罗伊氏乳杆菌I5007对新生仔猪肠道形态、二糖酶活性和紧密连接蛋白表达的影响

【目的】罗伊氏乳酸杆菌是普遍存在于人和动物肠道的有益乳酸杆菌,研究表明,口服罗伊氏乳酸杆菌能显著降低腹泻的发病率和严重程度。研究罗伊氏乳酸杆菌I5007（Lactobacillus reuteri I5007）对新生仔猪肠绒毛发育和肠黏膜屏障功能的影响。【方法】试验选取9窝1日龄的杜×长×大初生仔猪,每窝挑选8头体重相近、出生状况良好的仔猪,按体重分为3组,每组3窝仔猪。即：对照组（灌服0.1%无菌蛋白胨溶液）,前4日龄灌服组（1-4 d,每日每头灌服活菌总数为1.2×10¹⁰ CFU 的L. reuteri I5007）和隔4日龄灌服组（1、5、9、13、17和21 d灌服,灌服剂量同前4日龄灌服组）。试验期21 d,试验期间仔猪由各自母猪哺乳饲喂。于试验第7、14和21 天,每个处理组随机选取4头仔猪,空腹称重、麻醉和屠宰,截取相同位置的十二指肠、空肠和回肠,测定其肠绒毛形态,并测定试验结束时（21 d）空肠和回肠二糖酶活性和紧密连接（TJ）蛋白的表达。【结果】灌服L. reuteri I5007对仔猪生长性能没有显著影响（P＞0.05）,但对不同阶段仔猪的肠道形态有不同程度的影响。7 d时,隔4日龄灌服组与对照组相比,仔猪十二指肠绒毛高度、绒毛高度/隐窝深度、杯状细胞数和回肠杯状细胞数均显著增加（P＜0.05）,前4日龄灌服组仔猪的十二指肠绒毛高度/隐窝深度、杯状细胞数和回肠杯状细胞数也均显著高于对照组仔猪（P＜0.05）,但对十二指肠绒毛高度无显著影响（P＞0.05）;14 d时,隔4日龄灌服组仔猪十二指肠的绒毛高度/隐窝深度和回肠杯状细胞数均显著高于对照组（P＜0.05）,前4日龄灌服组仔猪的回肠杯状细胞数也显著高于对照组（P＜0.05）,但却低于隔4日龄灌服组（P＜0.05）;21 d时,隔4日龄灌服组显著提高了仔猪十二指肠和回肠的杯状细胞数（P＜0.05）,前4日龄灌服组与对照组相比,仅提高了回肠杯状细胞数（P＜0.05）,反而降低了十二指肠绒毛高度/隐窝深度（P＜0.05）。另外,前4日龄灌服组仔猪空肠隐窝深度显著低于隔4日龄灌服组仔猪（P＜0.05）,但其十二指肠杯状细胞数和绒毛高度/隐窝深度均显著低于隔4日龄灌服组仔猪（P＜0.05）。在二糖酶活性上,隔4日龄灌服组仔猪空肠蔗糖酶和麦芽糖酶活性均显著高于对照组（P＜0.05）,前4日龄灌服组仅提高了仔猪空肠麦芽糖酶活性（P＜0.05）,且该组空肠蔗糖酶活性和麦芽糖酶活性均显著低于隔4日龄灌服组（P＜0.05）。隔4日龄灌服组对仔猪空肠和回肠的3种TJ蛋白（Claudin-1、Occludin和ZO-1）均有显著的促表达作用（P＜0.05）,前4日龄灌服组仔猪空肠Claudin-1、ZO-1和回肠Claudin-1的表达也均高于对照组（P＜0.05）,但是其空肠Occludin显著低于隔4日龄灌服组（P＜0.05）,且其回肠Claudin-1（P = 0.1）和ZO-1（P = 0.1）相比于隔4日龄灌服组也有降低的趋势。【结论】本试验条件下,新生仔猪隔4日龄灌服L. reuteri I5007（1.2×10¹⁰ CFU/头/日）,能有效促进仔猪肠绒毛发育,提高空肠二糖酶活性,促进仔猪肠上皮细胞TJ蛋白的表达,在改善新生仔猪的肠黏膜屏障功能中可能起到一定的作用。     

