Obtaining Wisent early blastocyst in vitro is a basic for protection and creation of biodiversity for this threatened species

Wisent, or European bison (Bison bonasus), is listed as “vulnerable” on the IUCN Red List of Threatened Species and is therefore protected by international law. For the first time, a Wisent embryo has been obtained in vitro. This procedure creates a new opportunity to protect and increase Wisent reproductive potential and thereby opens new possibilities for the establishment of a controlled and broad reserve of the gene pool.     

白头翁汤和黄连解毒汤对鸡大肠杆菌病的治疗作用

研究中药经方白头翁汤和黄连解毒汤对鸡大肠杆菌病的治疗作用。采用体外抗菌和人工感染防治试验相结合的方法,测定了2个经方对临床分离的大肠杆菌多重耐药菌株的最低抑菌浓度(MIC)和对人工感染鸡大肠杆菌病的防治效果。结果显示,这2个经方体外对大肠杆菌均有抑菌效果,黄连解毒汤对试验菌株的MIC平均值为0.250 g/mL,而白头翁汤对试验菌株的MIC平均值为0.187 g/mL,效果较优;人工感染防治试验结果显示黄连解毒汤对鸡大肠杆菌病的保护率、有效率和治愈率均高于白头翁汤,尤其是高剂量组防治效果最好,保护率和有效率均达90%,治愈率达85%。说明2个经方在体内外抗菌试验中均有效果,但是体内、外抗菌效果不一致。     

氯消毒剂对鸡生产性能的影响及致病作用

在饮水中添加1％、2％、25％的含氯消毒剂，对土杂鸡进行了为期21d的中毒试验。鸡每天每1kg体重摄入0．543、0．768、0．288g的含氯消毒剂后，鸡群的饮水、摄食、生长速度与对照组比较都有不同程度的减少，且随试验时间的延长而加剧，生长速度分别降低32．06％、93．7％、124．4％，饲料报酬分别降低35．3％、78．53％和呈负比率，并在后期出现不同程度的临床表现和死亡，表明鸡连续大量摄入含氯消毒剂可在体内蓄积并引起机体慢性中毒。     

Genetic diversity of mtDNA D-loop sequences in four native Chinese chicken breeds

1. To explore the genetic diversity of Chinese indigenous chicken breeds, a 585 bp fragment of the mitochondrial DNA (mtDNA) region was sequenced in 102 birds from the Xichuan black-bone chicken, Yunyang black-bone chicken and Lushi chicken. In addition, 30 mtDNA D-loop sequences of Silkie fowls were downloaded from NCBI. The mtDNA D-loop sequence polymorphism and maternal origin of 4 chicken breeds were analysed in this study.

2. The results showed that a total of 33 mutation sites and 28 haplotypes were detected in the 4 chicken breeds. The haplotype diversity and nucleotide diversity of these 4 native breeds were 0.916 ± 0.014 and 0.012 ± 0.002, respectively. Three clusters were formed in 4 Chinese native chickens and 12 reference breeds. Both the Xichuan black-bone chicken and Yunyang black-bone chicken were grouped into one cluster. Four haplogroups (A, B, C and E) emerged in the median-joining network in these breeds.

3. It was concluded that these 4 Chinese chicken breeds had high genetic diversity. The phylogenetic tree and median network profiles showed that Chinese native chickens and its neighbouring countries had at least two maternal origins, one from Yunnan, China and another from Southeast Asia or its surrounding area.     

