蛋鸡日粮中添加苜蓿草粉对肠道菌群的影响研究

为研究蛋鸡日粮中添加苜蓿草粉对肠道菌群结构及多样性造成的影响,试验选用17周龄海兰灰商品代蛋鸡90羽,随机分为2组,每组45羽,设空白对照组和苜蓿草粉添加组,对盲肠内容物进行菌群培养计数和PCR-DGGE。结果显示：苜蓿草粉组盲肠大肠杆菌和乳酸杆菌数目均高于对照组,但差异不显著（P〉0.05）。对照组DGGE泳道条带数目高于草粉组,二组共有条带比例为36.4%。对照组各样本之间聚类较近,苜蓿草粉组样本与其聚类距离较远。试验表明,日粮中添加苜蓿草粉后,蛋鸡肠道的菌群结构及多样性均发生了变异。     

饲料添加山姜和蜡样芽孢杆菌对小鼠肠道菌群的影响

滑叶山姜(Alpinia tonkinensis Gagnep)为姜科山姜属植物,分布于我国广西和云南地区。以其果实或根茎入药,含有挥发油、黄酮类化合物等多种     

替米考星对内毒素炎症小鼠存活率和细胞因子的影响

替米考星按20 mg/kg剂量经灌胃给药后,观察其对内毒素(LPS)炎症小鼠的保护率,并通过不同时间段眼球采血,分离血清,应用试剂盒用酶联免疫吸附分析(Enzyme-linked immunosorbent assy,ELISA)法测定小鼠血清中肿瘤坏死因子-α(TNF-α)、白细胞介素-10(IL-10)、白细胞介素-6(IL-6)、白细胞介素-1(IL-1β)的水平.结果表明,替米考星明显提高了内毒素炎症小鼠的存活率,死亡率由100%降低为50%(P<0.05).LPS(20 mg/kg)能提高血清中TNF-α、IL-10、IL-6和IL-1β的水平,替米考星能够显著抑制TNF-α、IL-6和IL-1β的释放,而明显提高IL-10的水平.     

二甲酸钾预防沙门菌感染小鼠的效果评价及对肠道菌群的影响

二甲酸钾(potassium diformate, KDF)为酸化剂的代表之一,在2001年被欧盟批准可作为饲料添加剂使用,在2005年被我国批准作为饲料添加剂。目前已有较多的研究表明KDF可以显著提高动物的生长性能,然而关于KDF对传染病预防作用的直接证据的研究还比较少。本研究旨在通过体外抑菌试验及小鼠感染模型,在体外和体内评价KDF对致病菌的预防效果,并检测KDF对小鼠肠道菌群的影响,以探讨KDF的作用机理。在体外检测KDF对养殖场中常见病原菌的最低抑菌浓度(minimum inhibitory concentration, MIC)后,选取3～4周龄,体重12～15 g的C57/BL6雌鼠,分组饲喂一周后感染鼠伤寒沙门菌,记录KDF饲喂组、KDF饮水组和对照组小鼠感染后的体重变化(n=6),并在感染后第6天将小鼠安乐死检测其盲肠组织载菌量(n=6)、血清炎性细胞因子水平(n=6)和盲肠病理变化(n=3)。另外选取两组3～4周龄,体重12～15 g的C57/BL6雌鼠(n=5),饲喂含有KDF的饲料两周后采集其粪便,利用16S rRNA测序技术分析饲喂KDF对小鼠盲肠菌群的影响。结...     

