欧盟、美国和日本加工农产品中农药残留评估现状

本文介绍了欧盟、美国和日本评估加工农产品中农药残留的数据要求和试验准则,以及开展膳食摄入风险评估和推荐农药最大残留限量(MRL)的方法,汇总了用于农药残留评估的加工农产品及其分类,分析了加工农产品中农药MRL制定现状,为进一步提高我国相关领域技术提供借鉴。比较分析结果表明,欧盟和美国在农药登记资料要求中明确提出了加工试验数据要求并且制定了相应的试验准则,美国在试验准则中描述了加工农产品中农药MRL的推荐原则;美国和日本制定了一定数量的加工农产品中农药MRL,欧盟建立了适用于监管农药MRL的加工因子数据库;欧盟、美国和日本均在相关法规中规定了加工农产品中农药残留的合规性判定。     

氟吡呋喃酮与8种杀虫剂复配对温室白粉虱的联合毒力

为了筛选出对温室白粉虱高效的农药复配组合,本试验选择9种杀虫单剂对田间采集的温室白粉虱进行了毒力测定,并利用共毒因子和共毒系数对氟吡呋喃酮与8种杀虫剂复配组合的联合毒力进行评价,同时对筛选出的药剂进行田间药效试验。结果表明：杀虫单剂毒力测定中,LC₅₀最低的为鱼藤酮,最高的为螺虫乙酯,48 h LC₅₀分别为0.43μg/mL和78.59μg/mL;毒力大小顺序为鱼藤酮>氟啶虫胺腈>除虫菊素>苦参·印楝素>d-柠檬烯>氟吡呋喃酮>啶虫脒>高效氯氰菊酯>螺虫乙酯。共毒系数大于120的复配组合为氟吡呋喃酮与d-柠檬烯5∶1、氟吡呋喃酮与苦参·印楝素1∶2和1∶5,共毒系数分别为268.31、247.80和241.46,LC₅₀分别为5.76、4.51μg/mL和4.34μg/mL。氟吡呋喃酮与d-柠檬烯5∶1复配增效作用明显,为最佳配比。田间药效试验表明,10 d后,17%氟吡呋喃酮可溶液剂与1%苦参·印楝素乳油、5%d-柠檬烯可溶液剂复配对温室白粉虱的防效达到83.5%～83...     

Effect of multi-enzymes in combination with a direct-fed microbial on performance and welfare parameters in broilers under commercial production settings

The objective of this study was to determine the response of broilers to the combination of multi-enzymes and direct-fed microbial (DFM) under commercial production settings. A total of 7,000 1-day-old male broilers (Ross 308) were distributed over 10 pens (700 broilers/pen). Two dietary treatments were tested using complete randomized design, including a control diet and a test diet with addition of multi-enzymes (xylanase, amylase, and protease (XAP)] and DFM (a combination of spores from 3 strains ofBacillus amyloliquefaciens). Pelleted diets were offered ad libitum in 3 phases and water was freely available. During starter and grower phases (0 to 21 d), the enzyme and DFM combination resulted in improved FE (P < 0.05). During the finisher phase, higher feed intake and BW gain (P < 0.05) were observed for the test group. Overall, there were significantly higher feed intake, BW gain, and lower water-to-feed ratio in test group compared to the control group. This was related to improved (P < 0.05) modified production efficiency factor which was calculated based on final BW, survival rate, feeding period, and mortality-weight-corrected FCR. The test group had improved litter quality and a reduced foot-pad lesion score compared to the control. In addition, there was a tendency (P < 0.1) of reducingClostridium perfringens population in cecal digesta and higher lactic acid content in the ileal digesta, when expressed on an as-is basis, in the test group. In this study, we demonstrated that using a multi-enzymes and DFM combination in the diet for broilers can result in improved FE in starter/grower phases and animal welfare parameters, and lead to improved production efficiency under commercial settings.     