复方中药对感染NIB鸡红细胞免疫功能的影响

为了探明由熟地等组成的复方中药对人工感染NIB雏鸡红细胞免疫功能的影响规律,将雏鸡随机分为5组（空白对照组,攻毒对照组,复方中药低剂量、中剂量、高剂量治疗组）,分别于给药后3、6、9、14、19 d采集血样,测定RBC-CR1花环率与RBC-IC花环率。结果显示,该复方中药可以使人工感染NIB雏鸡RBC-CR1花环率显著回升,并恢复到正常水平;同时使人工感染NIB雏鸡RBC-IC花环率显著升高,然后再恢复到正常水平。该复方中药的作用呈现剂量效应。该复方中药可以提高人工感染NIB雏鸡红细胞的免疫功能。     

肉仔鸡腹腔注射心律平急性毒性试验

21日龄AA 肉仔鸡雌雄各半共110只,分为预试验组,试验组和对照组。按预试验得出的最大有效量、最高致死量和公比确定各试验组剂量腹腔注射心律平,对照组注射生理盐水。结果对照组无死亡,试验组死亡数随剂量加大而增加。试验得出心律平最大有效量为28.56mg/kg,最高致死量为59.22mg/kg,半数致死量(LD50)为41.88mg/kg。中毒鸡表现神经症状和呼吸困难,剖检见肝、肾肿大,心、肺出血等变化。     

添加鱼油在肉仔鸡饲料中的应用研究

选择40日龄土杂肉仔鸡450只进行为期3周的实验。研究了鱼油在肉仔鸡饲养中的应用效果。结果表明:使用鱼油,对鸡的免疫力无影响,但对肉鸡的生长速度、饲料报酬、肉的品质和经济效益均有明显的提高作用。肉仔鸡日粮中添加2%鱼油效果优于添加3%。     

狗枣猕猴桃叶片离体培养的器官、体细胞胚形成与植株再生(英文)

以狗枣猕猴桃试管苗的叶片为外植体,接种于含3%蔗糖和0.2%Gelrite的BW培养基上,外加2,4-D(0,0.1,1和10μmol/L)与玉米素(0,1和10μmol/L)的12种激素组合,置于25℃,光周期为16/8h,光照强度为4000lx的条件下培养。在含1或10μmol/L2,4-D与1或10μmol/L玉米素组合的BW培养基上,产生了体细胞胚,并分化出小植株。随着玉米素浓度的增加,每个外植体上的胚再生频率和体细胞胚的数量也随之增加。同时以叶片为外植体产生的狗枣猕猴桃试管苗的愈伤组织表层产生了不定芽,并抽长成枝。发枝率随着玉米素浓度的增加而增加,并受高浓度的2,4-D所抑制。枝芽转接到含1μmol/LNAA的BW培养基上生根,长成小植株。     

单诺沙星对人工诱发鸡大肠肝菌病的药效试验

根据试管 2倍稀释法测定的单诺沙星及氯霉素对鸡大肠杆菌的最小抑菌浓度 ,对实验性大肠杆菌病鸡进行内服给药 (每隔 12h给药 1次 ,连续 3d)治疗试验。结果表明 ,单诺沙星及氯霉素对鸡大肠杆菌的最小抑菌浓度分别是 0 0 5及 1 6mg/L。单诺沙星以 5mg/kg、氯霉素以40mg/kg的剂量给鸡内服后 ,对大肠杆菌病的治愈率分别为 87 5%及 55 0 %。     

氟对鸡甲状腺中碘代谢的影响

为探讨氟对鸡甲状腺中碘代谢的影响，选用250只1日龄蛋鸡，随机分为5组，每组50只，饲喂相同的全价日粮。第Ⅰ组：正常对照组，Ⅱ，Ⅲ，Ⅳ，Ⅴ组在日粮中添加不同水平的氟化钠，使日粮中氟的含量分别为500，1000，1500和2000mg/kg，试验期为150d，每隔30d采集血样，测定血清中氟含量、甲状腺中碘含量，观察试验鸡的临床表现。成功地复制出不同程度的鸡慢性氟中毒模型，试验鸡日粮含碘量正常。结果表明各中毒组甲状腺中碘含量在整个试验期内均不同程度地低于对照组，呈明显的剂量－效应和时间－效应关系。甲状腺中碘含量变化和相应时期的血清氟含量间呈显著的负相关（r=-0.814)。说明氟能明显地抑制甲状腺摄取和聚集碘的能力，干扰碘的正常代谢，进而影响整个甲状腺的结构和功能。