高效液相色谱法检测泰乐菌素在肉鸡组织中的残留

将肉鸡的肌肉、肝脏、肾脏和脂肪组织制成匀浆,用乙腈、石油醚和二氯甲烷萃取、净化后,用乙腈定容。以乙腈－ 甲醇－ ０．００５ ｍ ｏｌ／ Ｌ磷酸二氢铵溶液（６０∶３０∶１０）为流动相,用高效液相色谱检测。本法对溶解于乙腈中的泰乐菌素的最低检测限为 ０．０５ ｍ ｇ／ Ｌ,在肉鸡各种组织中的最低检测限为 ０．１０ ｍ ｇ／ Ｌ。标准曲线的线性范围为 ０．１０～６．４０ ｍ ｇ／ Ｌ。泰乐菌素质量浓度为 ０．１０、０．８０、６．４０ ｍ ｇ／ Ｌ 时的批间变异系数分别为（２．３±０．２）％ 、（１．９±１．３）％ 、（２．６±０．９）％ 。０．２０、０．４０、０．８０ ｍ ｇ／ Ｌ 的泰乐菌素在以上 ４ 种组织的回收率均符合残留检测的要求。结果表明,本法是一种灵敏、精密、可靠的检测肉鸡组织中泰乐菌素残留的分析方法。     

鹦鹉热衣原体荧光环介导等温扩增（LAMP）检测方法的建立

鹦鹉热衣原体(Chlamydia psittaci)是一种人兽共患病原体,能引起自然疫源性衣原体病,目前广泛分布于世界各地。本研究应用环介导等温扩增技术(LAMP),针对鹦鹉热衣原体23S RNA基因序列设计引物,并进行筛选以及敏感性和特异性试验,建立了鹦鹉热衣原体恒温荧光扩增方法。该方法在63℃恒温条件下1 h内即可显示结果,操作简单、快速,特异性强,灵敏度可达100拷贝/μL,且与流产衣原体、动物布鲁氏菌、牛结核分枝杆菌、沙门氏菌、大肠杆菌、金黄色葡萄球菌无交叉反应;用国产仪器可直接通过检测荧光信号判读结果,既增强了准确性,也避免了开盖污染产生假阳性;应用建立的LAMP方法对实验室保存的临床DNA样品进行检测,发现检测结果与QPCR相同。该方法的建立弥补了传统检测技术的不足,为实现鹦鹉热衣原体的现场快速诊断提供了技术支持。     

Analysis of Rumen Microbial Diversity and Functional Prediction of Chinese Simmental Cattle Based on 16S rRNA High-throughput Sequencing Technology

To systematically explore the microbial diversity and function in the rumen of Chinese Simmental cattle,this experiment used 16S rRNA gene high-throughput sequencing technology to detect and analyze the rumen fluid samples of Simmental cattle (about 20 months old,the average weight was 550 kg),and its function was predicted by PICRUSt.The results showed that a total of 66 712 high-quality sequences were obtained from the Illumina Miseq sequencing platform,and 1 797 operational classification units (OTU) were obtained by cluster analysis.The taxonomic identification was divided into 13 phylums,20 classes,22 orders,33 families and 59 genuses;Firmicutes and Bacteroidetes were dominant bacteria,accounting for 62.46% and 22.45%,respectively;Based on the genus composition,[Eubacterium]_coprostanoligenes_group (9.16%),Ruminococcus_2 (7.90%),norank_f__Bacteroidales_RF16_group(6.23%),norank_f__Ruminococcaceae(4.79%),Rikenellaceae_RC9_gut_group(4.72%),norank_f_Bacteroidales_BS11_gut_group(4.49%),Ruminococcus_1(4.43%),etc.The PICRUSt function of the 16S rRNA genome predicted that the rumen flora function was mainly concentrated in carbohydrate transport and metabolism,and might contain a large amount of cellulose and lignin degrading enzyme genes.In summary,the high-throughput sequencing technology based on 16S rRNA gene fully revealed the diversity of rumen bacteria in Simmental cattle,and predicted that it was rich in protein decomposition and lignocellulose degrading enzymes.The basis of microbial cognition provided a reference for further research on rumen microbial functional genes closely related to some important nutritional and physiological functions.     

Effects of Wnt10b on dermal papilla cells via the canonical Wnt/β‐catenin signalling pathway in the Angora rabbit

Wnt10b is a member of Wnt family that plays a variety of roles in biological functions, including those in the development of hair follicles. To investigate the effect of Wnt10b on hair growth in the Angora rabbit and to determine the underlying molecular mechanism, we cultured dermal papilla (DP) cells with exogenous Wnt10b in vitro. We observed the expressions of downstream critical gene β‐catenin and lymphoid enhancer‐binding factor 1 (LEF1) in Wnt/β‐catenin pathway. The levels of β‐catenin mRNA and protein were higher in the Wnt10b group of DP cells than in the Control group, and the mRNA level of LEF1 in the Wnt10b group was higher than in the Control group. Moreover, translocation of β‐catenin from cytoplasm to nucleus was activated in the Wnt10b group. Furthermore, the mRNA levels of the hair follicle‐regulatory genes, insulin‐like growth factor‐1 (IGF‐1) and alkaline phosphatase (ALP), and the protein activity of ALP was also upregulated in the Wnt10b group compared to their corresponding levels in the Control group. These data suggest that Wnt10b could activate the canonical Wnt/β‐catenin signalling pathway to induce DP cells in the Angora rabbit. In addition, the proliferation of DP cells was significantly promoted when cultured with Wnt10b for 48 and 72 hr, suggesting that Wnt10b plays a pivotal role in the proliferation and maintenance of DP cells in vitro. In conclusion, this study demonstrates that Wnt10b may promote hair follicle growth in Angora rabbit through the canonical Wnt/β‐catenin signalling pathway that promotes the proliferation of DP cells.     

