蛋氨酸水平对羔羊体况发育、消化道组织形态及血清抗氧化指标的影响

本试验旨在研究蛋氨酸水平对羔羊体况发育、消化道组织形态及血清抗氧化指标的影响。试验选取12对7日龄断母乳的湖羊双胞胎公羔,采用配对试验设计,分为对照(CON)组和低蛋氨酸(LM)组,1对双胞胎羔羊分到不同的组中。试验分2个阶段进行,第1阶段(8~56日龄),CON组羔羊饲喂基础代乳粉和基础开食料;LM组羔羊饲喂的代乳粉和开食料在CON组基础上分别全部扣除(0.70%和0.40%)额外添加的蛋氨酸,其余营养水平保持一致。第2阶段(57~84日龄),2组羔羊停止饲喂代乳粉且饲粮均为基础开食料。在56和84日龄,各选取6对双胞胎羔羊进行屠宰,分离消化道组织,采集血清样品。结果表明:1)在采食量方面,LM组羔羊对蛋氨酸采食量在8~56日龄、8~84日龄阶段均极显著低于CON组(P0.01),而干物质采食量却均显著高于CON组(P0.05);在体尺指标方面,56日龄,LM组除体重、体斜长、胸围和体长指数显著低于CON组(P0.05)外,其他体况发育指标2组间均无显著性差异(P0.05);84日龄,2组间体况发育指标均无显著性差异(P0.05)。2)56日龄,LM组羔羊的瘤胃乳头宽度显著低于CON组(P0.05),2组羔羊的其他消化道形态发育指标差异不显著(P0.05)。3)56日龄,LM组羔羊血清中超氧化物歧化酶活性极显著低于CON组(P0.01);84日龄,LM组羔羊血清中除谷胱甘肽过氧化物酶活性显著低于CON组(P0.05)外,2组羔羊的其他血清抗氧化指标差异均不显著(P0.05)。结果提示,饲粮低蛋氨酸水平抑制了羔羊体况(体重、体斜长、胸围、体长指数)发育及瘤胃乳头宽度的增加,同时降低了机体血清中超氧化物歧化酶活性,然而却提高了干物质采食量;提高饲粮蛋氨酸水平后,羔羊体况发育及消化道组织形态发育也随之得到补偿,但机体抗氧化防御系统仍未得到完全改善。     

丙氨酰谷氨酰胺二肽对早期断奶仔猪抗氧化能力及肠道保护的研究

本试验旨在研究丙氨酰谷氨酰胺二肽(Ala-Gln)对早期断奶仔猪抗氧化能力和肠道保护的影响。采用完全随机化设计,选用体质量、胎次、泌乳量、产仔数相近、健康的云南撒坝母猪所产的48头仔猪(1/2♂,1/2♀),35日龄断奶,随机分成4个处理,每个处理3个重复,每个重复4头。A组为对照组,饲喂基础日粮,B、C和D组分别饲喂添加0.15%、0.30%和0.45%Ala-Gln的试验日粮。试验期为35~60日龄。结果表明,添加0.15%、0.30%和0.45%Ala-Gln可提高断奶仔猪生长性能,随饲粮Ala-Gln添加水平提高,日采食量、体质量呈二次曲线上升(P<0.05),料重比呈二次曲线降低(P<0.05)。第49日龄的仔猪血清T-AOC和T-SOD含量以二次曲线方式升高(P<0.05),血清MDA活性呈二次曲线降低(P<0.01)。小肠形态学观察结果显示,仔猪十二指肠和回肠绒毛长度以二次曲线方式升高(P<0.01),空肠绒毛长度以二次曲线方式升高(P<0.05),十二指肠和空肠隐窝深度以二次曲线方式降低(P<0.05),十二指肠、空肠和回肠绒毛长度和隐窝深度比值(V/C)以二次曲线方式提高(P<0.01)。结...     

4种短体线虫形态及rDNA-ITS的PCR-RFLP鉴定

 短体线虫隶属于垫刃目(Tylenchida Thorne, 1949),垫刃亚目(Tylenchina Chitwood, 1950),短体科(Pratylenchidae Thorne, 1949),短体亚科(Pratylenchinae Thorne, 1949),短体线虫属(Pratylenchus Filipjev, 1936),是一类重要的迁移性内寄生植物病原线虫 ^[1]。国内外已报道该属线虫百余种。其中我国已报道种类有P.alleni、 P.artemisiae、 P.coffeae、 P.crenatu、 P.cruciferus、 P.dioscoreae、 P.hexincisus、 P.loosi、 P.penetrans、 P.pratensi、 P.neglectus、 P.penetrans、 P.scribneri、 P.thornei、 P.varicaudatus、 P.vulnus及P.zeae 17种。近年来,随着世界各地贸易往来日益频繁,植物线虫的传播机会大大增加,我国口岸也先后从进境植物根围截获P.brachyurus、 P.neglectus、 P.zeae、 P.coffeae、 P.penetrans、 P.pinguicaudatus等。基于本类群线虫的重要性和国内以往的鉴定都主要单纯依据形态学特征,本研究结合形态学和rDNA的PCR-RFLP及序列分析技术对浙江和海南不同寄主上植物线虫调查时发现的4个短体线虫群体进行了鉴定。     