单色光对肉雏鸡小肠黏膜形态结构的影响

 【目的】研究单色光对肉雏鸡小肠黏膜形态结构的影响,为阐明单色光影响肉雏鸡生长发育的作用机理提供形态学依据。【方法】采用LED（Light-emitting diodes）灯作为光源,选用刚出壳AA肉公雏120羽,随机分为4组,分别提供红（660 nm）、绿（560 nm）、蓝（480 nm）和白（400～700 nm）4种光源,每个处理设6个重复,每个重复5只,人工光照光强度均为15 lx,光照时间23 h,试验期7 d;分别于0、7 d时每个重复随机选取1只,利用组织化学染色方法及免疫组织化学方法检测肉鸡十二指肠、空肠、回肠的黏膜结构变化、杯状细胞数量以及空肠肠腺上皮细胞的增殖细胞核抗原（PCNA）的表达。【结果】7日龄时,绿光组各项检测指标比其它光色组明显增高,与红光组相比,绿光组能够促进雏鸡空肠肠腺上皮细胞的增殖（115.5%,P＜0.05）,提高十二指肠、空肠和回肠绒毛上皮的杯状细胞数量（分别为71.8%,35.8%和27.2%,P＜0.05）,增加十二指肠、空肠和回肠绒毛高度（分别为207.9,93.9和63.9 μm,P＜0.05）,黏膜厚度（分别为262.2,184.6和185.6 μm,P＜0.05）以及绒毛高度/隐窝深度比值（分别为18.9%,54.5%和77.8%,P＜0.05）。【结论】在15 lx光强度下,肉鸡生长早期（0～7 d）选用绿光照明,可不同程度地改善肉鸡小肠黏膜结构,提高小肠对营养物质的吸收能力,从而促进肉鸡生长发育。     

谷氨酰胺对肉仔鸡小肠发育及吸收功能的影响

240只1日龄艾维茵肉仔鸡,随机分为4组,1组为对照组,2～4组为试验组,各组分别在基础日粮中添加0、0.2%、0.4%及0.8%的谷氨酰胺(Gln),研究Gln对肉鸡小肠发育、结构及吸收功能的影响。结果表明,饲料中添加Gln可明显提高肉鸡小肠的长度、重量及指数,2周龄时高剂量组(0.8%)效果较好,3、4周龄时则低剂量组(0.2%)较好,其中,空肠受日粮Gln影响最大,回肠次之,十二指肠最小;对肠道形态、结构的组织学观察发现,日粮中添加0.2%的Gln可显著提高试验期间空肠绒毛的高度,降低绒毛的宽度和固有膜厚度;以D-木糖吸收率为代表的小肠主动吸收功能试验表明,试验组肉鸡血清木糖浓度均高于同期对照组肉鸡。上述结果显示,外源性Gln作为肠粘膜细胞的能量来源,对促进小肠发育、维持小肠粘膜的完整性以及提高小肠的主动吸收功能有着重要作用。     

仔银狐小肠绒毛发育研究

本试验从同一养殖场选择发育正常、健康的1d、7d、14d、21d、28d、35d和42d的仔银狐各4只（公、母各半）,通过测量银狐十二指肠、空肠和回肠的肠绒毛高度、宽度、密度,观察不同日龄各段小肠的肠绒毛发育。结果表明：1～21日龄仔银狐各段小肠的肠绒毛高度随着日龄增加呈增加趋势,而小肠绒毛宽度没有明显的变化;28日龄以后小肠的绒毛长度和宽度均有显著的增长;42日龄时达到最高值。仔银狐十二指肠绒毛密度随着日龄的增加而降低,空肠和回肠绒毛密度则在14日龄达到最大,然后随日龄增加而减少。     

Effects of selenium source and level on growth performance,antioxidative ability and meat quality of broilers

