谷氨酰胺对肉仔鸡生长性能和盲肠沙门氏菌定植的影响

文章旨在研究谷氨酰胺对肉鸡生长性能和盲肠沙门氏菌水平的影响。试验1选择1日龄AA肉仔鸡234只,随机分为3组,每组3个重复,每个重复26只鸡,对照组饲喂玉米-豆粕型日粮,处理1组饲喂基础日粮(在3日龄感染3.6×10^6cfu沙门氏菌),处理2组饲喂基础日粮+10g/kg谷氨酰胺(在3日龄感染3.6×10^6cfu沙门氏菌)。试验2选择1日龄AA肉仔鸡312只,随机分为4组,每组3个重复,每个重复26只鸡,对照组和处理1组同试验1,处理3组同试验1的处理2组,但肉鸡感染7.5×10^6cfu沙门氏菌试验2处理2组饲喂基础日粮+10g/kg谷氨酰胺(不感染沙门氏菌)。两个试验均开展14d。试验1:日粮添加谷氨酰胺对肉鸡生长性能无显著影响(P>0.05)。试验2:处理2组较其他组显著提高了1~7d肉鸡的体重和日增重(P<0.05)。肉鸡感染沙门氏菌4或10d后,日粮添加谷氨酰胺对盲肠沙门氏菌含量无显著影响(P>0.05)。结论:日粮添加1%谷氨酰胺可以提高肉鸡生长性能,但并没有降低盲肠沙门氏菌水平,这说明日粮中添加1%谷氨酰胺不足以达到降低盲肠沙门氏菌的最佳水平。     

流感病毒气源性传播研究进展

流感病毒是现今世界流行最为广泛、传播最为迅速的人兽共患病毒之一,而气源性传播是流感病毒最有效的传播方式.流感病毒的相关基因,尤其是相关基因的关键氨基酸位点对其自身是否具有气源性传播能力具有决定性的作用.外界环境的改变会直接影响病毒气溶胶颗粒形成的数量和大小,进而影响传播效率.目前,经过长期的筛选和比较,将豚鼠和雪貂作为研究流感气源性传播的模式动物,根据不同目的或者单独使用或者协同实验.文章通过对病毒本身的生物学特性以及外界环境对气源性传播产生的影响进行了初步总结,对进行气源性传播的实验动物给出了综合评价,一方面为研究者提供较为全面的总结,另一方面为防治流感提供依据.     

Isolation,Identification and Analysis of Serotype and Antibiotic Susceptibility of Pathogenic Salmonella from Chickens

To investigate the situations of predominant strain and antibiotic resistance of pathogenic Salmonella from chickens in Guangxi Zhuang Autonomous region, Salmonella was pre-enriched and isolated from tissues of clinical suspected chickens, and the Salmonella isolates were identified by biochemical test using ID 32E System for the identification of Enterobacteriaceae of VITEK System ATB Expression, serotypes were determined by slid agglutination test, antibiotic susceptibility was analyzed by ATB VET Susceptibility Test Strip of Enterobacteriaceae antibiotics.The results showed that 34 Salmonella strains were obtained from 310 clinical samples, of which 1 strain belonged to A serogroup, 1 to C2 serogroup, 15 to B serogroup, 14 to D serogroup and 3 to untyped serogroup, and S.typhimurium of B serogroup and S.pullorum of D serogroup were the predominant serotypes.All Salmonella isolates were sensitive to meropenem, imipenem, spectinomycine and apramycine, and the resistance rates to chloramphenicol, kanamycine and gentamicine were less than 10%, and the resistance rates to amoxicillin, streptomycine, flumequine, oxolinique, sulfamethizol, tetracycline and nitrofurantoine ranged between 50% and 90%, while the resistance rates to penicilline, oxacilline, fusidique, rifampicine and metronidazole reached to 100%.The results indicated that the serotype distribution of pathogenic Salmonella from chickens exhibited regional characteristics, and S.typhimurium and S.pullorum were the predominant serotypes in Guangxi Zhuang Autonomous region, and antibiotic resistance of Salmonella isolates was very serious which should be highly concerned.     

