饲粮n-6/n-3多不饱和脂肪酸比例对畜禽健康和产品品质的影响

现今人类膳食中n-6多不饱和脂肪酸(PUFA)大多都是过量的,但n-3 PUFA却严重不足.研究表明,n-6/n-3 PUFA比例平衡对畜禽健康和产品品质有着重要意义,n-6/n-3 PUFA比例平衡成为当下最受关注的问题.本文综述了n-6/n-3 PUFA比例平衡的营养生理作用以及对畜禽产品品质的影响及如何改善畜禽产品中的n-6/n-3 PUFA比例.     

饵料中的维生素B6对日本沼虾部分免疫功能的影响

[目的]探讨饵料中维生素B6对日本沼虾部分免疫功能的影响。[方法]在温度为18—23℃、pH值为（7．50±0．10）的条件下,研究了饵料添加不同水平的维生素B6（0、40、80、160、240mg／kg）对日本沼虾部分免疫功能的影响。[结果]随着饵料中维生素B6含量的增加,日本沼虾肌肉中活性氧含量下降,维生素B6含量为80mg／kg时,其活性氧含量降至最低水平,但随着维生素B6含量的继续增加,其活性氧含量迅速上升。饵料中添加一定量的维生素B6可明显提高日本沼虾肌肉中SOD的活性,当添加量为80mg/kg时,SOD活性显著高于对照组。[结论]添加一定量维生素B6可明显提高日本沼虾肌肉中SOD的活性,能够清除机体内由于缺乏维生素B6产生的活性氧自由基,减轻自由基对机体的伤害,从而提高日本沼虾机体的免疫力。     

Plant Species Composition and Forage Production 14 Yr After Biosolids Application and Grazing Exclusion

This paper examines the effects of a single surface application of biosolids (at 20 dry Mg ha^{? 1}) on plant species composition, forage quality and quantity, and C stocks after 14 yr of rest in rangelands of the Central Interior of British Columbia. More than two times the aboveground biomass of grasses and the percent cover of plant litter were found in the biosolids treatment relative to the control, along with reductions in bare soil and microbiotic crust cover. Significantly greater plant uptake of all macronutrients (C, N, P, K, S, Ca, and Mg); most micronutrients (B, Cu, Mn, Mo, and Zn); and Al occurred in the biosolids treatment. P and Cu were the only two nutrients to be more concentrated in the biosolids-treated forage relative to the control forage, while N, Mg, and protein were more concentrated in the control forage. No significant difference in forage digestibility was found between biosolids and control treatments. Bluebunch wheatgrass, the late-seral native grass species, had significantly increased cover and aboveground biomass in the biosolids treatment relative to the control; however, between 2006 and 2016, non-native Kentucky bluegrass had reached > 25% cover in the biosolids plots, perhaps restricting the full recovery of bluebunch wheatgrass. Our findings indicate that biosolids application to ungrazed rangeland can increase long-term forage production and reduce bare soil. However, at our study site biosolids application also led to a long-term shift in the plant community composition away from the late-seral (i.e., bluebunch wheatgrass) trajectory, and the effects of this shift on rangeland health and productivity require further investigation.     

Interactions between dietary fatty acids and hepatic gene expression in livers of pigs during the weaning period

The aim of the present study was to evaluate the impact of dietary fatty acids (FA) during the weaning period on expression of genes involved in the oxidation and metabolism of FA (peroxisome proliferator-activated receptor (PPAR-), stearoyl-CoA-desaturase (SCD), Δ6-desaturase (D6D), acetyl CoA carboxylase (ACC) and fatty acid synthase (FAS)). Liver samples were obtained from littermates, either on day 28 of age just before weaning, or at day 56 after the 4 weeks ad lib. provision of 5% of either animal fat, fish oil or sunflower oil. In conclusion, genes involved in the regulation of FA conversion (SCD, D6D) were influenced by the n-6 to n-3 ratio, whereas the FA oxidation, as indicated by the expression of PPAR-, was highly likely regulated by the hepatic ratio between mono- and poly-unsaturated FA. Furthermore, weaning and/or age affected the hepatic expression of genes involved in FA synthesis and conversion, but not the expression of PPAR-.     