This experiment was conducted to investigate the effects of selenium(Se) source and level on growth performance, carcass traits, antioxidative ability and meat quality of broilers. A total of 320 one-d-old Arbor Acres commercial broilers were randomly assigned to 1 of 5 treatments with 8 replicates in a completely randomized design involving a 2×2 factorial arrangement of treatments plus one Se-unsupplemented basal diet control for 42 d. The two Se sources were sodium selenite and Se yeast, and the two supplemental Se levels were 0.20 and 0.40 mg Se kg–1. The results showed that broilers fed the Se-supplemented diets had higher(P0.05) average daily gain and average daily feed intake from 22 to 42 d of age, eviscerated yield and abdominal fat percentages, Se concentrations and glutathione peroxidase(GSH-Px) activities in breast and thigh muscles on d 42, and lower(P0.05) feed/gain from 1 to 21 and 22 to 42 d of age, mortality from 22 to 42 d of age and malondialdehyde(MDA) concentration in thigh muscle on d 42 than those fed the control diet. Broilers fed the diets supplemented with Se yeast had higher(P0.05) p H value and lower(P0.05) shear force in thigh muscle than those fed the diets supplemented with sodium selenite. Additionally, broilers fed the diets supplemented with 0.40 mg Se kg–1 had lower(P0.05) shear force in thigh muscle and higher(P0.05) GSH-Px activities in breast and thigh muscles than those fed the diets supplemented with 0.20 mg Se kg–1. Furthermore, broilers fed the diet supplemented with Se yeast at 0.40 mg Se kg–1 had higher(P0.05) Se concentrations in breast and thigh muscles than those fed the diet supplemented with Se yeast at 0.20 mg Se kg–1, but no differences(P0.05) were observed in these indices of broilers fed the diets supplemented with sodium selenite between 0.20 and 0.40 mg Se kg–1. The results from the present study indicated that supplemental Se could increase the growth performance, muscle Se concentration and antioxidative ability of broilers; and the Se from Se yeast was more effective than the Se from sodium selenite in improving meat quality of broilers.     

发酵棉籽粕膳食纤维对黄羽肉鸡生长性能、屠宰性能及肠道形态的影响

【目的】研究在黄羽肉鸡日粮中添加发酵棉籽粕膳食纤维(fermented cotton meal fiber, FCMF)对其生长性能、屠宰性能和肠道形态的影响。【方法】取120只1日龄健康黄羽肉鸡,随机分成两组,即对照组(CON组)和试验组(FCMF组),分别饲喂添加1.2%未发酵棉籽粕膳食纤维和1.2%发酵棉籽粕膳食纤维的日粮,每组6个重复,每个重复10只鸡,分栏笼养。【结果】各阶段两组的肉鸡生长性能无显著差异(P>0.05)。在35日龄时,FCMF组半净膛率极显著高于CON组(P<0.01),全净膛率提高了3.63%(P<0.05)。在35日龄时,FCMF组的十二指肠绒隐比(VH/CD)显著提高,回肠绒毛高度(VH)与CON组相比差异显著(P<0.05),十二指肠绒毛高度(VH)与CON组相比差异极显著(P<0.01)。在56日龄时,FCMF组的回肠VH化差异极显著(P<0.01)。【结论】日粮中添加FCMF可以提高黄羽肉鸡的全净膛率和半净膛率、十二指肠和回肠绒毛高度以及十二指肠绒隐比及回肠绒毛高度,具有改善黄羽肉鸡屠宰性能和促进肠道发育的作用。     

丁酸梭菌和枯草芽孢杆菌对鸭肠道发育的影响

为研究饲粮中添加丁酸梭菌和枯草芽孢杆菌对育雏育成期高邮鸭肠道发育以及肠道组织形态、杯状细胞密度等的影响,选择1日龄体重相近的健康高邮鸭90只,随机分3组,每组3个重复,每个重复10只。对照组饲喂基础全价日粮,丁酸梭菌组添加丁酸梭菌活菌3×10⁵ CFU·g^-1,枯草芽孢杆菌组添加枯草芽孢杆菌活菌5×108 CFU·g-1,试验期60 d。结果表明,高邮鸭日粮中添加丁酸梭菌和枯草芽孢杆菌显著提高60日龄高邮鸭十二指肠、空肠和回肠重量(P <0.05),显著增加空肠长度(P <0.05)。丁酸梭菌添加组显著降低空肠和回肠的隐窝深度(P <0.05),显著增加回肠的黏膜厚度、肌层厚度和绒毛高度(P <0.05)。丁酸梭菌和枯草芽孢杆菌添加后提高高邮鸭十二指肠、空肠、回肠和盲肠杯状细胞密度(P <0.05);与对照组相比,丁酸梭菌添加组中十二指肠,空肠组织黏糖蛋白2编码基因MUC2m RNA表达量显著提高(P <0.05)。综上所述,高邮鸭自1日龄起日粮中添加丁酸梭菌和枯草芽孢杆菌后,改善其肠道显微结构,在全价日粮...     

