鸡毒支原体SC克隆致弱株免疫原性测试——开放动物模型的建立与应用

对罗斯鸡和 Ｓ Ｐ Ｆ来航鸡用鸡毒支原体强毒攻击时,以鸡致病性大肠杆菌 Ｏ７ ８ 血清型菌株 １６ 小时培养物 ０２ｍ ｌ／羽皮下注射作人工诱导发病,试验鸡出现明显气囊病变,初步建立了以鸡致病性大肠杆菌为诱导因子的 Ｍ Ｇ 野外环境人工发病的动物模型。以此开放模型检测 Ｓ Ｐ Ｆ来航鸡以鸡毒支原体 Ｓ６ 克隆致弱株 Ｆ１５６ 代培养物点眼、滴鼻免疫后 ３０ 日、６０ 日龄的攻毒保护率,结果保护率分别达 ９０％ （１８／２０）、８４％ （４２／５０）,而对照组为 ３０％ （６／２０）、５０％ （１５／３０）,中期免疫效果证明,鸡毒支原体 Ｓ６ 克隆致弱株有良好的免疫保护作用。     

鸡传染性腔上囊病超强毒致弱株疫苗的研制

以国内分离的鸡传染性腔上囊超强毒（ｖｖＩＢＤＶ）Ｇ株的致弱株Ｇｔ为种毒研制疫苗,实验室免疫效力试验和安全性试验表明,该疫苗对雏鸡的最适免疫剂量为５０万ＰＦＵ／只,免疫后７ｄ开始产生抗体,１４ｄ时抗体阳转率为１００％,对强毒攻击的保护率为１００％：以５００万ＰＦＵ／只的剂量免疫雏鸡,不引起腔上囊病的临床症状和病理变化,对雏鸡安全可靠;现地应用证明,对肉用鸡免疫一次或保护至其出栏。     

鸡传染性鼻炎多价油乳剂灭活苗的免疫对比及田间试验

从山东省分离了６株鸡传染性鼻炎菌株,经过抗原比较,攻毒交叉保护试验,发现ＨＰＧ－ＨＺ株的保护性最佳,利用ＨＰＧ－ＨＺ株与标准Ａ型菌株ＨＰＧ－００８３株和标准Ｃ型菌株ＨＰＧ－Ｍｏｄｅｓｔｏ株结合,成功研制了鸡传染性鼻炎多价油乳剂灭活苗。将该疫苗在山东省、河北省、河南省等地共４５００万只鸡进行田间免疫试验和与同类疫苗的对比试验,结果表明,鸡传染性鼻炎多价油乳剂灭活苗对鸡群安全、有效,无副作用,免疫期可达６个月以上。特别对山东分离株的免疫保护比进口和国产同类疫苗均有优势。     

蛋鸡鸡毒支原体与大肠杆菌混合感染的诊断及对产蛋率影响的分析

对湖北省某鸡场１１０只蛋进行了鸡毒支原体（ＭＧ）、滑液支原体（ＭＳ）血清平板凝集试验（ＳＰＡ）具有明显临床症状的鸡（眶下窦炎，呼吸困难，罗音等）均为ＭＧ－ＳＰＡ阳性（５４／５４）同舍６０只无症状鸡中有４６只为ＭＧ－ＳＰＡ阳性（７６．６％）对４只病鸡及４只ＭＧ－ＳＰＡ阴性健康鸡进行了支原体及细菌的分离鉴定。结果从３只病鸡中分离到鸡毒支原体，从２只病鸡分离到大肠杆菌Ｏ２血清型，证明为鸡毒支原体与大肠杆     