氮磷钾配施对保护地番茄产量及品质的影响

利用二次通用旋转组合设计，经微机分析，建立了氮磷钾与保护地番茄产量形成及果实品质的数学模型。结果表明，氮对产量形成及果实的品质影响最大。在适宜范围内，随着施氮量的增加，产量明显增加，果实中的维生素Ｃ、还原糖及有机酸的含量增加。施氮过量则产量变低，品质变劣。磷钾肥对促进番茄产量形成具有间接作用，利于提高番茄产品品质。但过量施用磷钾肥也对果实品质不利。     

重庆四面山不同林地类型优先流特征及染色形态定量评价

以重庆四面山阔叶林、针叶林、灌木林和草地为研究对象,基于碘−淀粉染色示踪试验,借助Adobe Photoshop、IPWIN等图像处理技术和数据处理方法,对土壤优先流特征及其染色形态进行定量评价。结果表明：阔叶林地、针叶林地、灌木林和草地土壤优先流分别在5～25、10～30、10～25 cm和5～20 cm发育明显,各林地垂直剖面总体上均随土层深度增加染色面积比下降。阔叶林和针叶林土壤表层0～10 cm下降迅速,灌木林随土壤深度增加呈现先下降后基本不变再下降的趋势。阔叶林和针叶林总染色面积比高于灌木林和草地,阔叶林的优先流比和优先流长度指数也分别高于针叶林、灌木林和草地。     

竹原纤维和竹粉纤维形态和化学成分分析

以3年生毛竹材为原料,研究了毛竹竹粉和竹原纤维的纤维形态和化学成分。纤维形态分析结果表明:竹原纤维的宽度(143μm)与竹粉(136μm)相当,长度(22.63 mm)远高于竹粉(0.61 mm),使其长宽比(158.25)远高于竹粉(4.49)。化学成分分析表明:竹原纤维的纤维素含量(65.6%)比竹粉(37.3%)高得多,聚戊糖含量(17.1%)略低于竹粉(20.1%)。竹粉中的木质素含量为24.5%,是竹原纤维中木质素含量(11.5%)的2倍多。竹原纤维的高纤维素含量和低木质素含量是其广泛应用于制浆造纸行业的重要原因。     

Morphological assessment of cat kidneys using computed tomography

There are numerous publications about feline renal imaging information; however, none have established reference values for kidney size using computed tomography (CT). This study aimed to determine renal size and shape as well as the morphology of renal‐related structures in clinically normal cats (Felis catus) that underwent CT. Twenty‐seven healthy cats underwent pre‐ and post‐iodinated contrast‐enhanced CT. Most cat (59%) kidneys were located at the same level. The average pre‐contrast dimensions of the left kidney included a width of 2.46 ± 0.28 cm, a length of 3.52 ± 0.44 cm and a height 2.19 ± 0.31 cm, whereas those of the right kidneys were 2.45 ± 0.27 cm, 3.54 ± 0.46 cm and 2.05 ± 0.23 cm, respectively. After contrast enhancement, kidneys were slightly enlarged though not significantly. Additionally, renal length (LK or RK) was compared with second lumbar vertebra (L2) length and abdominal aorta diameter (AO). AO was significantly larger in male cats whereas L2 length appeared longer in male cats, but was not statistically different from the female cats. The LK/L2 and RK/L2 ratios were 2.29 ± 0.23 and 2.36 ± 0.20, respectively, and the LK/AO and RK/AO were 11.72 ± 1.37 and 12.05 ± 1.47, respectively. Renal vessels were examined. The renal vein was obviously larger than the renal artery, and paired renal veins were observed periodically. This study provides CT information about the feline kidney, which may help to establish reference values and information regarding renal structure prior to surgery in practice.     