Effects of Cultivar on Phenolic Content and Antioxidant Activity of Naked Oat in China

To evaluate the effects of naked oat cultivars on their phenolic contents and antioxidant activities, the oat seeds from 21 different cultivars in China were collected, and their major nutritional components, compositions of polyphenols, and antioxidant activities were measured. As the results, oat cultivars affected its phenolic composition and antioxidant activity significantly. Vanillin, chlorogenic acid, ferulic acid, avenanthramide C（Bc）, avenanthramide A（Bp）, and avenanthramide B（Bf） in oat polyphenols extracts were detected in all cultivars of oat, while caffeic acid, p-coumaric acid and rutin were partly detected. All oat cultivars showed significant free radical scavenging activity, although their activities were lower than that of vitamin C（VC）. Different oat varieties showed different antioxidant activities, among which Yanke 1 had the best ability to scavenge ·OH（（58.78±1.99） μg mL-1）, Baiyan 10 showed the strongest DPPH·（（22.00±0.43） μg mL-1） and ABTS·＋（（6.92±0.44） μg mL-1） scavenging activity, and Dingyou 1 showed good scavenging ability of DPPH·（（22.71±0.42） μg mL-1） and ·OH（（81.50±1.73） μg mL-1）. In addition, the correlation coefficients of contents between the major nutritional components in different cultivars of oat and phenolic compounds indicated that determination of main nutrients could be used as an easy technique to evaluate approximately the contents and compositions of oat polyphenols, which simplifies the selection of good oat cultivar.     

2-甲基丁酸对犊牛小肠酶活及葡萄糖转运载体基因表达的影响

【目的】断奶前后犊牛胃肠发育及其吸收与代谢功能会发生明显改变,尤其是断奶前的饲养管理显著影响犊牛胃肠的发育乃至以后的生产性能。2-甲基丁酸是一种短链支链挥发性脂肪酸,在瘤胃内主要来自于支链氨基酸的降解,可以作为反刍动物胃肠发育的调控剂。因此,通过研究2-甲基丁酸对断奶前后犊牛小肠消化酶活性、小肠黏膜生长激素受体和钠-葡萄糖共转运载体m RNA表达的影响,揭示2-甲基丁酸对犊牛小肠发育的作用机理。【方法】试验选用32头体重(44.7±0.3)kg、发育正常的15日龄哺乳荷斯坦公犊,随机分为4组,每组8头,对照组饲喂基础日粮,试验组分别在基础日粮基础上添加2-甲基丁酸3、6和9 g·d~(-1)。所有犊牛在45日龄断奶,分别于断奶前(30日龄)和断奶后(90日龄)从各组抽取4头,晨饲前称重后进行屠宰,采集十二指肠、空肠近端1/4处、空肠远端1/4处和回肠末端的内容物,采用比色法测定乳糖酶、淀粉酶、脂肪酶和胰蛋白酶的活性,采集十二指肠、空肠近端1/4处、空肠远端1/4处和回肠末端黏膜组织,采用实时荧光定量PCR技术检测小肠黏膜组织生长激素受体(GHR)和钠-葡萄糖共转运载体(SGLT~(-1))m RNA的表达。【结果】断奶后犊牛小肠各段乳糖酶活性显著低于断奶前,而断奶后犊牛小肠各段淀粉酶、脂肪酶和胰蛋白酶活性却显著高于断奶前。日粮添加2-甲基丁酸6和9 g·d~(-1)后,较3 g·d~(-1)和对照组显著提高断奶前犊牛空肠近端、空场远端和回肠乳糖酶活性(P0.05),较3 g·d~(-1)和对照组显著提高断奶后犊牛十二指肠和回肠乳糖酶活性,较3 g·d~(-1)的2-甲基丁酸和对照组显著提高了断奶前后犊牛小肠各段脂肪酶、胰蛋白酶活性(P0.05)。断奶后犊牛小肠各段黏膜GHR和SGLT~(-1)m RNA的表达均显著低于断奶前。日粮添加2-甲基丁酸6和9 g·d~(-1)后,较3 g·d~(-1)的2-甲基丁酸和对照组显著提高了断奶前后犊牛小肠各段黏膜GHR m RNA的表达(P0.05),较对照组显著提高了断奶前后犊牛十二指肠黏膜SGLT~(-1)m RNA的表达(P0.05),较3 g·d~(-1)和对照组显著提高了断奶前后犊牛空肠近端、空肠远端和回肠黏膜SGLT~(-1) m RNA的表达。【结论】结果提示,断奶前后犊牛日粮添加2-甲基丁酸能够增加小肠消化酶活性及小肠黏膜生长激素受体和钠-葡萄糖共转运载体m RNA的表达,综合以上指标分析,建议断奶前后犊牛日粮中2-甲基丁酸的最适添加量为6 g·d~(-1)。     

