A case of giardiasis in a dog in Tasmania - a cause of disease or incidental finding?     

NJ DAVIES  GC HARRISON  JM GOLDSMID 《Australian veterinary journal》1993,70(1):32-33

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Shell strength of eggs from medium‐bodied hybrid hens housed in cages or on range in outside pens     

B. O. Hughes  P. Dun  C. C. McCorquodale 《British poultry science》1985,26(1):129-136

1. On average, over the laying year, a higher proportion of eggs were cracked from cages (4.6%) than from range (2.0%); the difference tended to increase as the flocks aged.

2. There was evidence that eggs from range had stronger shells: they required more energy to crack, shell thickness was greater and shell deformation at 70 weeks was less (though the difference was not significant).

3. The differences between systems in shell strength, although real, were small. It is probable that environmental insults make a much larger contribution than shell strength to differences in crack incidence.

4. Eggs laid by hens on range were larger (+ 6.8% at 36 weeks and + 2.9% at 70 weeks) than those laid by the same stock housed in cages.  相似文献   

石榴果实的糖酸组成及风味特点   总被引：2，自引：0，他引：2  

秦改花  黄文江  赵建荣  邓盾  周玉丽 《热带作物学报》2011,32(11):2148-2151

采用高效液相色谱法测定4种石榴成熟期果实中糖和酸的组成,并对其味感值和糖酸组分与果实风味指标间的相关性进行分析。结果表明,石榴果实中可溶性糖组分有蔗糖、葡萄糖、果糖和山梨醇,其中葡萄糖和果糖含量最高,分别占总糖含量的43.84%~48.36%和49.18%~50.67%。4个品种中,"玉石籽"的总糖含量最高,"白皮"的最低。石榴果实中主要有机酸是奎宁酸、琥珀酸、草酸、L-苹果酸、莽草酸、柠檬酸和D-苹果酸,其中"玛瑙籽"的总酸含量最高,"青皮"的最低。石榴果实中果糖的味感值最大、其次是葡萄糖;味感值最大的酸是奎宁酸,其次为柠檬酸。相关性分析结果表明,石榴果实的糖酸比与甜味/酸味比值之间呈极显著正相关,各品种间糖酸比(甜味/酸味比值)的差异主要取决于有机酸的含量,与糖含量无关。综合其风味特点,"青皮"和"玉石籽"是甜味较浓的品种,"白皮"和"玛瑙籽"则是酸味较浓的品种。  相似文献   

利用CRISPR/Cas9和λ-Red级联技术构建产肠毒素大肠杆菌LT敲除菌株     

檀克勤  马现永  崔艺燕  田志梅  邓盾 《中国畜牧兽医》2020,47(3):666-675

本研究旨在利用CRISPR/Cas9和λ-Red级联的技术对产肠毒素大肠杆菌（enterotoxigenic Escherichia coli，ETEC）K88的热不稳定性肠毒素（heat-labile toxin，LT）基因进行无痕敲除并获得K88 LT^-缺陷菌株。通过序列比对获取LT两端同源序列，并构建包含LT边界、氯霉素筛选标记、sgRNA和LT同源臂的供体片段；将供体片段转化至ETEC K88，同时分别利用λ-Red同源重组系统和CRISPR/Cas9基因编辑系统，对LT基因进行敲除；通过PCR验证获得了K88 LT^-缺陷菌株，并通过试验测定了敲除菌株的溶血能力和生长曲线。结果显示，λ-Red同源重组系统可成功地将LT基因替换为相应的供体片段，CRISPR/Cas9基因编辑系统可高效地对筛选标记进行删除，最终通过λ-Red和CRISPR/Cas9结合的基因编辑系统可成功对ETEC K88的LT基因进行无痕敲除。体外试验结果表明，K88 LT^-缺陷菌株的溶血能力丧失，并且生长速度比野生型菌株减缓，LT可能和ETEC K88的致病能力和生长性能有关。表明λ-Red和CRISPR/Cas9级联的基因敲除方法可用于LT毒素基因及其他一些大肠杆菌基因的敲除。K88 LT^-缺陷菌株的构建为下一步研究LT毒素的致病机制奠定基础。  相似文献   