Genetic characterization of bovine viral diarrhea virus strains in Beijing,China and innate immune responses of peripheral blood mononuclear cells in persistently infected dairy cattle

To acquire epidemiological data on the bovine viral diarrhea virus (BVDV) and identify cattle persistently infected (PI) with this virus, 4,327 samples from Holstein dairy cows were screened over a four-year period in Beijing, China. Eighteen BVD viruses were isolated, 12 from PI cattle. Based on genetic analysis of their 5''-untranslated region (5''-UTR), the 18 isolates were assigned to subgenotype BVDV-1m, 1a, 1d, 1q, and 1b. To investigate the innate immune responses in the peripheral-blood mononuclear cells of PI cattle, the expression of Toll-like receptors (TLRs), RIG-I-like receptors, interferon-α (IFN-α), IFN-β, myxovirus (influenza virus) resistance 1 (MX1), and interferon stimulatory gene 15 (ISG15) was assessed by qPCR. When compared with healthy cattle, the expression of TLR-7, IFN-α, and IFN-β mRNA was downregulated, but the expression of MX1 and ISG-15 mRNA was upregulated in PI cattle. Immunoblotting analysis revealed that the expression of interferon regulatory factor 3 (IRF-3) and IRF-7 was lower in PI cattle than in healthy cattle. Thus, BVDV-1m and 1a are the predominant subgenotypes in the Beijing region, and the strains are highly divergent. Our findings also suggest that the TLR-7/IRF-7 signaling pathway plays a role in evasion of host restriction by BVDV.     

大豆饲料产品中主要抗营养因子含量的检测与分析

本试验旨在应用间接竞争酶联免疫吸附测定(ELISA)法以及色谱法测定不同加工工艺的大豆饲料产品中主要大豆抗营养因子大豆球蛋白、β-伴大豆球蛋白和胰蛋白酶抑制因子以及大豆中蔗糖、棉子糖和水苏糖的含量。采用ELISA试剂盒对国内257份大豆制品中大豆球蛋白、β-伴大豆球蛋白和胰蛋白酶抑制因子含量进行检测与分析;利用离子色谱建立了大豆产品中蔗糖、棉子糖和水苏糖的灵敏、准确的同步测定法,并对国内92份大豆制品中寡糖含量进行检测与分析。结果表明:发酵豆粕、膨化大豆、大豆浓缩蛋白和大豆分离蛋白中大豆球蛋白、β-伴大豆球蛋白和胰蛋白酶抑制因子含量相对较低;本试验所建立的离子色谱同步测定大豆中蔗糖、棉子糖和水苏糖的方法具有灵敏度和准确性高、重现性好的优点,适用于大豆寡糖的测定;通过对实际样品的检测和分析,发现发酵豆粕和大豆分离蛋白中3种大豆寡糖含量均相对较低。本试验所得到不同加工工艺的大豆产品中主要抗营养因子含量的相关数据将为大豆在畜禽饲料中的高效利用提供很好的技术支撑。     

遮荫对早熟禾产量因子的影响

测定了草地早熟禾5个不同品种在不同遮荫处理下的单株成穗数、单穗粒数、千粒质量及产量。结果表明:遮荫条件下品种润草1号和09-2早熟禾单株成穗数、单穗粒数、千粒质量及产量性状均表现较为优良,表明润草1号和09-2是较耐荫的品种。其中,"润草1号"在遮光率77%时单株产量与其他品系差异显著,在遮光91%仍有少量抽穗。     

血清中不同甘露(聚)糖结合凝集素浓度的绵羊感染绵羊肺炎支原体后免疫因子表达的变化

为研究中国美利奴羊不同甘露(聚)糖结合凝集素(MBL)浓度感染绵羊肺炎支原体(MO)的免疫因子水平变化,本研究选择血清中MBL高、低浓度的绵羊各6只(感染组和对照组各3只),感染组人工感染MO,分别在人工感染前和感染后不同时间,采用荧光定量PCR法检测血液中血清因子及补体表达水平。结果显示,不同MBL浓度的绵羊人工感染后MBL m RNA水平呈下降趋势,MBL高浓度促炎因子IL-2和IFN-γ的m RNA表达水平较高,抗炎因子IL-4的m RNA表达水平在感染后1 d升高,此后开始下降,而IL-4的m RNA水平在14 d后有所升高;MBL低浓度羊感染后其TNF-α的m RNA水平显著升高,随炎症的缓解,逐渐降低;补体C1和C3的m RNA在感染后表现出不同的变化,MO感染可以激活补体途径。本研究结果表明,低血清MBL浓度与绵羊支原体肺炎具有一定的相关性,MBL不同浓度组之间其IL-2、IL-4、TNF-α、IFN-γ、补体C1、C3水平存在差异,低浓度MBL的绵羊更易发生比较严重的炎症反应。     