乳酸对仔猪消化酶发育的影响

为了研究乳酸对断奶仔猪消化酶发育的影响,采用144头刚断奶的杜大长商品仔猪,随机分为对照组（基础饲粮）、基础+3 g·kg-1乳酸酸化剂组和基础+6g·kg-1乳酸酸化剂组,试验为期28 d。分别在试验第7,14和28天,每组屠宰9头试验猪,分别取胃和十二指肠内容物、取十二指肠和空肠用于组织切片,用无菌玻片刮取小肠黏膜用于测定黏膜酶活。测定了添加乳酸对饲料pH和缓冲值、仔猪胃和十二指肠内pH、胃内容物胃蛋白酶活性、小肠内容物胰蛋白酶活性和二糖酶活性、小肠绒毛高度和黏膜二糖酶活性。结果表明：添加乳酸降低了饲料和胃内 pH,显著提高仔猪胃内容物胃蛋白酶活性;提高小肠内容物胰蛋白酶和二糖酶活性;提高十二指肠和空肠绒毛高度,提高了小肠黏膜二糖酶的活性。结果表明,添加乳酸能促进仔猪消化酶的发育,并通过胃和小肠多个环节的作用,提高仔猪对饲料营养物质的消化能力,从而促进仔猪的生长。     

Antimicrobial Susceptibility and Characterization of Outer Membrane Proteins of Aeromonas hydrophila Isolated in China

Aeromonas hydrophila isolates from clinical cases （n=43） were tested against 8 antimicrobial agents and typed by outer membrane protein （OMP） pattern by using sodium dodecyl sulfate gel electrophoresis. All isolates were resistant to ampicillin （MICs, ≥16 μg mL-1） and sulfamonomethoxine （MICs≥64 μg mLl）, but susceptible to norfloxacin （MICs,≤0.5 μg mL-1）. There was a high incidence of resistance to erythromycin （90.70%） and tylosin （93.02%）, while a low incidences of resistance to ciprofloxacin （2.33%）, enrofloxacin （2.33%） and florfenicol （4.65%）. Six different outer membrane protein patterns were found among 34 isolates by analyzing proteins in the range of 22 to 50 kDa, other than 9 isolates with their respective profiles. The strains with the similar OMP profiles had similar resistances. Compared with the other strains from the same OMP patterns, NB-1, A.Pun and MR-1 had lacked the proteins in the range of 30 to 45 kDa and their resistance to florfenicol substantially increased. It is speculated that the outer membrane protein changes might correlate with decreased susceptibility to florfenicol in the three strains. Some strains which showed completely identical OMP types had a little difference in their resistance to fluoroquinolones, indicating that there might be other factors that were involved in the antimicrobial resistance of A. hydrophila.     

Exploiting push-pull strategy to combat the tea green leafhopper based on volatiles of Lavandula angustifolia and Flemingia macrophylla

Thirteen volatile compounds were identified from Flemingia macrophylla plants. Eight major components significantly attracted the tea green leafhoppers, Empoasca flavescens F. Based on their relative abundances, following synthetic blends were made for field experiments: 1) eight-component-attractant blend included Z-3-hexen-1-ol, Z-3-hexenyl acetate, Z-ocimene, Me SA, Z-3-hexenyl butyrate, dodecane, hexadecane and nonanal at 10, 10, 1, 11, 2, 6, 2 and 4 mg mL~(-1) in n-hexane, respectively; 2) four-component-attractant blend #1 contained hexadecane, Z-3-hexenyl acetate, Z-3-hexen-1-ol and nonanal at 2, 10, 10 and 4 mg mL~(-1) in n-hexane, respectively; 3) four-component-attractant blend #2 contained hexadecane, Z-3-hexenyl acetate, Z-3-hexen-1-ol and Me SA at 2, 10, 10 and 11 mg mL~(-1) in n-hexane, respectively. Thymol and 1-methoxy-4-methyl-2-(1-methylethyl)-benzene, identified from Lavandula angustifolia aeration samples, significantly repelled the leafhopper as strong repellents when tested alone or in combination at 10 mg mL~(-1). For field bioassays, each attractant lure was attached to a bud green sticky board hung from a bamboo stick at above tea plant level for catching the leafhoppers, whereas the repellent dispenser was tied to a tea branch inside tea clump for pushing the leafhoppers away from tea clumps. The results showed that the eight-component-attractant blend caught similar numbers of the leafhopper as did the four-component-attractant blend #1 at about 53–79 leafhoppers/trap/day, which were significantly higher than those on the hexane-control bud green sticky boards. Average leafhopper catches from un-baited sticky boards were about 51–73 leafhoppers/trap/day when pushed by the repellents placed inside tea plants, with the two-component-repellent blend being more effective than their single components. When the two-component-repellent blend was further tested with the three attractant blends in a push-pull fashion, average trap catches ranged from 62 to 92 leafhoppers/trap/day. Control efficacy on the leafhoppers within the push-pull zones increased progressively from day 1(43%) to day 5(73%). This push-pull approach might have a great potential as a green control strategy for combating the tea green leafhoppers.     