Design and Experiment of Slave Computer Control System for Applying Variable-rate Liquid Fertilizer     

Zhang Ying-zi  Chen Hai-tao  Hou Shou-yin  Ji Wen-yi  Ouyang Bin-lin  Dun Guo-qiang  Zhang Ji-cheng 《东北农业大学学报(英文版)》2015,(2):73-79

In order to increase the applying rate of liquid fertilizer and reduce environmental pollution, a slave computer control system for applying variable-rate liquid fertilizer was designed. The system used SMC as core processor and electrically controlled pressure regulator as execution component. The characteristic equation of the system was obtained by using classical control theory. Results indicated that the characteristic equation met the requirements of routh-criterion, which indicated the working process of the system was stable. Performance of the slave computer was verified via bench tests. Results demonstrated that there was no significant influence on the response from interclass error. The fertilization error was less than 0.9, and the fertilization accuracy was larger than 97%. The liquid fertilizer emitted by the fertilizing devices had no significant difference in uniformity, which met the demands of the slave computer control system for applying variable-rate liquid fertilizer.  相似文献   

餐厨废弃物饲料化技术及其在动物生产中的应用     

崔艺燕  邓盾  田志梅  鲁慧杰  刘志昌  李家洲  马现永  张琦  兰永辉 《中国畜牧兽医》2021,48(12):4478-4487

餐厨废弃物(food waste,FW)的资源利用受到广泛关注。FW焚化、填埋、堆肥、厌氧消化等技术因其面临的环境可持续性问题而受到越来越多的批评。饲料化技术可以将FW转化为高价值的饲料,从而减少固体废物的排放、养殖成本和环境污染,但该技术应符合减少、再利用和回收有机废物的处理原则。作者综述了FW的饲料化技术及其在动物生产中的应用。FW饲料化技术主要包括热处理、酶处理、藻类培养、昆虫过腹、发酵技术。其中热处理可以确保微生物安全性,是其他技术的预处理技术。藻类培养和昆虫过腹技术可以将FW转化为植物和昆虫蛋白,避免同源污染,但尚不清楚藻类和昆虫在FW利用过程中是否会造成污染物积累。酶处理和发酵技术可以将FW中大分子转化为小分子。酶的催化性能和稳定性容易受外界条件的影响,需要考虑特殊的酶制剂。发酵技术的机械化程度和资源利用率高,其核心是微生物,需要筛选有效的、能充分利用FW的微生物。目前FW在畜牧业中的应用较少,在其生产和应用中要特别注意用量和使用时间。为了使FW饲料真正作为动物饲料进入食物链,研究人员必须对不同动物(含不同生长阶段)的生长性能和产品特性进行研究,以确保动物健康及动物产品对人类健康没有负面影响。  相似文献   

Policies for the vaccination of cats and dogs in New Zealand veterinary practices     

NJ Cave  R Jackson  JP Bridges 《New Zealand veterinary journal》2016,64(3):145-153

AIMS: To determine current practices and attitudes towards vaccination of dogs and cats of veterinarians in New Zealand; the methods used for informing clients on which vaccines to use, and the preferred site for vaccination of cats.

METHODS: A postal questionnaire was sent to all 483 listed veterinary practices in New Zealand during February 2012. Some questions were specific to pet dogs, cats, or working farm dogs. Responses were categorised according to practice type and geographical region of the respondent. Factors associated with respondent recommendation of annual vaccination with modified live viral (MLV) vaccines were examined using logistic regression analysis. Vaccines that were considered to be essential for every animal were defined as core; those that may be recommended for animals whose location or lifestyle placed them at risk, were defined as non-core.