鸡传染性支气管炎病毒S1基因免疫对鸡的保护作用

将鸡传染性支气管炎病毒肾型 Ｔ 株 Ｓ１ 基因ｃ Ｄ Ｎ Ａ 连接于ｐｃ Ｄ Ｎ Ａ３ 的 Ｈｉｎｄ Ｉ Ｉ Ｉ与 Ｂａ ｍ Ｈ Ｉ位点之间构建含有 Ｃ Ｍ Ｖ 启动子及 Ｂ Ｇ Ｈｐｏｌｙ Ａ 信号序列的鸡传染性支气管炎病毒 Ｓ１ 蛋白真核表达质粒。实验证明, Ｓ Ｐ Ｆ 鸡肌注免疫后血清 Ｉｇ Ｇ 抗体逐渐升高,至第３５ 日龄左右达到高峰,攻毒后血清 Ｉｇ Ｇ 抗体先下降而后升高,血清 Ｉｇ Ｇ 抗体升高幅度不及 Ｉ Ｂ 油苗免疫组。质粒 Ｄ Ｎ Ａ 免疫鸡攻毒后有４０ ％ 的鸡可耐过强毒的攻击,说明 Ｓ１ 基因在体内获得了表达并使鸡产生了一定的免疫力。     

应用Dot-ELISA检测鸡毒支原体血清抗体

应用Ｄｏｔ－ＥＬＩＳＡ检测鸡毒支原体血清抗体＠郭建华＠陈明勇＠陈德威￥中国农业大学实验动物研究所应用Ｄｏｔ┐ＥＬＩＳＡ检测鸡毒支原体血清抗体郭建华＊陈明勇陈德威（中国农业大学实验动物研究所,北京海淀１０００９４）鸡毒支原体（ＭＧ）为慢性呼吸道病（ＣＲＤ）的...     

用双抗体夹心ELISA法检测鸡病毒性关节炎病毒的研究

应用鸡病毒性关节炎病毒Ｕ．ＣｏｎｎＳ１１３３株，建立了检测鸡病毒性关节炎病毒抗原的双抗体夹心ＥＬＩＳＡ法。用该法检测三组接毒鸡的关节液，接毒后３天即可检出阳性，阳性率为５８．３％；发病严重的４～１１天阳性检出率达９５７％，１４天阳性率为５０％；１７天阳性率为３１．３％；２０天以后则全部为阴性。用该法对大肠杆菌（Ｅ．ＣｏＬｉ）、葡萄球菌（Ｓｔａｐｈｙｌｏｃｏｃｃｕｓ）、败血支原体（ＭＧ）、滑膜支原体（ＭＳ）、新城疫病毒（ＮＤＶ）、传染性支气管炎病毒（ＩＢＶ）、传染性脑脊髓炎病毒（ＡＥＶ）进行检测，结果均为阴性。试验表明，我们建立的双抗体夹心ＥＬＩＳＡ法，能早期、特异、敏感地检出鸡病毒性关节炎病毒抗原，从而解决了对该病早期诊断及类症鉴别带来的困难。     

鸡传染性法氏囊病—新城疫二联峰胶灭活苗的研制

用自行分离鉴定的鸡法氏囊病病毒（ＤＦＣ３Ｖ株）与Ｉ型标准毒株（Ｄ７８株）和新城疫病毒（ＬａＳｏｔａ株）联合研制的蜂胶灭活苗,经实验室和田间试验证明,雏鸡肌肉或皮下注射０．５ｍｌ／只,注后７天产生免疫抗体,攻毒后保护率为６０％,注后１４天功玫毒保护率为１００％,免疫后１８０天,攻毒保护率为８０％,本苗与白油佐剂苗免疫效力对比试验结果表明,蜂胶佐剂苗免疫效和产生白油佐剂苗为快而持久,该苗保存于４～８℃     

鸡传染性法氏囊病-新城疫二联蜂胶灭活苗的研制

用自行分离鉴定的鸡法氏囊病病毒（ＤＦＣ３Ｖ株）与Ⅰ型标准毒株（Ｄ７８株）和新城疫病毒（ＬａＳｏｔａ株）联合研制的蜂胶灭活苗、经实验室和田间试验证明,雏鸡肌肉或皮下注射０．５ｍｌ／只,注后７天产生免疫抗体,攻毒后保护率为６０％;注后１４天攻毒保护率为１００％;免疫后１８０天,攻毒保护率为８０％。本苗与白油佐剂苗免疫效力对比试验结果表明,蜂胶佐剂苗免疫效力产生较白油佐剂苗为快而持久。该苗保存于４～８℃有效期为６个月。本苗无毒、副作用,安全性能良好,易于注射,并具有快速增重,提高产蛋率的作用。应用本苗接种现地多品系鸡２万余只,均获得满意效果。     