Overhead supplemental far-red light stimulates tomato growth under intra-canopy lighting with LEDs

Far-red(FR) light regulates phytochrome-mediated morphological and physiological plant responses.This study aims to investigate how greenhouse tomato morphology and production response to different durations of FR light during daytime and at the end of day(EOD).High-wire tomato plants were grown under intra-canopy lighting consisting of red(peak wavelength at 640 nm) and blue(peak wavelength at 450 nm) light-emitting diodes(LEDs) with photosynthetic photon flux density(PPFD) of 144 μmol m–2 s–1 at 10 cm away from the lamps,and combined with overhead supplemental FR light(peak wavelength at 735 nm) with PPFD of 43 μmol m–2 s–1 at 20 cm below the lamps.Plants were exposed to three durations of FR supplemental lighting including: 06:00–18:00(FR12),18:00–19:30(EOD-FR1.5),18:00–18:30(EOD-FR0.5),and control that without supplemental FR light.The results showed that supplemental FR light significantly stimulated stem elongation thereby resulting in longer plants compared with the control.Moreover,FR light altered leaf morphology toward higher leaf length/width ratio and larger leaf area.The altered plant architecture in FR supplemented plants led to a more homogeneous light distribution inside the canopy.Total plant biomass was increased by 9–16% under supplemental FR light in comparison with control,which led to 7–12% increase in ripe fruit yield.Soluble sugar content of the ripe tomato fruit was slightly decreased by longer exposure of the plants to FR light.Dry matter partitioning to different plant organs were not substantially affected by the FR light treatments.No significant differences were observed among the three FR light treatments in plant morphology as well as yield and biomass production.We conclude that under intra-canopy lighting,overhead supplemental FR light stimulates tomato growth and production.And supplementary of EOD-FR0.5 is more favorable,as it consumes less electricity but induces similar effects on plant morphology and yield.     

奥-贝球铁焊接HAZ组织性能与断口分析

利用Ｇｌｅｅｂｌｅ－１５００焊接热模拟试验机,通过改变峰值温度Ｔｍ、高温停留时间ｔｍ和冷却速度ｔ８／５,研究了奥－贝球铁焊接ＨＡＺ力学性能和断口形貌。当Ｔｍ增加时,强度σｂ下降,断口由准解理断裂形貌过渡到脆断形貌;在ｔｍ增加时,强度σｂ缓降,断口脆断逐渐明显;而当ｔ８／５增加时,强度σｂ增加,在ｔ８／５＝４０ｓ达到最高值,当进一步增加ｔ８／５,强度σｂ略有下降,断口表现为珠光体组织中铁素体与渗碳体分开特征,并证明奥氏体区是ＡＤＩ焊接接头力学性能最薄弱的区域。     

饲粮中添加卵黄抗体对断奶仔猪生长性能、血清生化指标、肠道形态及肠道微生物菌群的影响

本试验旨在研究饲粮中添加卵黄抗体对断奶仔猪生长性能、血清生化指标、肠道形态及肠道微生物菌群的影响。试验选取160头(25±1)日龄"杜×长×大"断奶仔猪,分为4个组,每个组4个重复,每个重复10头猪。各组分别饲喂以下4种饲粮:基础饲粮(对照组)、基础饲粮+0.4 kg/t硫酸黏杆菌素(抗生素组)、基础饲粮+1.0 kg/t卵黄抗体(卵黄抗体组)、基础饲粮+0.2 kg/t硫酸黏杆菌素+0.5 kg/t卵黄抗体(联用组)。试验期共计28 d。结果表明:1)与对照组相比,卵黄抗体组显著提高了断奶仔猪平均日增重(P0.05),显著降低了断奶仔猪料重比和腹泻率(P0.05),断奶仔猪平均日采食量无显著差异(P0.05)。与抗生素组相比,卵黄抗体组断奶仔猪生长性能无显著差异(P0.05),两者表现出相近的使用效果。2)与对照组相比,卵黄抗体组显著提高了断奶仔猪血清中总蛋白、白蛋白的含量(P0.05)。3)与对照组相比,卵黄抗体组显著增加了断奶仔猪回肠绒毛高度和绒隐比(P0.05),断奶仔猪十二指肠和空肠的绒毛高度、隐窝深度和绒隐比无显著差异(P0.05)。4)与对照组相比,卵黄抗体组显著降低了断奶仔猪回肠、盲肠中大肠杆菌数量(P0.05),显著增加了断奶仔猪回肠、盲肠中的乳酸杆菌数量(P0.05)。综上所述,饲粮中添加卵黄抗体能显著改善断奶仔猪生长性能,增强仔猪免疫力,提高肠道健康水平,促进有益菌生长,与抗生素有相近的使用效果,是很有发展潜力的抗生素替代品之一。