Pharmacokinetics of sanguinarine,chelerythrine, and their metabolites in broiler chickens following oral and intravenous administration

Sanguinarine (SA) and chelerythrine (CHE) are the main active components of the phytogenic livestock feed additive, Sangrovit®. However, little information is available on the pharmacokinetics of Sangrovit® in poultry. The goal of this work was to study the pharmacokinetics of SA, CHE, and their metabolites, dihydrosanguinarine (DHSA) and dihydrochelerythrine (DHCHE), in 10 healthy female broiler chickens following oral (p.o.) administration of Sangrovit® and intravenous (i.v.) administration of a mixture of SA and CHE. The plasma samples were processed using two different simple protein precipitation methods because the parent drugs and metabolites are stable under different pH conditions. The absorption and metabolism of SA following p.o. administration were fast, with half‐life (t_1/2) values of 1.05 ± 0.18 hr and 0.83 ± 0.10 hr for SA and DHSA, respectively. The maximum concentration (C_max) of DHSA (2.49 ± 1.4 μg/L) was higher that of SA (1.89 ± 0.8 μg/L). The area under the concentration vs. time curve (AUC) values for SA and DHSA were 9.92 ± 5.4 and 6.08 ± 3.49 ng/ml hr, respectively. Following i.v. administration, the clearance (CL) of SA was 6.79 ± 0.63 (L·h^?1·kg^?1) with a t_1/2 of 0.34 ± 0.13 hr. The AUC values for DHSA and DHCHE were 7.48 ± 1.05 and 0.52 ± 0.09 (ng/ml hr), respectively. These data suggested that Sangrovit® had low absorption and bioavailability in broiler chickens. The work reported here provides useful information on the pharmacokinetic behavior of Sangrovit® after p.o. and i.v. administration in broiler chickens, which is important for the evaluation of its use in poultry.     

兔绿脓假单胞菌性肺炎的诊断与防治

本文报道近年来我省某试验养兔场兔群中流行一种生前以呼吸困难、口鼻出现血样分泌物症状,死后剖检以肺组织变性坏死为特征的疫情,经临床观察、实验诊断、病理剖检和病理组织学检查、流行病学调查及动物致病性实验研究,鉴定为绿脓假单胞菌(Ps.aeruginosa)引起的肺炎,该病特点传染快、死亡率高。通过流行病学调查,探索该病发病流行规律,为防治本病提供科学依据。     

氟化物对鸡甲状腺激素代谢的影响

选用 1日龄蛋鸡 2 5 0只 ,随机分为 5组 ,每组 5 0只 ,饲喂相同的全价日粮。第 1组为正常对照组 ;第 2、3、4、5组在日粮中添加不同量的氟化钠 ,使日粮中氟的含量分别为 5 0 0、10 0 0、15 0 0、2 0 0 0 m g/ kg。试验期 15 0 d。每隔 30 d采集血样 ,测定血清中氟、甲状腺激素 (T3、T4 )的含量 ,观察试验鸡的临床表现。结果表明 ,本试验成功地复制出了不同程度的鸡慢性氟中毒模型 ;各氟中毒组鸡血清中 T4 含量在整个试验期内均低于对照组 ,且呈明显的剂量—效应关系 ;在早期 ,各中毒组血清 T3含量不同程度地高于对照组 ,而中、后期则低于对照组 ,且与血清中氟含量呈显著的负相关(r=- 0 .85 3,P<0 .0 1)。由此可见 ,氟中毒明显破坏机体内甲状腺激素的代谢 ,影响甲状腺机能的正常发挥。     

返滴定法测定蜂胶中游离酸含量

建立测定蜂胶品中游离酸含量的方法.采用弱碱溶解蜂胶再酸化萃取的方法纯化样品,用返滴法测定,以水杨酸作为对照品检测样品中游离酸含量.结果测定了5个不同产地的蜂胶样品,游离酸含量在1.89～6.54%范围内,回收率为99.30%.本方法操作简单,重现性好,有助于蜂胶质量的鉴别.     

不同遮荫强度对草地早熟禾草坪质量的影响

为研究不同遮荫强度对新建草地早熟禾(Poa pratensis)草坪生长状况的影响,于2009年5月1日-11月6日进行试验,共设计自然光照、轻度遮荫、中度遮荫和重度遮荫4种不同遮荫强度,对干旱胁迫下草地早熟禾的生长速率、草坪质量、草屑重量、叶色值、电导率和地下生物量等形态指标和生理指标进行观察测定。结果表明,在少雨时节中度遮荫的草坪质量较高,多雨时节则轻度遮荫的草坪质量较好;适度遮荫下草坪草的生长正常,叶色较好,电导率较小,草坪质量较高。因此,可以利用适度遮荫,减少夏季高温与干旱对草地早熟禾草坪的伤害,改善草坪质量。     

规模养猪引起环境污染的防制对策

规模养猪场对外界环境污染物主要是粪尿污物及其产生的有害气体,为减少它们对周围环境的水、土壤、空气造成污染的程度,避免成为畜禽传染病、寄生虫病和人畜共患疾病的传染源,养猪场应采取一切行之有效的措施,加强和实施对生产污物的治理措施,在提高产量的同时,注重对环境的保护,减轻畜牧业生产活动对环境的危害,以促进养猪业经济效益、社会效益、生态效益的协调发展。