非淀粉多糖酶对肉鸡肠道消化酶的影响

 将200只21日龄罗斯肉鸡分5个处理组：处理组1（正对照组）、处理组2（负对照组）,处理组3～5在负对照组日粮基础上各添加一种非淀粉多糖酶制剂。肉鸡饲养至42日龄屠宰,测定肠道及内容物消化酶。结果显示：负对照组肉鸡十二指肠和空肠及其内容物的淀粉酶和蛋白酶活性显著小于（P ≤005）正对照组。处理组3肉鸡十二指肠及其内容物的淀粉酶和蛋白酶活性显著大于负对照组,与正对照组相近（P>005）。处理组3肉鸡空肠内容物的淀粉酶、蛋白酶和脂肪酶活性显著大于其他4个处理组。处理组4和5肉鸡的十二指肠及内容物的淀粉酶活和蛋白酶活性差异不显著,但显著低于处理组3。处理组4肉鸡空肠蛋白酶活性与处理组3差异不显著,但显著大于处理组5。以上结果说明,选用NSP酶制剂应实测产品的酶类和酶活性,以合理有效使用。     

Effects of Acute and Chronic Cold Stress on Antioxidant Function in Intestinal Tracts of Chickens

This study was to investigate the effects of cold stress on the contents of total antioxidant capacity (T-AOC), malondialdehyde (MDA) and superoxide dismutase (SOD) in duodenum, jejunum and ileum of chickens. A total of 80 15-day-old male chickens were treated by cold stress with the duration of the acute cold stress being 1, 3, 6, 12, and 24 h, and the chronic cold stress was 5, 10, and 20 days, respectively. Cold stress temperature was (12±1)℃. The chemical colorimetric method was used to detect the changes of the T-AOC, SOD activities and MDA contents. The results showed that compared with the corresponding control group, effects of acute cold stress on the T-AOC in duodenum, jejunum and ileum of chickens significantly (P0.05) increased firstly and then decreased. Under chronic cold stress, the T-AOC significantly (P0.05) decreased. Under acute cold stress and chronic cold stress, the MDA contents significantly (P0.05) increased in duodenum, jejunum and ileum of chickens. The effects of acute cold stress on the SOD activities in duodenum, jejunum and ileum of chickens significantly (P0.05) increased firstly and then decreased. Under chronic cold stress the SOD activities significantly (P0.05) decreased in jejunum and ileum, but significantly (P0.05) decreased firstly and then increased in duodenum.     

Effects of Tebufenozide on the Biological Characteristics of Beet Armyworm （Spodoptera exigua Hǖbner） and Its Resistance Selection

In this article, the selection of tebufenozide to beet armyworm （Spodoptera exigua Htibner） was studied by the treatments to alternative generations＇ 3rd-instar larvae with LC50 dose and to continuous generations＇ larvae with LC10 dose; the effects of tebufenozide on the biological characteristics of current and subsequent generations were examined by the treatments to 3rd-instar larvae and egg pods in different concentrations. After treatments with LC50 dose till F11, the toxicity of tebufenozide to beet armyworm had no significant change, whereas the pupation rate, pupal weight, and fecundity were reduced markedly. After treatments with LC10 dose till Fl9, the beet armyworm only developed 3.52-fold resistance, and the main biological characteristics were nearly accordant in each generation. The livability was reduced 72 h later after treatments to 3rd-instar larvae, respectively in 2.5-40 μg mL^-1, and larval duration, pupation rate, and pupal weight changed considerably with the increase in concentrations. The fecundity, larval livability, larval weight and pupal weight of subsequent generations were reduced as the dose increased over 10 μg mL^-1. The hatching rate of egg pods did not differ with that of the controls obviously after treatment in 10-300 μg mL^-1. But the larval livability, larval weight and pupal weight were reduced when eggs were exposed to 50 μg mL^-1 dose or more. The results indicated that tebufenozide had low resistance risk to the current and subsequent generations of beet armyworm even if tebufenozide had significant effects on the biological characteristics of this insect.     

