鸡褪黑激素受体基因在开产前后不同组织中的表达差异

为了从分子水平上了解鸡褪黑激素受体（MTNR）基因在开产前后不同组织中的表达差异,以β-actin基因为内标基因,运用实时荧光定量PCR方法,比较了MTNR1A、MTNR1B和MTNR1C这3个受体基因在心脏、肝脏、输卵管、卵巢、脑和视交叉各组织及在鸡开产前后表达量的差异。结果表明,MTNR1A只在开产后各组织中的表达量存在差异,其中以卵巢组织表达量最高,心脏中表达量最低。MTNR1B和MTNR1C的表达量在开产前或开产后均表现出组织间的显著差异;在开产前后的各组织中,MTNR1B的表达量均以视交叉为最高,卵巢为最低;而MTNR1C的表达量在开产前以心脏中最高,开产后在视交叉中最高,在卵巢组织中的表达量开产前后均为最低。同一组织开产后与开产前比较,MTNR1C基因在心脏、输卵管和脑组织中的表达量呈显著下调趋势。因此,3个受体基因在鸡的不同组织和生理时期存在表达差异。     

青蒿素及其衍生物的作用机理及其对鸡球虫病的防治

对青蒿素及其衍生物的作用机理及近年来其在防治鸡球虫病的应用做了较详细的综述,以期为其在防治鸡球虫病中的应用提供参考。青蒿素被用于治疗疟疾已有几百年的历史,它还具有治疗血吸虫、腹泻及清热、镇静安神的作用,但其在兽医临床中的应用还是一个新领域。     

传染性法氏囊病病毒（IBDV）人工感染SPF鸡的病理学观察

取３２０只３０～４０Ｈ龄ＳＰＦ鸡，经滴鼻和点眼接种传染性法氏囊病病毒（ＩＢＤＶ），接种后２４～７２ｈ出现死亡，病死率５１．２５％，死亡鸡剖检变化主要为法氏囊肿胀、出血，甚至呈紫葡萄样，脾脏肿大、出血，骨骼肌出血，腺胃肌胃交界处出血。病理组织学变化，呈现以法氏囊淋巴滤泡内髓质淋巴细胞坏死为主的特征性病变，并可在巨噬细胞浆内发现病毒包涵体。电镜观察，在法氏囊内淋巴细胞、异染性细胞、巨噬细胞浆内，见大量晶格状排列的病毒粒子和包涵体，表明ＩＢＤＶ首先损害法氏囊淋巴滤泡髓质内未成熟的Ｂ淋巴细胞，病毒在淋巴细胞内以包涵体方式增殖。     

Muscular architecture and VIP-like immunoreactive nerves in the gastroduodenal junction of the chicken

The muscular architecture and the distribution of nerves with vasoactive intestinal polypeptide-like (VIP-like) immunoreactivity were examined in the gastroduodenal junction of the chicken. Both the outer and the inner muscle layers (tunica muscularis) and the muscularis mucosae were examined. The inner muscle layer was divided into two parts, namely its inner and outer parts. The outer muscle layer was not present in the pyloric part but was found in the proventriculus and the duodenum. The muscle strands of the outer muscle layer ran longitudinally but were absent at the isthmus and the pylorus. Most of the outer part of the inner muscle layer was located in or close to the pyloric part. The muscle strands in the outer part connected the pyloric part with other regions, namely the craniodorsal muscle, the tendinous centres and the isthmus. The inner part of the inner muscle layer was widely distributed in the stomach. In the pyloric part, the muscle strands of this layer followed a circular or spiral course. The muscularis mucosae was not present in the caudodorsal and cranioventral muscles of the gizzard. In addition, VIP-like immunoreactive nerve fibres were predominantly distributed in the inner part of inner muscle layer of the pyloric part. These results suggest that the ventriculopyloric orifice and the pyloric part itself constrict with a sphincter-like action.Abbreviations VIP vasoactive intestinal polypeptide     

Work-related increases in titer of Campylobacter jejuni antibody among workers at a chicken processing plant in Miyazaki prefecture,Japan, independent of individual ingestion of edible raw chicken meat

Workers in poultry abattoirs may be frequently exposed to Campylobacter jejuni, which is a leading cause of bacterial food poisoning in Japan. The present study was conducted to measure the titers of IgG and IgA antibodies against C. jejuni among 104 female workers in a chicken processing plant in Miyazaki prefecture, Japan. Information regarding habitual ingestion of raw chicken meat and potential occupational risk factors was collected using a questionnaire. Acid extracts of four C. jejuni strains representing the genotypes most dominant in Miyazaki were used as antigens. The levels of both immunoglobulins measured by ELISA were not correlated with ingestion of edible raw chicken meat, the amount consumed in one sitting, or its frequency. Although age was correlated with antibody levels, the length of employment was not. Furthermore, the IgG and IgA levels in workers at the evisceration step were significantly higher than those at other locations in the plant. To identify the bacterial proteins recognized by the workers’ IgG and IgA antibodies, Western blotting followed by LC/MS was conducted. Flagellin was identified as the common protein recognized in the sera of workers for whom ELISA demonstrated both the highest and lowest antibody levels. We concluded that the titers of IgG and IgA against C. jejuni in workers at the processing plant had been increased by occupational exposure to Campylobacter, regardless of raw chicken meat ingestion.     