葡萄糖氧化酶对饲喂含霉变饲料小鼠体重和肠道微生物的影响

本试验旨在研究葡萄糖氧化酶(GOD)缓解霉变饲料对小鼠平均日增重和肠道菌群变化的影响。18~22 g昆明小鼠130只,随机分为13组。分别饲喂添加0、10%、20%、30%霉变玉米面和0、0.1%、0.3%、0.5%GOD的饲料,试验期为60 d。结果表明:1)不同霉变玉米添加量的饲料饲喂小鼠60 d,与试验对照组比较,0.3%GOD能显著或极显著改善小鼠平均日增重(P<0.05或P<0.01)。2)添加10%霉变玉米面,0.3%和0.5%GOD组与试验对照组比较,极显著降低了大肠杆菌的数量(P<0.01),增加了乳酸杆菌数量(P<0.01);添加20%霉变玉米面,饲喂60 d时,3种不同浓度的GOD极显著降低了大肠杆菌数量(P<0.01),提高了乳酸杆菌数量(P<0.01);添加30%霉变玉米面,3种不同浓度的GOD显著或极显著减少了肠道大肠杆菌数量(P<0.05或P<0.01),0.3%GOD效果较好,饲喂60 d时,0.3%和0.5%的GOD添加量极显著提高了肠道乳酸杆菌数量(P<0.01)。结果提示,GOD能够缓解霉变饲料对小鼠生长造成的影响。饲料中黄曲霉毒素B1含量低于67.77μg/kg时,添加0.3%的GOD效果较好。     

EM菌对小鼠肠道病变的修复作用

本研究以小鼠肠道为模型,采用葡聚糖硫酸钠(DSS)诱导小鼠肠道病变,并用EM菌修复小鼠肠道,探索EM菌对小鼠肠道病变的修复作用。试验结果表明,在使用DSS建立病变模型后,对照组小鼠停药后病情依然持续加重,很快死亡;而喂食EM菌处理组,小鼠的体重逐步恢复、免疫酶活力几乎恢复正常、肠道内壁结构也与正常小鼠相似,小鼠死亡率大大降低。说明EM菌在肠道病变的修复方面具有显著作用。     

外源MDR鼠伤寒沙门菌对健康小鼠肠道菌群的影响

旨在探究外源多重耐药(multidrug resistant, MDR)鼠伤寒沙门菌进入健康小鼠肠道后对其肠道菌群的影响。将25只小鼠随机分为质控组(C)、灌胃1 d组(G1)、灌胃3 d组(G2)、灌胃5 d组(G3)和灌胃7 d组(G4),每组5只。将携带耐药基因的猪源耐药鼠伤寒沙门菌按10⁶ CFU·mL^-1的浓度对除质控组外的试验组小鼠进行灌胃。分别采集灌胃前第0天和灌胃结束后1～14 d的新鲜粪便样本,采用高通量测序技术分析灌胃后小鼠粪便中肠道菌群多样性变化。结果显示：1)与C组比较,各试验组在灌胃结束后临床上均表现为轻微腹泻,从粪便样本中分离出与灌胃菌同一型的MDR鼠伤寒沙门菌,且分离率差异不大;2)试验组小鼠肠道菌群Alpha多样性中Chao1、Goods＿coverage和Observed＿species指数明显高于C组;3)G2组、G3组和G4组在门及属水平物种丰度上变形菌门(Epsilonbacteraeota)和螺杆菌属(Helicobacteraceae)相对丰度显著低于C组(P<0.05)。在LEfSe分析上变...     

叶下珠醇提物对肠炎沙门菌毒素致小鼠炎症的影响

研究叶下珠醇提物对攻毒肠炎沙门菌(Salmonella enteritidis)毒素小鼠血清、肝、脾和空肠炎症因子水平的影响。将50只昆明小鼠随机分为空白对照组(CK)、肠炎沙门菌毒素组、叶下珠醇提物高剂量组、中剂量组和低剂量组(40 mg/mL、20 mg/mL和10 mg/mL)。各组灌胃叶下珠醇提物7 d,除对照组外,其余各组均腹腔注射肠炎沙门菌毒素,24 h后采血,扑杀各组小鼠,快速分离肝、脾和空肠组织,ELISA测定小鼠血清中IL-6、TNF-α和IL^-10水平。结果表明,与对照组相比,肠炎沙门菌毒素组小鼠腹泻等临床症状明显,剖检可见肝、脾、肠出血肿胀等病变,叶下珠醇提物各剂量组小鼠临床症状和脏器损伤均明显轻于肠炎沙门菌毒素组。炎症因子检测结果显示,与对照组相比,肠炎沙门菌毒素组血清中IL-6水平显著下降(P<0.05),但TNF-α和IL^-10水平变化不显著(P>0.05),肝、脾和空肠中IL-6、TNF-α水平均极显著升高(P<0.01),IL^-10水平均极显著降低(P<0.01)。...     