树舌发酵浸膏多糖对肉鸡肠黏膜组织结构及肠道免疫细胞的影响

为研究肉鸡日粮中添加树舌发酵浸膏多糖(Polysaccharides from the fermentation concentrate of Ganoderma applanatum(Pers.ex Gray.),GAP)对肉鸡肠黏膜结构及上皮内淋巴细胞和杯状细胞数量的影响,选用1日龄健康AA肉鸡225只,随机分成5个处理组,每组3次重复,每次重复15只。5个处理组分别为空白对照组(基础日粮)、抗生素阳性对照组(基础日粮+5mg/kg黄霉素)和3个GAP组(基础日粮中分别添加0.05%、0.10%和0.20%GAP),试验期42d。结果表明:1)与对照组相比,日粮中添加0.10%和0.20%的GAP可显著增加肉鸡肠绒毛高度(P0.05),降低隐窝深度(P0.05),提高肠绒毛高度和隐窝深度的比值(V/C)(P0.05);2)与对照组相比,日粮中添加0.10%和0.20%GAP显著升高小肠各段的上皮内淋巴细胞和杯状细胞数量(P0.05);3)小肠各段上皮内淋巴细胞和杯状细胞数量随年龄增长而逐渐增多;4)同一日龄各试验组的上皮内淋巴细胞数量从十二指肠到回肠递减,而杯状细胞则呈递增趋势。以上结果提示:在肉鸡日粮中添加GAP可显著改善肉鸡小肠黏膜结构,维持肠道黏膜的正常屏障结构,促进肉鸡健康生长。其中以0.10%GAP添加量效果最好。     

Effect of dietary supplementation of pyrroloquinoline quinone disodium on growth performance,meat quality and antioxidative ability of broilers

This study was conducted to investigate the effect of dietary supplementation with pyrroloquinoline quinone(PQQ) in the form of PQQ disodium(PQQ·Na2) on the growth performance, carcass traits, meat quality and antioxidative ability of broilers. A total of 720 one-d-old Arbor Acres male broilers were randomly allocated to 1 of 6 treatments with 8 replicates of 15 birds per replicate in a completely randomized design. Birds were fed a PQQ·Na2-unsupplemented corn-soybean meal basal diet(control) or the basal diet supplemented with 0.1, 0.2, 0.3, 0.4 or 0.5 mg PQQ·Na2 kg–1 for 42 d. Compared with the control chicks, the chicks fed the diets supplemented with PQQ·Na2 had lower(P0.05) feed:gain(F/G) during the grower phase and drip losses of breast muscles on day 42. As supplemental PQQ·Na2 level increased, plasma total antioxidant capacity(T-AOC) on d 42, liver T-AOC on d 21 and heart T-AOC on d 21 and 42 increased linearly(P0.05), but malondialdehyde concentrations in plasma, liver and heart on d 21 or 42 decreased linearly(P0.001) or quadratically(P0.005). The results from the present study indicate that dietary supplemental PQQ·Na2 can improve antioxidant ability and meat quality of broilers, and in general, it is implied that the optimal supplemental PQQ·Na2 level is 0.1 mg kg–1 of diet for broilers from 1 to 42 d of age.     

Effects of Dietary Isoflavone Supplementation on Meat Quality and Oxidative Stability During Storage in Lingnan Yellow Broilers

