肉牛呼吸系统疾病的诊断与防治

肉牛呼吸系统疾病是由环境因素(如断奶、运输、混群、阉割、拥挤和通风不良)、宿主自身因素和病原体等诸多因素相互作用引发的呼吸系统综合症。罹病牛日增重减少、饲料转化率降低、胴体质量下降和防治成本增加。在肉牛养殖业中,该病发病率和死亡率均较高,对世界肉牛养殖业造成巨大经济损失。文章介绍了发达国家和我国对肉牛呼吸系统疾病诊断、治疗和预防的近期研究进展,旨在为其有效防治提供参考。     

Bats adjust temporal parameters of echolocation pulses but not those of communication calls in response to traffic noise

Many studies based on acute short‐term noise exposure have demonstrated that animals can adjust their vocalizations in response to ambient noise. However, the effects of chronic noise over a relatively long time scale of multiple days remain largely unclear. Bats rely mainly on acoustic signals for perception of environmental and social communication. Nearly all previous studies on noise‐induced vocal adjustments have focused on echolocation pulse sounds. Relatively little is known regarding the effects of noise on social communication calls. Here, we examined the dynamic changes in the temporal parameters of echolocation and communication vocalizations of Vespertilio sinensis when exposed to traffic noise over multiple days. We found that the bats started to modify their echolocation vocalizations on the fourth day of noise exposure, with an increase of 42–91% in the total number of pulse sequences per day. Under noisy conditions, the number of pulses within a pulse sequence decreased by an average of 17.2%, resulting in a significantly slower number of pulses/sequence (P < 0.001). However, there was little change in the duration of a pulse sequence. These parameters were not significantly adjusted in most communication vocalizations under the noise condition (all P > 0.05), except that the duration decreased and the number of syllables/sequences increased in 1 type of communicative vocalization (P < 0.05). This study suggests that bats routinely adjust temporal parameters of echolocation but rarely of communication vocalizations in response to noise condition.     

浙江省规模化生猪养殖业节水减排补偿机制研究

本文旨在探索以补偿手段为主体的规模化生猪养殖业节水减排激励机制。在构造理论框架阐释畜禽养殖业节水减排的补偿机制后,通过实地调研和回归分析确认规模化生猪养殖户节水减排的规模经济效应。结果表明:畜禽养殖业节水减排的补偿机制是指在既定目标下,将当期的节水量与减排量作为下期的节水减排补贴,同时提高单位水价与单位排污费,以经济效益为诱因,激励养殖户采纳节水减排技术,直到形成合理的价格后,逐步取消补贴,最终使补贴激励转化为价格调控;规模化生猪养殖户节水减排的规模经济效应表现为,随着养殖规模的扩大,预计节水量和预计减排量均先减速递增,呈现出规模经济的特征,达最大值后加速递减,呈现出规模不经济的特征。因此,应从"梯价补贴"政策和配套措施安排2个方面设计规模化生猪养殖业节水减排补偿制度。     

水煮和提取处理对中草药干物质消化率和小肠可消化蛋白质的影响

研究水煮和提取处理对中草药干物质消化率和小肠可消化蛋白质的影响,揭示提取过程对营养价值影响的作用机理,对于客观评定中草药提取残渣的营养价值具有重要意义。采用尼龙袋试验分别测定黄芪、麦芽和甘草3种原料及其经水煮和提取处理后产物的瘤胃降解动力学参数,并分别估算其主要养分在瘤胃的有效降解率(effective degradability,ED);采用移动尼龙袋试验分别测定3种原料及其经水煮和提取处理后产物瘤胃未降解干物质(nondegradable dry matte,UDM)和未降解蛋白质(nondegradable protein,UDP)的小肠消化率(intestinal digestibility,Idg),在此基础上分别估算其干物质消化率(dry matter digestibility,DDM)和小肠可消化粗蛋白质(intestinal digestible crude protein,IDCP)含量。结果表明:1)3种中草药经水煮和提取处理后产物的EDDM(effective degradability of dry matter)和EDCP(effective degradability of crude protein)均分别显著低于其未处理原料(P<0.05),但EDNDF(effective degradability of NDF)和EDADF(effective degradability of ADF)均分别显著高于其未处理原料(P<0.05);2)3种中草药经水煮和提取处理后产物的IdgUDM(intestinal digestibility of UDM)和IdgUDP(intestinal digestibility of UDP)均显著高于其未处理原料(P<0.05);3)水煮处理显著提高了3种中草药处理后产物的DDM(P<0.05),显著提高了麦芽处理后产物的IDCP和IDCP/CP,提取处理显著提高了麦芽提取残渣的DDM、IDCP和IDCP/CP(P<0.05),显著降低了甘草提取残渣的IDCP和IDCP/CP和黄芪的IDCP(P<0.05)。在无特殊需求时完全没有必要对饲料进行水煮处理;麦芽提取残渣具有作为优质精饲料的营养潜力;黄芪和甘草提取残渣具有作为优质粗饲料的营养潜力。     