动物运输应激源与应激反应影响因子研究进展

动物的运输是畜牧业的重要生产环节,但运输活动带来的动物福利问题也越来越受到关注。开展动物运输应激源和应激反应影响因子的研究,对深入认识动物运输应激本质和提出解决方案乃至相关立法具有重要意义。论文对前人开展的动物运输应激源(拥挤、禁食禁水、气温、装卸、颠簸等)的分离研究和应激反应影响因子(运输距离和运输时间、年龄和经验、性情、恐惧信息素)的研究进行了回顾整理,并分析了争议的原因,为动物运输应激领域研究提供参考或指出新的研究方向。     

Hypoxia inducible factor 1α expression and effects of its inhibitors in canine lymphoma

Hypoxic conditions in various cancers are believed to relate with their malignancy, and hypoxia inducible factor-1α (HIF-1α) has been shown to be a major regulator of the response to low oxygen. In this study, we examined HIF-1α expression in canine lymphoma using cell lines and clinical samples and found that these cells expressed HIF-1α. Moreover, the HIF-1α inhibitors, echinomycin, YC-1 and 2-methoxyestradiol, suppressed the proliferation of canine lymphoma cell lines. In a xenograft model using NOD/scid mice, echinomycin treatment resulted in a dose-dependent regression of the tumor. Our results suggest that HIF-1α contributes to the proliferation and/or survival of canine lymphoma cells. Therefore, HIF-1α inhibitors may be potential agents to treat canine lymphoma.     

基于 DEA 和 Malmquist 指数的广东省渔业效率研究

【目的】分析掌握广东渔业的产出效率,为发展可持续的低耗高产渔业提供数据参考。【方法】基于数据包络分析（DEA）及 Malmquist 指数,对 2011—2022 年期间广东渔业综合技术效率和全要素生产率指数及其分解进行测算和分析,并与全国平均值进行对比。【结果】广东渔业综合技术效率每年均高于全国平均水平,但2011—2014 年、2018—2019 年和 2021 年广东渔业规模报酬呈现递减。通过对广东水产养殖和水产品捕捞的综合技术效率分别进行测算,发现 2011—2022 年期间广东水产养殖的综合技术效率较高,除 2013 年和 2014 年外,均为DEA 有效。将 DEA 无效年份的广东水产养殖和水产品捕捞在生产前沿面上的投影调整为 DEA 有效,结果显示,2013 年和 2014 年广东水产养殖投入的冗余率分别为 5.98% 和 10.46%,而 2011—2014 年、2018—2019 年和 2021年广东水产品捕捞投入的冗余率在 39.73%~74.27% 之间,说明水产品捕捞的过度投入以及由此引发的捕捞综合技术效率低下是造成 2011—2014 年、2018—2019 年和 2021 年广东渔业规模报酬递减的主要原因。广东渔业的技术进步和全要素生产率上升幅度与全国平均水平相差较远,全要素生产率和技术进步指数均比全国平均增幅低 4.7%,说明广东省在渔业技术进步方面有较大提升空间。【结论】建议广东加大渔业科技的投入力度,加强渔业技术创新,以促进渔业技术进步和提高全要素生产率;加快渔业产业结构调整,合理布局养殖和捕捞规模,以解决广东渔业规模报酬递减的问题;加强渔业资源保护和增殖放流,利用自然生产力增加可捕捞渔业资源;加强水产良种创制及养殖新模式和新技术的开发,进一步拓展水产养殖空间和提高水产养殖的产出效率。