To investigate the effects of a synthetic isoflavone （SI） on meat quality and oxidative stability, 1 500 43-d-old Lingnan yellow male broilers were randomly assigned to five dietary treatments： diets supplemented with 0, 10, 20, 40, or 80 mg SI kg-1, fed ad libitum for a period of 3 wk. After refrigerated storage, a＊ value of the meat increased with dietary SI supplementation using 10 and 40 mg kg-1 level （P〈0.05）, L＊ value decreased （P〈0.05）, and 40 mg kg-j increased the pH （P〈0.05）. Supplementation with SI, at all levels, increased water holding capacity （P〈0.05） and decreased lactic acid content of meat （P〈0.05）. The concentration of malondialdehyde at 72 h decreased linearly （P=0.005） and quadratically （P=0.004） with increasing levels of SI. Dietary SI at 20 and 40 mg kg-1 levels enhanced total superoxide dismutase activity in meat （P〈0.05）. Meat pH quadratically decreased as the storage time increased （P〈0.05）, with the highest value at 24 h （P〈0.05）. Lactic acid and malondialdehyde concentrations of meat increased over time, with value at 96 h being far higher than at earlier times （P〈0.05）. Supplemental SI linearly and quadratically increased the mRNA abundance ofglutathione peroxidase （GPX） （P=0.001 and P=0.002） and catalase （CAT） （P=0.003 and P=0.006） in breast muscle. The results from this study indicate that dietary supplementation with SI can improve meat quality during refrigerated storage by decreasing lipid peroxidation and enhancing oxidative stability and, for male broilers from 43 to 63 d of age, the optimal level of SI was 40 mg kg-1.     

肉鸡肠道CDX2 mRNA表达的肠段差异性与发育性变化

选用遗传背景相同的1日龄父母代雄性Arbor Acre(AA)肉雏鸡120羽,随机分为4个重复,采用相对定量RT-PCR方法,以从肉鸡30 d肠道样品为模板,研究肉鸡肠道尾形相关同源盒基因(cadua-related type homeoboxgene)家族中CDX2 mRNA表达的组织特异性;以从肉鸡十二指肠和空肠样品为模板,研究肉鸡肠道CDX2 mBNA表达的发育性变化.结果显示:AA肉鸡十二指肠CDX2 mRNA的表达丰度高于空肠(P=0.09)、回肠(P=0.06)和结直肠(P=0.05);从肉鸡CDX2 mRNA在十二指肠及空肠中的表达具有相同的发育模式,2～30 d下降,44 d回升,58 d略微下降;在2和44 d时的表达丰度显著高于30 d(P<0.05).以上结果表明:从肉鸡肠道近端CDX2mRNA的表达丰度高于远端(P>0.05).AA肉鸡十二指肠及空肠CDX2 mRNA的表达具有相同的发育模式,表明CDX2 mKNA表达受到发育阶段的调控,且在十二指肠和空肠间具有稳定性.     

代乳粉对早期断奶沂蒙黑山羊羔小肠发育、菌群多样性及葡萄糖转运载体基因表达的影响

【目的】研究饲喂代乳粉对早期断奶沂蒙黑山羊羔小肠发育、菌群多样性及葡萄糖转运载体基因表达的影响,为沂蒙黑山羊早期断奶羔羊的培育提供理论依据。【方法】将36只双胎沂蒙黑山羊羔羊分成2组,每组6个重复,每个重复3只。其中,对照组(Ⅰ组)羔羊随母哺乳至75日龄,试验组(Ⅱ组)于10日龄断奶后饲喂代乳粉。分别于试验的第10、15、25、45和75 天称羔羊活体重以及屠宰后十二指肠、空肠、回肠重量,并收集各肠段内容物、黏膜组织样品。采用16S rDNA的PCR-DGGE技术和实时荧光定量PCR等方法,分析小肠菌群定植规律及葡萄糖转运载体(SGLT-1、GLUT-2)基因mRNA表达量。【结果】Ⅱ组羔羊45 d时平均日增重和空肠、回肠重量显著高于Ⅰ组(P＜0.05),而75 d时平均日增重和回肠重量极显著高于Ⅰ组(P＜0.01)。十二指肠在45和75 d、空肠在15 d及回肠在10 d时两组间菌群变化较为明显,二者菌群多样性指数回肠最高,其次空肠、十二指肠;两组各肠段优势菌群均为溶淀粉乳杆菌和普雷沃氏菌属,但随着日龄增加,Ⅰ组各肠段益生菌属总细菌数量呈下降趋势,Ⅱ组却与此相反。Ⅱ组在10 d时SGLT-1和GLUT-2基因mRNA表达量最低,而25 d后Ⅱ组表达量均高于Ⅰ组,且差异不显著(P＞0.05);上述基因表达量呈现肠段部位间差异,其中SGLT-1基因mRNA表达量变化空肠最大,十二指肠最低,而GLUT-2基因mRNA表达量变化十二指肠最大,回肠最低。【结论】饲喂代乳粉在第25 天时可促进沂蒙黑山羊早期断奶羔羊空肠、回肠有益菌提前定植,并通过调控葡萄糖转运载体基因表达而引起葡萄糖吸收转运的改变,进而影响羔羊后期肠道组织及机体的生长发育。