鸡传染性鼻炎不同茵株的交叉保护性研究

在分离的６株传染性鼻炎茵株中择优选取其中４株，分别制成油乳剂灭活苗，免疫７周龄ＳＰＦ鸡，免疫３周后分别用分离茵株攻毒。结果ＨＰＧ－ＨＺ株对各茵株的保护效果最好，平均保护率达７６％以上，而用标准株ＨＰＧ－００８３株制成的疫苗，对各分离株的平均保护率只有６０％。     

副鸡嗜血杆菌16 S rDNA PCR检测方法的建立

根据副鸡嗜血杆菌的16 S rDNA基因序列设计一对特异性引物XZIC1和XZIC2,对6株副鸡嗜血杆菌进行PCR扩增。结果显示,该对引物对6株副鸡嗜血杆菌均扩增出与预期大小相一致的282bp片段,而对鸡毒支原体、禽巴氏杆菌、鸡传染性支气管炎病毒、鸡新城疫病毒、大肠埃希菌、鸡白痢沙门菌、禽流感病毒(H9)、鸡喉气管炎病毒及葡萄球菌等9种病原体的扩增结果均为阴性。该PCR敏感性结果表明,本方法可以检测到10pg的副鸡嗜血杆菌DNA模板。采用引物XZIC1和XZIC2,对分别用副鸡嗜血杆菌ctcc253、ctcc255、ctcc257、ctcc269株感染SPF鸡的临床病料DNA进行PCR扩增,均可扩增出单一的282bp的片段。     

Glycoconjugate expression in normal hepatoid glands and hepatoid gland adenomas and carcinomas in dogs

Although neoplastic changes in canine hepatoid perianal glands (HPG) are quite common, the biological behaviour is sometimes difficult to assess on the basis of the histopathological examination. In an attempt to detect differences in the glycoconjugate expression between normal and neoplastic HPG, and to verify their relation to the degree of neoplastic progression, normal and neoplastic HPG were studied in 13 dogs, using 11 biotinylated lectins. In HPG adenomas the majority of the cells did not stain or stained weakly after incubation with pokeweed mitogen, LCA and UEA-I. In HPG carcinoma the basal cells lost the specific binding for WGA while heterogeneous distribution of conconavalin-A staining was observed.     

The effect of Holistic Planned Grazing™ on African rangelands: a case study from Zimbabwe

Holistic Planned Grazing? (HPG) is purported to have positive long-term effects on rangelands, enhancing ecosystem services. Given comparable environmental templates, but different management regimes, vegetation monitoring and landscape function analysis showed the Africa Center for Holistic Management (ACHM) at Dimbangombe had a significantly higher rangeland condition (composition, cover, standing crop and soil health) than adjacent Sizinda (SCR) and Monde (MCR) communal rangelands. Overall grazer density on ACHM is 42% higher than that of SCR (no data for MCR). Finer-scale satellite collar data for ACHM yielded a calculated stocking rate of 0,55 LSU ha^-1 y^-1 or 24 590 kg km^-2, which constitutes high-density grazing. An energy flow estimate shows that the grazing resource would, on average, not be limiting for livestock on ACHM but limiting on SCR. HPG may include an element where kraals are inserted into degraded rangelands for a short period. Overall, ACHM shows stable perennial composition with smaller tufts significantly closer together. A similar result was visible in SCR where maize yields were visibly higher on kraaled areas than on adjacent untreated fields. HPG yields positive long-term effects on ecosystem services (soils and vegetation) and points to the HPG approach enhancing the sustainability of livestock and wildlife in this environment.     

