绿色富硒生物猪饲料中AFB₁达标生产工艺优化研究     

郑威  卢婵  余侃  黄思思  余锦平  刘金龙  程水源  魏金涛  李良华  刘欋霄  郑倬  田国政  周光来 《中国饲料》2021,(5):84-90

饲料中黄曲霉毒素(AFB₁)容易超标,检出率达80%~100%,毒性大,具强致癌性,可抑制生猪免疫机能,降低动物生产性能,引起动物继发感染,还会在动物产品中残留而威胁人类健康,给生猪养殖带来经济损失,降低猪肉食品安全性。本文通过使用先进固体发酵系统设备和益生菌发酵技术,采用单因素试验和响应面中试优化,获得发酵降解猪饲料AFB₁的最佳工艺参数为硒浓度0.3 mg/kg,发酵时间12 h,量子波强度30 Hz,益生菌菌种组合CGMCC NO.17328混合CGMCC NO.15611。该工艺将猪饲料AFB₁量从63.41μg/kg降解到2.98μg/kg,降解率达到95.30%,AFB₁含量达到国家饲料安全标准。生产工艺适合养猪场低成本快速生产AFB₁达标猪饲料。  相似文献   

天山云杉人工幼林树冠结构及其在林分间伐中的应用研究     

罗明灿  张瑛山 《新疆农业大学学报》1994,(4)

本文对天山云杉人工幼林树冠结构以及树冠结构与林木之间的关系进行了研究，并基于生物学原理，在确定有效树冠的法础上，通过决定林木能力的树冠特征对其人林分间伐中的应用进行了初步研究。  相似文献   

浙农大A系意蜂生产性能考察试验报告   总被引：5，自引：0，他引：5  

沈基楷  肖体元 《中国蜂业》1993,(1):4-6

用杂交一代蜂群进行对比试验的结果表明,浙农大 A 系意蜂的产育力、群势增长速度、采蜜量等,与平湖意蜂和澳大利亚意蜂无显著差异或基本一致,但蜂王浆高产性能表现突出,产量比平湖意蜂高19.5%,比澳意高42.5%,而且质量指标符合国家规定和出口标准。  相似文献   

Enantioselective degradation kinetics of metalaxyl in rabbits     

Jing Qiu 《Pesticide biochemistry and physiology》2005,83(1):1-8

Metalaxyl [methyl-N-(2′-methoxyacetyl)-N-(2,6-dimethylphenyl)-d,l- alaninate] is a potent phenylamide fungicide. The (−)-(R)-isomer accounts for most of the fungicidal activity. A possible stereo and/or enantioselective kinetics of metalaxyl in rabbits was investigated by intravenous injection. The concentrations of (−)-(R)- and (+)-(S)-metalaxyl in plasma, liver, and kidney tissue were determined by HPLC with a cellulose-Tris-(3,5-dimethylphenylcarbamate)-based chiral stationary phase and gas chromatography-mass spectroscopy. After intravenous administration of racemic metalaxyl (40 mg/kg), the (+)-(S)-enantiomer levels in plasma, liver, and kidney decreased more rapidly than the (−)-(R)-isomer. The area ratio of the (−)-(R)-/(+)-(S)-enantiomer under the concentration-time curve (AUC_0 → ∞) in plasma after drug application was 1.62. The total plasma clearance value of the (+)-(S)-enantiomer was 1.53 and higher than that of the (−)-(R)-enantiomer. The [R]/[S] ratio in plasma was >1 for standard rac-metalaxyl at each time point. The other pharmacokinetic parameters of the enantiomers were also different. The results indicate substantial stereoselectivity in the degradation of metalaxyl enantiomers in rabbits.  相似文献   

反刍动物过瘤胃淀粉研究进展   总被引：4，自引：0，他引：4  

朱森阳  汪国和  贾志海 《中国饲料》2005,(13):2-4

过瘤胃淀粉是高产反刍动物葡萄糖的重要来源之一。本文阐述了过瘤胃淀粉在反刍动物营养中的作用,以及提高饲料过瘤胃淀粉比例的处理方法,并根据近年来的应用研究状况,提出了过瘤胃淀粉在应用中存在的问题及今后的研究方向。  相似文献   

Influence of the physical and chemical properties of soil on the retention process of isoxaflutole and its two main derivatives     