RESULTS: There were 204 useable returns, equivalent to a response rate of 42.2%, distributed across the country. Annual vaccination with MLV vaccines of dogs was recommended by 54/198 (27.3%) respondents, and of cats by 107/181 (59.1%) respondents. Factors associated with the recommendation of annual administration of MLV vaccines to dogs included being a companion animal practice, a desire for policies on vaccination to be left to individual clinics, and having one veterinarian in the practice. Administration of the final vaccination for puppies was recommended at ≥14 weeks old by 55/185 (29.7%) respondents, and for kittens at ≥13 weeks old by 42/183 (23%) respondents. Of respondents that administered MLV vaccines annually, 62/103 (60.2%) believed reducing the frequency of vaccination would reduce income, and 52/103 (50.5%) considered it would have a negative effect on animal health. Advice to enable clients to decide which non-core vaccines were administered was given by 181/199 (91%) respondents. Factors considered when recommending a vaccine included consideration of risk to individual patients (190/203; 93.6%), requirements of boarding kennels/catteries (165/203; 81.3%) and clinic vaccination policy (142/203; 70%). The preferred site for administering MLV vaccines to cats was the dorsal neck or inter-scapular region (137/198; 69.2%). Amongst respondents, 18 wanted disease surveillance information to allow for truly informed decisions to be made about vaccination.

CONCLUSIONS AND CLINICAL RELEVANCE: Veterinarians can now compare their own vaccination practices and attitudes with those of veterinarians nationally, and internationally. There is a need for national surveillance information and for continued education of the public and commercial kennel and cattery owners for optimal vaccination strategies to be developed.  相似文献   

水稻插秧机植物纤维地膜敷设装置开口机构设计   总被引：1，自引：0，他引：1  

张子浩  陈海涛  顿国强  赵阳  王业成  纪文义 《农机化研究》2015,(3):79-82

针对自制的水稻插秧机植物纤维地膜敷设装置由秧爪直接进行开口插秧、而导致开口质量较差的问题,利用ADAMS建立了偏心齿轮式分插机构的运动仿真模型,通过轨迹跟踪及逐次逼近的方法确定了开口刀尖点的最优坐标为(-159.8,54.9)。依此建立双臂同步开口机构仿真模型并对开口插秧过程进行了仿真模拟,结果表明机构满足设计要求。最后,对同步开口机构开口刀的装配结构进行了优化设计。  相似文献   

天河公园“拆围透绿”工程边界空间绿化模式研究   总被引：1，自引：1，他引：0       下载免费PDF全文

方永红  王盾＊ 《广东园林》2023,(1):70-73

边界空间绿化是开放性城市公园的重要因素,是衔接公园与城市绿地系统的重要措施。以广州天河公园“拆围透绿”工程为例,分析边界空间绿化存在通透性不足、与城市融合度不高、地域文化缺失、绿地管理不到位等问题,采用“保留、清杂、复绿”景观策略,确定点状、带状、片状景观3种绿化模式,制定“护栏+绿化”、绿化组团、“微地形+绿化组团”3种空间分隔手法,并从复绿植物种类选择、通透植物空间结构、活化林下消极空间、柔化公园边界空间、强化城市地域文化、加强空间绿化管理6个方面进行绿化提升,优化了公园的生态环境和开放性。  相似文献   

用茉莉酸甲酯局部喷施长白落叶松苗对落叶松毛虫体内防御酶的影响   总被引：1，自引：1，他引：0  

姜礅  孟昭军  严善春 《北京林业大学学报》2017,39(2):58-63

为明确茉莉酸甲酯局部处理林木对落叶松毛虫解毒代谢的影响，本研究以3种不同浓度的茉莉酸甲酯(MeJA，0.01、0.10和1.00mmol/L)局部处理长白落叶松苗的侧枝，分析不同处理对取食其针叶的落叶松毛虫3~5龄幼虫体内保护酶和解毒酶活性的影响。研究发现，3个浓度的MeJA局部处理长白落叶松对松毛虫幼虫体内保护酶和解毒酶活性均有显著影响(P < 0.05)，酶活变化趋势一致，但未呈浓度依赖关系。各处理组幼虫体内的SOD和POD活性均在第4龄显著高于CK(P < 0.05)，但3、5龄幼虫体内的SOD和POD活性与CK差异不显著(P>0.05)；而ACP、AKP和GSTs活性先在第3龄低于CK、第4龄均显著低于CK(P < 0.05)，后在第5龄不同程度地高于CK。表明用MeJA局部喷施能诱导提高长白落叶松的系统抗性，且其对食叶害虫具有广谱性，能干扰落叶松毛虫的解毒代谢，抵御其危害；落叶松毛虫能在逐渐适应后，通过提高保护酶和解毒酶的活性去响应诱导抗性造成的毒害。   相似文献