保持公羊精液卫生无菌的措施

公羊包皮、四肢被毛、母台羊、采精及精液处理环境条件、饲养条件、人员操作、精液稀释液等十大因素可能是造成精液污染的主要因素。因此,必须从上述各方面采取技术措施保持精液卫生无菌。     

绿脓假单胞菌致死海豚的病理变化

1997年～1998年青岛市海豚表演馆饲养的3只海豚小青、小红、小黑分别于1997年9月、1998年2月、5月因绿脓假单胞菌感染而引起发病. 　　……     

初情期前母猪垂体细胞LH和FSH的释放及其对GnRH类似物的反应

利用垂体细胞单层培养模型研究了30，60，90，120和150日龄北京黑猪母猪垂体细胞LH和FSH的释放及其对LRH－A3反应能力。结果表明，猪垂体细胞LH和FSH释放对LRH－A3的反应呈S形剂量依赖型同线。LH基础释放量和LRH－A3刺激的最大释放量在不同日龄间没有显著差异，说明初情期前母猪垂体细胞已达最大LH释放和对GnRH反应的能力。FSH的基础释放量和LRH－A3刺激的最在释放量在30日龄与60日龄之间无差异，但90日龄以后垂体细胞FSH的释施量随日龄增大而降低，提出可能由于垂体在体内时受过抑制素的作用。     

猪传染性胃肠炎诊断与不同治疗方法的疗效观察

本研究针对鱼台县疑似患猪传染性胃肠炎的30～45日龄仔猪,通过临床症状、病理剖检和猪传染性胃肠炎病毒抗体检测ELISA诊断试剂盒确诊为猪传染性胃肠炎。随机抽取四圈57头患猪,按圈分成4组,分别用黄芪多糖-紫锥菊注射液+复方硫酸安普霉素注射液穴位注射、黄藤素注射液+氟苯尼考注射液、黄芪多糖注射液+烟酸诺氟沙星溶液、利巴韦林注射液+硫酸庆大霉素注射液治疗。试验结果表明:黄芪多糖-紫锥菊注射液+复方硫酸安普霉素注射液穴位注射的组方在该地区的治疗效果最好,其次是黄藤素注射液+氟苯尼考注射液的组方、黄芪多糖注射液+烟酸诺氟沙星溶液组方,利巴韦林注射液+硫酸庆大霉素注射液的组方的效果最差。     

Immune responses of orange-spotted grouper,Epinephelus coioides,against virus-like particles of betanodavirus produced in Escherichia coli

Betanodaviruses are the causative agents of viral nervous necrosis (VNN), a serious disease of cultured marine fish worldwide. Virus-like particles (VLPs) are one of the good novel vaccine candidates to control this disease. Until now, betanodavirus vaccine studies mainly focused on the humoral immune response and mortality after virus challenge. However, little is known about the activation of genes responsible for cellular and innate immunity by vaccines. In the present study, VLPs of orange-spotted grouper nervous necrosis virus (OGNNV) were produced in prokaryotes and their ability to enter Asian sea bass cells was the same as native virus, suggesting that they possess a similar structure to OGNNV. VLPs immunogenicity was then determined by intramuscularly vaccinating Epinephelus coioides at different concentrations (1.5 or 15 μg g^?1 fish body weight, FBW) and immunizing frequencies (administration once, twice and thrice). A single vaccination with the dosage of 1.5 μg g^?1 FBW is enough to provoke high titer antibodies (average 3 fold higher than that of negative control) with strong neutralizing antibody titer as early as 1 week post immunization. Furthermore, quantitative PCR analysis revealed that eleven genes associated with humoral, cellular and innate immunities were up-regulated in the liver, spleen and head kidney at 12 h post immunization, correlating with the early antibody response. In conclusion, we demonstrated that VLP vaccination induced humoral immune responses and activated genes associated with cellular and innate immunity against betanodavirus infection in orange-spotted grouper.     

Leucine markedly regulates pancreatic exocrine secretion in goats

Four goats (30.1 ± 1.3 kg) with common bile duct re‐entrant catheter and duodenal catheter were used to evaluate the effects of duodenal leucine infusion on pancreatic exocrine secretion and plasma parameters with two 4 × 4 Latin square design experiments. In the long‐term infusion experiment, goats were fed twice daily [700 g/day, dry matter (DM) basis] at 8:00 and 18:00 hours and were duodenally infused with 0, 3, 6, 9 g/day leucine for 14 days. Pancreatic juice and jugular blood samples were collected over 1‐h intervals for 6 h daily from d 11 to 14 days to encompass a 24‐h day. In the short‐term experiment, goats were infused leucine for 10 h continuously at the same infusion rate with Experiment 1 after feed deprivation for 24 h repeated every 10 days. Pancreatic juice and blood samples were collected at 0, 1, 2, 4, 6, 8 and 10 h of infusion. The results showed that the long‐term leucine infusion did not affect pancreatic juice secretion, protein output, trypsin and lipase secretion and plasma insulin concentration, but linearly increased α‐amylase secretion. No changes in pancreatic protein and lipase secretion were observed in the short‐term infusion. Pancreatic juice and α‐amylase secretion responded quadratically, with the greatest values observed in the 3 and 6 g/day leucine respectively. Trypsin secretion linearly decreased, while plasma insulin concentration increased linearly with increased leucine infusion. The results demonstrated that duodenal leucine infusion dose and time dependently regulated pancreatic enzyme secretion not associated with the change in plasma insulin concentration.     