茶多酚对活性氧引起的鸡胚睾丸细胞氧化损伤的保护作用

利用精原细胞-体细胞共培养模型研究茶多酚对鸡胚睾丸细胞氧化损伤的缓解作用。结果表明:由次黄嘌呤-黄嘌呤氧化酶体系产生的活性氧可引起脂质过氧化产物丙二醛(MDA)的生成量增加、超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)的活性降低,而添加0.1μg/mL的茶多酚能降低MDA的生成量、使SOD和GSH-Px的活性恢复到对照组水平。这些结果说明,茶多酚通过抗氧化作用对活性氧引起的鸡胚睾丸细胞的氧化损伤具有保护作用。     

磺胺二甲嘧啶快速直接竞争ELISA试剂盒的研制及应用

在多克隆抗体的基础上研制一种用于检测动物源性食品中磺胺二甲嘧啶(SMZ)残留量的直接竞争酶联免疫吸附测定法(ELISA)试剂盒,并与高效液相色谱(HPLC)分析方法比较和验证.将磺胺二甲嘧啶添加到猪肝、猪肉和鸡肉样品中,用所制备的试剂盒和HPLC分析方法检测样品中的磺胺二甲嘧啶残留,并对试剂盒的灵敏度、特异性、精密度、准确度和有效期进行测定.研究结果表明,磺胺二甲嘧啶浓度在0.5～50 ng·mL-1,方法的检测灵敏度IC10 =0.47 ng·mL-1,板内平均变异系数为7.4％,板间平均变异系数为9.27％.猪肝、猪肉与鸡肉组织样品中SMZ最低检测限分别为3.91、4.81与1.59 μg·kg1.在添加10.0～50.0 μg·kg-1时,平均回收率在85％～110％.试剂盒的检测时间为12.6 min,在4℃至少可以保存6个月.研制的试剂盒可以满足猪肝、猪肉和鸡肉中磺胺二甲嘧啶残留的现场快速检测.     

肉种鸡鸡舍夏季通风降温试验

在两栋长145m，跨度5.4m的双坡式有窗封闭舍内，采用三层笼养方式分别饲养700只235日龄的艾维菌肉种鸡，将其中采用轴流式风机加湿帘纵向通风系统的一栋鸡舍作为试验组，而将另一栋采用窗户自然通风的鸡舍作为对照组，于夏季进行为期15d的试验，结果表明试验组与对照组的舍内温度在1d内明显不同，且舍外温度越高，试验组的舍内降温效果越好，相应地，试验组也减轻了肉种鸡的夏季热应激。     

氯苯胍在鸡组织中的残留消除规律研究

采用超高效液相色谱一串联质谱法（UPLC-MS／MS）研究了氯苯胍在鸡组织中的残留消除规律。白来杭鸡以含氯苯胍500mg／kg饲料饲喂7d,停药后的第0、1、3、5、7天取其肌肉、肝脏、肾脏、皮和脂肪五种组织,采用UPLC-MS／MS法测定其残留状况。结果表明,氯苯胍在肌肉中残留量较小,代谢消除比较快,2d后未检出;而在脂肪、皮和肝脏中残留量较大,代谢消除较慢。     

常山口服液抗鸡柔嫩艾美耳球虫广东分离株的疗效研究

研究旨在明确常山口服液治疗鸡球虫病的疗效和最佳给药剂量。试验选取90只14日龄健康雏鸡,随机分为9组,每组10只,即常山口服液组(分别为2.5、5.0、15.0、25.0、35.0、50.0 m L/L水剂量)、妥曲珠利组(1 m L/L水)、感染对照组和健康对照组。除健康对照组外,每只鸡接种7×104个柔嫩艾美耳球虫广东分离株的孢子化卵囊,饮水给药7 d,观察其疗效。结果显示,常山口服液各剂量组其盲肠和十二指肠的肿胀现象较感染对照组明显减轻,血液性内容物明显减少,抗球虫指数(ACI)分别为87.7、136.2、141.8、136.2、109.7和108.0,均高于感染对照组;常山口服液按5.0、15.0及25.0 m L/L水剂量给药,抗球虫指数均高于对照药物妥曲珠利组(ACI=124.8)。结果表明,人工感染条件下,常山口服液较化学药物妥曲珠利具有更好的抗球虫疗效,且作为中药提取物,疗效对比试验效果较为理想。