单诺沙星在雏鸡体内的药动学特征及生物利用度研究

以高效液相色谱法为定量手段研究了单诺沙星内服给药在雏鸡体内的药动学特征及生物利用度。 12 0只雏鸡静注或内服单诺沙星 (5mg/kg)后 ,血药浓度时间数据分别符合无吸收二室模型和一级吸收二室模型。静注给药的主要动力学参数为t1/ 2α0 .34h ,t1/ 2 β为 7.3184h ,VB 为 16 .0 6 31L/kg ,AUC为 3.2 872mg/L·h ,Tcp为 2 5 .0 1h。内服给药的主要动力学参数如下 :t1/ 2ka为 0 .2 42 8h ,t1/ 2α为 0 .8917h ,t1/ 2 β为 8.7936h ,Tp 为 0 .9377h ,Cmax为 0 .5 487μg/mL ,AUC为3 .0 5 2 3mg/L·h ,Tcp为 31.115h。内服生物利用度为 92 .85 %。     

柔嫩艾美耳球虫感染对肉仔鸡粪便水分的影响

采用单因子试验设计法,测定肉仔鸡感染柔嫩艾美耳球虫(E.tenella)后对粪便中水分变化的影响。试验表明:感染柔嫩艾美耳球虫后,鸡的生产性能受到显著的影响(P<0.05)。粪便中水分含量高于未感染组,感染后4d粪便中水分含量呈上升趋势,研究认为,粪便中水分含量的增加是球虫感染后的鸡的病理性变化的一种生理反映。在临床上,可将鸡粪便中水分含量的变化作为评判鸡感染球虫的参考指标之一。     

鳜塘水体理化因子昼夜变化及相关性研究

通过对鳜塘水体部分理化因子昼夜检测及藻类的观察 ,分析了塘水重要理化因子昼夜变化情况。结果表明 ,不同鳜塘溶氧、pH值昼夜升降变化规律基本一致 ,总铵、亚硝酸盐氮、磷酸盐磷昼夜变化因塘而异。鳜塘生态因子的统计分析还显示 ,磷酸盐磷与异氧细菌数 (r2 8=0 30 )相关性最大 ,其次是与溶氧 (r2 8=0 2 4 ) ;亚硝酸盐氮与叶绿素a呈负相关 (r2 8=- 0 35) ;总铵与多数因子呈负相关 ,但相关不显著     

香根草根际AM菌的感染特性

通过对不同种植时间、不同种植基质的香根草Vetiveria zizanioides分株苗、组培苗根际丛枝菌根(AM菌)感染检测,探讨了香根草对AM菌的感染特性.结果表明,在消过毒的森林泥炭土中,组培苗种植12个月感染率只有20.0%,感染强度低;种植22个月只有53.3%,感染强度为中.分株苗种植在自然土壤中,3个月就有AM菌感染,其感染率为56.7%;种植22个月感染率达到最高峰,为80.0%,感染强度为中等;种植时间为33个月时,感染率不再增加,但感染强度进一步增高.说明香根草根际AM菌的感染率和感染强度可能与苗源无关,而与种植基质密切相关.     

18S rRNA／rDNA序列分析技术在瘤胃原虫分类学研究中的应用

作者指出了反刍动物瘤胃原虫分类学研究中的难点，介绍了原虫分类学中新兴的分子生物学指标(18S rRNA／rDNA序列同源性)，综述了18S rRNA／rDNA序列分析技术在瘤胃原虫分类研究中的应用。     

In vitro effect of levamisole on the cell viability,phagocytosis and respiratory burst of Barbel chub (Squaliobarbus curriculus) macrophages

The present study was to determine in vitro effect of levamisole on the immune functions of Barbel chub (Squaliobarbus curriculus), head–kidney‐derived (HKM), spleen‐derived (SM) and peripheral blood monocyte‐derived macrophage (PBM). Macrophages were incubated with levamisole 10³, 10¹, 10⁻¹ and 10⁻³ ng mL⁻¹ to assay the cell viability, respiratory burst and phagocytosis. The results showed that macrophages treated with levamisole 10⁻³ ng mL⁻¹ gave a maximum respiratory burst response, whereas levamisole 10³ ng mL⁻¹ had no effect. Phagocytosis activity of the macrophages treated with levamisole enhanced significantly when compared to control, maximum response being at 10⁻³ ng mL⁻¹. While using the methylthiazoletetrazolium method to measure the cell activity for 12, 24, 36, 48, 60 h, there was no significant role on proliferation and the cell viability began to decline after 24 h. In conclusion, levamisole is a potent enhancer of Barbel chub macrophage activity with low concentration.     

紫花苜蓿不同基肥配比效应的研究

针对云南紫花苜蓿Medicago sativa种植缺乏专用肥的研究,采用"3414"的试验设计来研究不同基肥配比对紫花苜蓿第1年产量、株高、叶茎比、单株质量的影响.试验得出,施N 57.3 kg/hm2、P2O5 138 kg/hm2、K2O 36.45 kg/hm2时年产最高,达104 865 kg/hm2;施N 129.3 kg/hm2、P2O5 -5.1 kg/hm2(视为不施磷肥)、K2O 82.5 kg/hm2时茎叶比最大,达52.12%;施N 79.35 kg/hm2、P2O5 73.05 kg/hm2、K2O 106.05 kg/hm2时株高最大,达61.56 cm;施N 24.9 kg/hm2、P2O5 79.05 kg/hm2、K2O 80.1 kg/hm2时单株质量最高,达5.58 g.