对C57BL／6小鼠超排效果的研究

本文以近交系C57BL／6小鼠为实验对象．研究注射不同剂量的PMSG和hCG对小鼠超排效果的影响。取C57BL／6小鼠各30只,按照注射剂量不同分为A、B、C三组,每组10只,A组注射PMSG2．5IU,HCG2．5IU,B组注射PMSG5．0IU,HCG5．0IU,C组注射PMSG7．5IU,HCG7．5IU。每只小鼠腹腔注射PMSG,间隔48h后分别注射HCG进行超数排卵,再与性成熟同系公鼠合笼,次日早上检查阴道栓．有栓雌鼠用颈椎脱臼法处死。在实体显微镜下由输卵管膨大部冲卵．收集卵母细胞置于盛有M2培养液的表面皿中检查计数．分析超排效果。结果表明。C57BU6小鼠B组的平均取卵数极显著高于A组的平均取卵数（P〈0．05）;B组的平均取卵数显著高于C组的平均取卵数（P〈0．05）;C组与A组的平均取卵数差异不显著（P〉0．05）。     

Hypophosphatemia Induced by Dietary Aluminium Hydroxide Supplementation in Growing Pigs: Effects on Erythrocytes,Myocardium, Skeletal Muscle and Liver

Håglin, L., B. Essén-Gustavsson and A. Lindholm: Hypophosphatemia induced by dietary aluminium hydroxide supplementation in growing pigs: Effects on erythrocytes, myocardium, skeletal muscle and liver. Acta vet. scand. 1994, 35, 263-271.– Three groups of pigs were studied during and after 10 weeks of treatment with either Al(OH)₃ (Al[OH]₃-group, n=8) to induce hypophosphatemia, A1P0₄ (AlP0₄-group, n=8, aluminium control without hypophosphatemia) or no addition to the feed (control group, n=8). Blood samples were taken at the start of the experiment and after 3, 6 and 10 weeks and were analyzed for phosphate, calcium and 2,3-diphosphoglycerate (2,3-DPG). Samples from myocardium, skeletal muscle and liver were obtained in connection with exsanguination and analyzed for glycogen, adenosine-tri-phosphate (ATP), creatine phosphate (CP), glucose-6-phosphate (G-6-P) and lactate. The Al(OH)₃-group became hypophosphatemic and hypercalcémie with low levels of 2,3-DPG in erythrocytes within 3 weeks and showed a retarded growth rate. After 10 weeks the Al(OH)₃-group had low levels of ATP in myocardium as compared with the control-group and low levels of G-6-P as compared with the AlP0₄-group. No disturbances on electro-cardiograms registered at rest could be documented. G-6-P concentration was low in the biceps muscle in the Al(OH)₃-group as compared with the AlP0₄-group and in the liver low G-6-P concentration was seen in addition to high lactate concentration. The fibre type composition in M. Longissimus did not differ between groups, but the Al(OH)₃-group had, due to retardation in growth, smaller mean fibre-areas than pigs in the AlP0₄-group. Hypophosphatemia gave rise to high serum calcium levels, low concentration of 2,3-DPG in erythrocytes and influenced G-6-P concentration in skeletal muscle, G-6-P and ATP in myocardium, G-6-P and lactate in liver. Retarded growth was one serious consequence of hypophosphatemia and the disturbed energy metabolism.     

猪繁殖与呼吸综合征病毒河北地方株ORF6基因的克隆及原核表达

从河北沧州分离到一株疑似猪繁殖与呼吸综合征病毒,接种Marc-145细胞,经4代盲传,出现细胞病变,经鉴定为PRRSV,命名为HB-3(cz)株。根据GenBank公布的PRRSV JXA1株ORF6基因的核苷酸序列,设计并合成一对特异性引物(P1/P2),用RT-PCR方法扩增完整ORF6基因,将扩增产物连接到pGM-T载体并转化克隆菌,阳性重组质粒PGM-M进行序列测定与分析。后将克隆质粒PGM-M双酶切后连接原核表达载体pET-32a(+),在Rosseta-DE3中成功获得表达,经Western-blotting分析表明,表达蛋白与阳性血清发生特异性反应。     