Effect of dietary protein on intake,nutrients utilization,nitrogen balance,blood metabolites,growth and puberty in growing Bhadawari buffalo (Bubalus bubalis) heifers

Fifteen Bhadawari buffalo heifers of 207?±?9.78 kg mean body weight were randomly distributed into three dietary groups to evaluate the effect of protein level on nutrient utilization, nitrogen (N) balance, growth rate, blood metabolites, and puberty. All animals were offered wheat straw-berseem diets supplemented with concentrate mixtures of similar energy (2.7 Mcal/kg) and different protein levels (14.3–22 %). Animals of standard-protein group (SPG) were offered protein and energy as per requirement, while animals of low-protein group (LPG) and high-protein group (HPG) were fed 20 % less and 20 % more protein, respectively, than SPG. Feed dry matter (DM) and metabolizable energy (ME) intake (% body wt. and g/kg w^0.75) were similar for all three diets; however, the crude protein (CP) and digestible crude protein (DCP) intake on percent body weight and per kilogram metabolic weight was higher (P?<?0.05) in HPG than in SPG or LPG. Digestibility of CP, cellulose, and hemicellulose was higher (P?<?0.05) in HPG versus LPG. Fecal N excretion was similar, while urinary N excretion was highest (P?<?0.05) in HPG (74.83 g/day) compared with SPG (50.03 g/day) and LPG (47.88 g/day), which resulted in lower N retention in HPG than in the other dietary groups. Level of dietary N had no effect on blood metabolites viz. glucose, urea, and N. Digestible energy (DE) and ME contents of diets were identical, while DCP contents were higher (P?<?0.05) in HPG than in LPG. Feed and nutrient (CP and ME) conversion efficiency to produce a unit kilogram weight gain was identical among the dietary groups. Dietary protein level had no effect on the heifer’s weight and age at puberty. The mean growth rate of heifers at 240 days was higher (P?>?0.05) in SPG (330.8 g/day) than in LPG (296.7 g/day), while the animals gained more weight in January to March months and the lowest weight in May to July months. Protein level had no effect on conception rate of heifers. Results revealed that 20 % higher or less protein than the ICAR requirement had no significant (P?>?0.05) on feed intake, nutrient conversion efficiency for weight gain, heifer growth, and puberty; however, 20 % more protein increased urinary N loss.

     

热应激对家禽HPG轴结构和繁殖功能的影响及HSPs的作用

高温环境容易引起家禽热应激,造成家禽下丘脑-垂体-性腺(hypothalamic-pituitary-gonadal,HPG)轴各组织结构不同程度的损伤,进而影响家禽正常繁殖功能,给集约化饲养管理模式下家禽养殖业造成一定的损失。热休克蛋白(HSPs)是一类保护性蛋白,它能在家禽遭受高温应激时发挥分子伴侣作用,一定程度上保护机体免受高温刺激的损伤。文章对热应激条件下家禽的HPG轴各组织结构、繁殖功能的影响及HSPs的作用进行综述,为家禽生产提供相关资料。     

中药抗病毒冲剂对鸡人工混合感染鸡副嗜血杆菌和传染性支气管炎病毒的疗效观察

试验观察了中药抗病毒冲剂对鸡人工混合感染鸡副嗜血杆菌和传染性支气管炎病毒后的治疗效果。结果显示该药具有抗病毒消炎作用,且治愈率分别比对照组高15.4%和10.2%,死亡率比对照组低6.7%,该药可用于治疗由IBV和鸡副嗜血杆菌引起的呼吸道病。     

生物钟对哺乳动物生理代谢、繁殖和肠道菌群影响的研究进展

进化过程中生物钟通过将合成代谢和分解代谢两种代谢过程进行时间上的分离,优化代谢效率;同时使动物机体的代谢循环与睡眠/活动循环同步,维持基本的代谢节律。哺乳动物的繁殖性能主要受到下丘脑-垂体-性腺轴的调控。下丘脑视交叉神经上核的主生物钟能够产生自发性振荡并且感受光周期的变化,引发褪黑素分泌的变化。褪黑素(MT)作为一种重要的节律调节因子和生殖激素,介导下丘脑-垂体-性腺轴各部分激素的节律性变化,进而调控哺乳动物繁殖性能。同时肠道菌群的变化作为一种繁殖障碍的反映逐渐引起人们的关注。本文将重点阐述昼夜节律对宿主能量代谢、繁殖性能以及肠道菌群之间的相互作用,主要包括中枢生物钟视交叉神经上核(SCN)通过褪黑素介导的下丘脑-垂体-性腺轴各部分激素的节律性变化,进而调控哺乳动物的繁殖节律。     