E Beltran  H Fenet  J F Cooper†  & C M Coste† 《Weed Research》2002,42(5):385-393

Isoxaflutole is a new pre‐emergence herbicide for use in maize and sugarcane. Its two main derivatives are a diketonitrile derivative, the 2‐cyano‐3‐cyclopropyl‐1‐(2‐methanesulfonyl‐4‐trifluoromethylphenyl)propan‐1,3‐dione, named DKN, and a benzoic acid derivative, the 2‐methanesulfonyl‐4‐trifluoromethylbenzoic acid, named BA. The adsorption/desorption processes have never been studied for isoxaflutole (IFT) at high concentrations nor for BA, and the present work aimed at completing the knowledge of the behaviour of these three molecules in conditions close to those encountered in the context of agricultural use. The adsorption/desorption study was conducted on seven soils of different physical and chemical properties, using the batch equilibrium technique. During the experiments, IFT was chemically converted into DKN in a continuous manner. This reaction appeared to be dependent on the pH of the soil and was taken into account in the calculations of the adsorbed and desorbed amounts. The adsorption isotherms obtained were predominantly C‐shaped for IFT and DKN and S‐shaped for BA, but some differences appeared on a few soils. They fitted well the Freundlich equation, and the values of the Freundlich coefficient K_fa showed that, whatever the soil, IFT was more adsorbed than its two derivatives. The main parameter influencing the adsorption of IFT appeared to be the organic matter content, whereas this effect was not evident for DKN and BA. No correlation was found between the extent of adsorption and either clay content or pH of the soil, for the three molecules.  相似文献   

环境条件和微生物对灭线磷降解的影响   总被引：15，自引：2，他引：15  

吴春先  吕潇  慕卫  慕立义  陈子雷 《农药学学报》2002,4(1):45-51

环境条件和微生物影响灭线磷在土壤中的降解。随着土壤含水量和温度的增加,灭线磷的降解速度加快;微生物对灭线磷的降解有显著影响,30℃、含水量为40%条件下,未灭菌土中灭线磷的半衰期为16.6 d,灭菌土中灭线磷的半衰期为31.6 d;有机质对灭线磷的降解也有显著影响,有机质含量高,有利于灭线磷的降解;灭线磷在碱性土壤中的降解快于在酸性土壤中;30℃、含水量为40%条件下,灭线磷在3种土壤中的降解速度为:东北黑土＞广东红土＞山东砂壤土。  相似文献   

干旱区绿洲荒漠交错带土地退化及生态重建   总被引：20，自引：15，他引：20  

唐立松  张佳宝  程心俊  高新莲  杜恩昊 《干旱区研究》2002,19(3):43-48

由于经济的发展，土地资源受到越来越大的压力。当这种压力超过了土地资源的承载能力，就导致了土地退化的发生。作为陆地生态系统的基础，土地资源的退化表现为：土壤肥力降低，生物多样性降低，以及伴随的经济发展的落后。当前世界范围内对土地退化的治理，基本方法仍是基于生态学理论的生物方法。但对土地退化的恢复与生态系统的重建的研究，需要经过谨慎设计的长期实验。绿洲荒漠交错带的重要性，不仅表现为是绿洲的保护屏障，而且在绿洲经济的发展中也起到巨大的作用。通过对国内外大量研究的回顾，讨论了在不同地区进行的长期实验所采用的方法。有人为因素参与的退化土地恢复与生态重建，可以在短期内取得明显效果。产生土地退化的原因，不仅仅是土地资源特点与自然环境这样一些自然因素，还包括一些社会与经济因素。因此退化土地的恢复与生态重建的成功，需要一种考虑自然、社会和经济因素的综合的方法。  相似文献   

Predicting effective doses for the joint action of two fungicide applications   总被引：1，自引：0，他引：1  

N. D. Paveley †  J. M. Thomas  T. B. Vaughan  N. D. Havis  D. R. Jones 《Plant pathology》2003,52(5):638-647

A function was derived to predict fungicide efficacy when more than one application of a single active ingredient is made to a crop, given parameters describing the dose–response curves of the component single-spray applications. In the function, a second application is considered to act on that proportion of the total pathogen population which was uncontrollable at the time of the first application (represented by the lower asymptote of the dose–response curve for the first treatment), plus any additional part of the population which survived the first application as a result of a finite dose being applied. Data to estimate the single-spray dose–response curve parameters and validate predictions of two-spray programme efficacy were obtained from separate subsets of treatments in four field experiments. A systemic fungicide spray was applied to wheat at a range of doses, at one or both of two times (t₁ and t₂), in all dose combinations. Observed values of the area under the disease progress curve (AUDPC) for septoria leaf blotch (Mycosphaerella graminicola) were used to construct response surfaces of dose at t₁ by dose at t₂ for each culm leaf layer. Parameters were estimated from single-spray and zero-dose treatment data only. The model predicted a high proportion (R² = 71–95%) of the variation in efficacy of the two-spray programmes. AUDPC isobols showed that the dose required at t₂ was inversely related to the dose at t₁, but the slope of the relationship varied with the relative timings of t₁ and t₂ in relation to culm leaf emergence. Isobols were curved, so the effective dose – the total dose required to achieve a given level of disease suppression – was lower when administered as two applications.  相似文献   

有效碳数法研究及其在农药气相色谱分析中的应用   总被引：2，自引：0，他引：2  

刘绍仁  叶纪明 《农药科学与管理》1997,18(4):5-9

有机化合物结构与其所含有的有效碳数有一定的关系，本文给出了２０类结构化合物及其所含有有效碳数的关系，并对理论计算值和实测值进行了比较，结果十分接近，利用有效碳数法可以设计农药分析实验方案和无标样的情况下测定农药杂质含量。  相似文献