Identification of lactic acid bacteria in the feces of dairy cows fed whole crop maize silage to assess the survival of silage bacteria in the gut

In order to assess the survival of lactic acid bacteria (LAB) in whole crop maize silage in the gut of dairy cows, one representative silage sample and three different feces samples were collected from dairy cows on three dairy farms in Hua Bei, China and three dairy farms in Kyushu, Japan. The composition of the bacterial community was examined by denaturing gradient gel electrophoresis and quantitative polymerase chain reaction. Lactobacillus acetotolerans was detected in all bunker‐made maize silage samples, regardless of the dairy farm or sampling region from which they were sourced. A total of eight LAB species were detected in the maize silage samples, of which three (L. acetotolerans, L. pontis and L. casei) appeared to survive digestion. The populations of L. acetotolerans in silage and feces were 10^6–7 and 10^3–4 copies/g, respectively, indicating that, even for the LAB species showing potential survival in the gut, competition in this niche may be harsh and the population may substantially decrease during the digestion process. It may be difficult for silage LAB to survive in the gut of silage‐fed dairy cows, because marked decrease in population can take place during the digestion process, even for surviving species.     

中国荷斯坦牛初产日龄遗传评估及全基因组关联分析

基于高通量SNPs测序的全基因组关联分析为奶牛繁殖性状相关基因的探索提供了契机。本研究基于课题组前期中国荷斯坦牛基因组测序芯片的结果,通过DMU(v 6.0)采用AI-REML结合EM算法的动物模型对北京地区2001-2011年10年间19 111头中国荷斯坦母牛初产日龄记录进行遗传参数估计,并应用PLINK(v 1.07)将大群估计的2 172头中国荷斯坦母牛初产日龄性状的育种值(EBV)作为表型值,进行基于无关群体设计的全基因组关联分析。通过全基因组水平的Bonferroni校正,共检测到1 700个SNPs与初产日龄显著相关。选取P值达到10-15的43个SNPs进行初步分析,其中12个位于X染色体上。显著SNPs上下游200kb范围内存在KLHL4、TRAM1、TRAM2、ZNF438、MATK等繁殖障碍疾病相关基因。7号染色体1 Mb(20.42~21.52 Mb)区域内多个SNPs位点与初产日龄显著相关。这些基因和区域可以作为影响初产日龄性状的重要候选基因和区域,为揭示奶牛繁殖性状的分子遗传基础积累了素材。     

饲粮锌和钙水平对产蛋鸡生产性能、血液生化指标和组织中锌含量的影响

试验在玉米-豆饼型基础饲粮中(含锌29.2ppm)添加不同水平锌和钙研究了饲粮锌和钙水平对蛋用型鸡产蛋期生产性能、血液生化指标和组织中锌含量的影响。结果表明:1.仅喂未加锌的基础饲粮的试验鸡开产晚(P<0.05),产蛋率低(P<0.05)、蛋重小(P<0.05)、产蛋量少(P<0.01)、饲料利用效率差(P<0.01)、破壳率高(P<0.01)。饲粮加锌1000ppm与加锌40ppm对照相比,生产性能无显著差异。饲粮高钙对产蛋鸡生产性能无不良影响。2.血清碱性磷酸酶活性随饲粮加锌水平的提高而显著提高(P<0.01),但不受饲粮钙水平显著影响(P>0.05)。饲粮加锌1000ppm使血清总蛋白含量(P<0.01)、血清白蛋白和球蛋白含量(P<0.05)显著降低。饲粮高钙使血清总蛋白含量(P<0.01)和白蛋白含量(P<0.05)显著降低,而球蛋白含量不受影响(P>0.05)。3.随饲粮加锌水平的提高,肝脏(P<0.01)、胰脏(P<0.01)和胫骨(P<0.01)中锌含量大幅度升高;血液(P<0.01)、肾脏(P<0.01)和肺脏(P<0.05)中锌含量升高幅度较小;而输卵管(P>0.05)、心脏(P>0.05)和肌肉(P>0.05)中锌含量无显著变化。饲粮高钙使肝脏(P<0.05)和肌肉(P<0.01)中锌含量显著降低,对其它器官无显著影响(P>0.05)。     

家蚕消化液对几种外源性酶活性的影响

通过体外试验和经口添食试验表明,家蚕消化液对纤维素酶和果胶酶具有明显的 抑制作用.分析认为,这是由于消化液的强碱性或消化液中存在的蛋白酶的分解作用 所致.因此,利用外源性消化酶的可能途径是先经酶促反应,将大量纤维素或果胶等 转变成可吸收利用的还原糖形态,然后进行给饵.