见杭椒品种,采用高效液相色谱法分别测定开花后14、21、28、35、42、49、56 d采收的果实中辣椒素、二氢辣椒素和维生素C以及干物质质量分数。  结果  采收期内4个杭椒品种果实辣椒素类物质质量分数不同,品种间差异显著(P＜0.05);维生素C质量分数和干物质相对含量随果实成熟度增加而升高。  结论  花后49 d是杭椒果实最佳采收期,此时果实成熟度好,辣椒素类物质、维生素C质量分数和干物质相对含量均较高。采收期内不同品种辣椒素类物质质量变化差异大,具体采收计划应综合种植品种、市场需求和供求关系等多方面因素考虑。图4表3参27  相似文献