Chlortetracycline modulates acute phase response of ex vivo perfused pig livers, and inhibits TNF-alpha secretion by isolated Kupffer cells

Tetracyclines have been shown to have anti-inflammatory effects in addition to their antimicrobial action. We investigated the effects of in vivo administration of chlortetracycline (CTC) on ex vivo perfused pig livers. The retention and clearance of Salmonella choleraesuis, production of acute phase proteins C-reactive protein (CRP), and haptoglobin (HPG) by whole livers were studied. The in vitro modulation by CTC of TNF-alpha secretion by pig Kupffer cells (KC) was also studied. Pigs were dosed orally with CTC for three days, and given injections of Salmonella LPS 24 h before removal of the liver. Salmonella retention and clearance by livers of pigs given CTC was lower than by control livers (p < 0.01 and p < 0.05, respectively). We demonstrated an increase of CRP and HPG by livers from control pigs after a three-hour perfusion while pigs from CTC pretreated pigs varied in this response. Further, CTC decreased the secretion of TNF-alpha by cultured KC incubated in vitro with LPS. Modulation of TNF-alpha production by CTC suggests a potential for attenuating the inflammatory response. However, this possible beneficial action of CTC was accompanied by a significant decline in the antimicrobial effect of the liver.     

Kisspeptin as a master player in the central control of reproduction in mammals: An overview of kisspeptin research in domestic animals

The hypothalamo‐pituitary‐gonadal (HPG) axis is the regulatory system for reproduction in mammals. Because secretion of gonadotropin‐releasing hormone (GnRH) into the portal vessels is the final step at which the brain controls gonadal activities, the GnRH neuronal system had been thought to be central to the HPG axis. A newly discovered neural peptide, kisspeptin, has opened a new era in reproductive neuroendocrinology. As shown in a variety of mammals, kisspeptin is a potent endogenous secretagogue of GnRH, and the kisspeptin neuronal system governs both the pulsatile GnRH secretion that drives folliculogenesis, spermatogenesis and steroidogenesis, and the GnRH surge that triggers ovulation in females. The kisspeptin neuronal system is therefore considered a master player in the central control of mammalian reproduction, and kisspeptin and related substances could therefore be valuable for the development of novel strategies for the management of fertility in farm animals. To this end, the present review aimed to summarize the current research on kisspeptin signaling with a focus on domestic animals such as sheep, goats, cattle, pigs and horses.     

The reproductive system at the neuroendocrine-immune interface: focus on LHRH,estrogens and growth factors in LHRH neuron-glial interactions

Bidirectional communication between the neuroendocrine and immune systems plays a pivotal role in health and disease. Signals generated by the hypothalamic-pituitary-gonadal (HPG) axis (i.e. luteinizing hormone-releasing hormone, LHRH, and sex steroids) are major players coordinating the development immune system function. Conversely, products generated by immune system activation exert powerful and longlasting effects on HPG axis activity. In the central nervous system (CNS), one chief neuroendocrine-immune (NEI) compartment is represented by the astroglial cell population and its mediators. Of special interest, the major supporting cells of the brain and the thymus, astrocytes and thymic epithelial cells, share a similar origin and a similar set of peptides, transmitters, hormones and cytokines functioning as paracrine/autocrine regulators. This may explain some fundamental analogies in LHRH regulation of both cell types during ontogeny and in adult life. Hence, the neuropeptide LHRH significantly modulates astrocyte and thymic cell development and function. Here we focus this work on LHRH neuron-glial signaling cascades which dictate major changes during LHRH neuronal differentiation and growth as well as in response to hormonal manipulations and pro-inflammatory challenges. The interplay between LHRH, growth factors, estrogens and pro-inflammatory mediators will be discussed, and the potential physiopathological implications of these findings summarized. The overall study highlights the plasticity of this intersystem cross-talk and emphasize neuron-glial interactions as a key regulatory level of neuroendocrine axes activity.