猪骨形态发生蛋白-6基因多态性及其与产仔性能的关联性分析

试验旨在研究猪骨形态发生蛋白-6（bone morphogenetic protein 6, BMP-6）基因多态性及其与产仔性能的关联。采用PCR-SSCP技术检测了野猪、民猪、长白猪、北京黑猪、法系大白猪5个猪种268个个体BMP-6基因的多态性,并分析了BMP-6基因多态性与法系大白猪产仔性能的关联性。结果表明,猪BMP-6基因CDS区1104位存在1个G→A的同义突变,产生AA、AB、BB 3种基因型,其中在野猪和民猪中,A等位基因频率高;在长白猪、北京黑猪和法系大白猪中,B等位基因频率高。不同基因型对法系大白猪产仔数和产活仔数的影响差异显著（P<0.05）,初步认为BMP-6基因多态性与产仔性能显著关联。     

过表达IL-6对山羊毛囊干细胞增殖和迁移的影响

旨在通过在山羊毛囊干细胞(HFSCs)中过表达炎症因子白细胞介素6(IL-6),探讨其对山羊HFSCs增殖和迁移的影响,阐明MAPK/ERK信号通路在山羊HFSCs增殖和迁移过程中发挥的作用。本试验通过构建pXJ40-myc-IL-6过表达载体,瞬时转染到山羊HFSCs中,以空载体细胞为空白对照组。利用Western blot定量检测IL-6蛋白的表达,MTT法检测山羊HFSCs的增殖活力,划痕试验判定山羊HFSCs的迁移能力,最后采用Westernblot检测山羊HFSCs中MAPK/ERK和P38信号通路中关键激酶的表达水平。结果表明,将获得的IL-6过表达载体转染至山羊HFSCs3d后,与对照组比较,山羊HFSCs的增殖活力出现抑制,且抑制效果持续至第7天(P<0.05)。IL-6过表达载体转染至山羊HFSCs24h后,处理组划痕部位的愈合率达到84.2%,显著低于对照组的98.5%(P<0.01)。与对照组相比,MAPK/ERK信号通路中的关键激酶ERK1/2的磷酸化水平(p-ERK1/2)显著下调(P<0.01),P38信号通路中的关键激酶p38的磷酸化水平(p-p38)表达量上调,但差异无统计学意义(P>0.05)。综上所述,过表达IL-6基因对山羊HFSCs的增殖和迁移能力具有抑制作用,且过表达IL-6可能是通过MAPK/REK信号通路对山羊HFSCs增殖和迁移发挥负性调控作用,以上结果为揭示山羊HFSCs的迁移及组织修复机制的研究提供依据。     

Pathogenicity of a Strain of H5N6 Subtype Avian Influenza Virus in Ducks and Mice

To investigate the pathogenicity of A/Hero/Guangdong/C1/2013(H5N6), an AIV strain isolated from Heron on ducks and mice, pathogenicity of this new virus strain and changing of histopathology as well as a preliminary study on its biological characteristics were studied by virus challenges test via intranasal and eye-drop and in chicken via jugular vein injection.Results showed that the EID₅₀ of this strain of virus was 10^-8.16/0.1 mL in embryonated chicken eggs and the intravenous inoculation of pathogenic index (IVPI) was 2.76.In ducks and mice, the 50% lethal doses (LD₅₀) of it were determined to be 10^-4.0/0.2 mL and 10^-4.67/0.05 mL, respectively.Symptoms of infection included loss of appetite, depression, swollen head and tears after being infected with 10⁶ EID₅₀ per duck by intranasal and eye-drop administration.Most of ducks died 4 to 7 days post-infection, liver, lung and kidney still eliminated toxicants at day 7 post-infection.Anatomy showed symptoms of pericardial effusion, pulmonary congestion and kidney enlargement, while pathological section showed pathological change like karyopycnosis and inflammatory cell infiltration in heart, liver, kidney and spleen.Mice developed symptoms of infection like loss of appetite, depression, shaggy coat and ruffled coat after being infected with 5×10⁵ EID₅₀ per mouse by intranasal and eye-drop administration.Most of the infected mice died 5 to 7 days post-infection and only liver still eliminated toxicants at day 7 post-infection.Although organ anatomy showed no obvious pathological changes, pathological section showed pathological changes like karyopycnosis and inflammatory cell infiltration in heart, kidney and lung.Our research demonstrated that this H5N6 subtype AIV had a strong pathogenicity and could be defined as a highly pathogenic AIV strain as its IVPI was greater than 1.2.Our work laid a theory foundation for study, prevention and control of H5N6 subtype AIV.