Development of a semi-selective medium and an immunofluorescence colony-staining procedure for the detection of Clavibacter michiganensis subsp. sepedonicus in cattle manure slurry

Various compounds and basal media were tested for their suitability to create a semi-selective medium for isolation ofClavibacter michiganensis subsp.sepedonicus (Cms) from cattle manure slurry containing c. 10⁸ colony forming units (cfu) per ml.Plating efficiency of Cms in yeast glucose mineral medium (YGM) was 104% compared with yeast peptone glucose medium. Nalidixic acid, polymyxin B sulphate and the experimental disinfectant S-0208 inhibited colony growth of cattle slurry bacteria as compared with Cms in YGM. The optimal concentration of these inhibitors in combination was determined by modified agar diffusion tests and by pour plating in 24-well tissue culture plates. The semi-selective medium YGMI consisted of YGM supplemented with nalidixic acid (2 mg/l), polymyxin B sulphate (30 mg/l) and S-0208 (125 mg/l). Plating efficiency varied for Cms between 50.9 and 69.6%, for cattle slurry bacteria between 1.8 and 2.5% and for saprophytes from potato heel end extracts between 11.5 and 27.4%.Differentiation of Cms colonies from other colonies was based on their small and bluish colony morphology in pour plates and on immunofluorescence colony-staining (IFC). IFC of a pure culture of micro colonies of Cms in YGM was possible after one day incubation (colonies c. 5 cells). Green background fluorescence in the agar gels was prevented by addition of Tween 20 (0.1%) to the washing buffer and the use of 1% agar gels. IFC of macro colonies of Cms in YGMI, visible with 4x objective magnification, was possible after 4 days. The detection level of the target organism in artificially inoculated cattle slurry in YGMI based on colony morphology varied between 1.4×10³ and 2.3×10⁴ cfu per ml of cattle slurry. Miniaturized plating combined with IFC, using wells in tissue culture plates (=16 mm), proved suitable for detection, but was c. 30 times les sensitive. The recovery of Cms was negatively correlated with the number of saprophytic colonies in the agar plates (R ²=0.74).     

影响紫花苜蓿花药培养因素的探讨与分析

从外植体的选取时期及处理、培养基及激素组合、培养条件等多方面分析,影响紫花苜蓿花药培养的因素,并对花粉植株倍性鉴定、驯化移栽和花粉植株的遗传稳定性进行了初步探讨。     

‘丰香’草莓叶片高效再生体系的建立

 以草莓主栽品种丰香( Fragaria ×ananassa Duch ‘Toyonoka’) 叶片为外植体, 研究了影响组织培养的多个因素, 建立了高效再生体系。结果表明: MS + TDZ 1.5 mg·L ^{- 1} + IBA 0.4 mg·L ^{- 1}培养基最适于不定芽分化。不同滤光膜(绿膜、红膜、蓝膜、黄膜) 对草莓不定芽的分化具显著效应, 绿膜和红膜对芽的分化有明显促进作用, 不定芽再生率达95%以上, 平均每个外植体再生芽数在25个以上; 而蓝膜和黄膜则不利于芽的分化。不同滤光膜光谱差异主要集中在300～700 nm, 红、绿膜在该波段光强较弱,而黄、蓝膜和荧光灯较强。暗处理4周比1、2、3周更有利于提高叶片的不定芽再生率, 此后转到光下培养, 获得的不定芽再生率可达100%。     

香菇烂筒病因与综合防治研究

本文通过对香菇烂筒重灾区进行生态环境、气象、植保等方面调查，应用微生物分离技术，对烂筒样品和土壤样品进行致烂菌的分离、筛选和回接试验，从中确定致烂菌菌株的分类地位和基本生物学特性，从而研制防治香菇烂筒的生态、物理和药物防治技术，提出综合治理措施。     

膜下滴灌量对甜瓜产量和品质的影响

开展不同滴灌量对甜瓜品质影响的研究,对于新疆等西北干旱地区生产优质甜瓜、节约水资源具有重要意义。膜下不同滴灌处理对甜瓜品质的影响研究结果表明:在新疆的气候条件下,田间持水量70%-80%的处理,甜瓜品质表现较好,8601和新密19可溶性固形物含量达到13.69%和16.75%,维生素C含量分别达到8.05、12.55mg/kg,小区产量也分别高于其他处理。     

苹果低氧气调新组合贮后效应的利用研究

利用0.12mm聚乙烯薄膜大帐进行低氧气调新组合的较大规模应用试验,对2394kg玫瑰红苹果进行低氧处理,帐内O2浓度可下调至约2%,CO2浓度可自动维持在5%～8%的较理想状态,处理结束后很易转为MA自发气调。低氧处理后再MA贮藏的苹果,虎皮病果率低、症状轻,腐烂果少,果柄和果皮新鲜,叶绿素保持效果好,果肉硬度明显高于小包装气调和冷藏对照。说明利用塑膜大帐进行前期低氧新组合处理与后期自发气调、实现低氧气调新组合贮后效应的利用是可行的。