PCV2对小鼠肠道SIgA及相关细胞因子含量的影响

用PCV2感染5周龄昆明系小鼠,分别在感染后7,14,21,28,35,42d处死小鼠,取脾脏、腹股沟淋巴结、Peyers结做PCR鉴定PCV2感染情况,提取肠道中蛋白检测SIgA及肠道相关细胞因子IL-2、IL-4、IL-10和IFN-γ含量的变化。结果显示:随着感染时间的延长,试验组小鼠肠道SIgA、IL-2和IFN-γ水平均呈先升高后降低的趋势,IL-4和IL-10呈持续升高的趋势。结果表明:小鼠肠道SIgA及相关细胞因子的含量在PCV2的刺激下发生了不同程度的改变。     

蝇蛆对家禽肠道疾病的防治作用机理研究

蝇蛆含有丰富的微量元素、维生素和抗菌肽等物质。本文从蝇蛆在家禽肠道菌群的平衡作用、免疫力的提升作用和抗菌肽的抗菌、抗病毒、抗寄生虫活性等方面综述了蝇蛆对家禽肠道疾病防治作用机理的研究概况。     

Digestibility and safety of dry black soldier fly larvae meal and black soldier fly larvae oil in dogs

Two trials were conducted to assess the acceptance, safety and digestibility of diets containing various inclusion levels of partially defatted black soldier fly (Hermetia illucens) larvae (BSFL) meal and BSFL oil by dogs. In trial 1, 5 extruded diets were evaluated for acceptance in adult Beagle dogs (n = 20; 10 male, 10 female) during a 48-hr period. Diets contained graded levels of BSFL meal (5.0%, 10.0%, and 20.0%), or graded levels of BSFL oil (2.5% and 5.0%), and all diets were well accepted. Thus, a digestibility trial (trial 2) was run with 56 adult dogs (16 male, 40 female) allocated into 7 dietary treatments; dogs were offered an extruded control diet containing no BSFL meal or oil, or extruded diets where BSFL meal partially replaced poultry by-product meal and corn meal at dietary levels of 5%, 10%, or 20% inclusion, or diets with BSFL oil partially replacing poultry fat at a 1:1 ratio at levels of 1%, 2.5%, or 5% inclusion. The treatment diets were fed for 28 d, during which time dogs were monitored for health (via physical examinations, clinical observations, and blood chemistry and hematology) and ingredient evaluation (via body weight, feed consumption, stool observation, and fecal nutrient apparent total tract digestibility). There were no significant differences in body weight or food consumption between treatment groups (P > 0.05) and daily observations indicated that the general health of the animals was maintained throughout the study. Stool quality was maintained at 3.2 to 3.4 (on a 5-point scale with a score of 1 being watery diarrhea and a score of 5 being hard, dry, and crumbly) per treatment group over the fecal observation period (days 22 to 27), indicating a well formed, sticky stool. All group mean hematology and blood chemistry parameters remained within normal limits for dogs. Apparent total tract digestibility of dry matter, protein, fat, and calories was not affected by treatment (P > 0.05). In general, amino acid digestibility was not impacted by treatment although some minor changes were observed. Apparent total tract digestibility was high for all nutrients examined. Overall, it was concluded that BSFL meal and BSFL oil are well tolerated by dogs and their consumption results in no impact to physiology that would be concerning. Based on these data, BSFL meal and oil did not affect general health and could be included safely in dog diets.     

黑水虻幼虫替代饲料直接投喂对锦鲤生长消化、肝胰脏抗氧化酶和血清非特异性免疫指标的影响

以锦鲤为试验对象,将黑水虻幼虫活虫和黑水虻幼虫干虫分别替代饲料对锦鲤进行投喂,投喂30 d后测定血清和组织中抗氧化酶活性和非特异性免疫指标。结果表明,干虫组的特定生长率、增重率显著低于对照组和活虫组(P<0.05),而体均重与肥满度各组间差异不显著(P>0.05)。血清中ALT活力活虫组显著高于干虫组(P<0.05),AKP活力对照组显著低于活虫组和干虫组(P<0.05),AST活力、ACP活力和溶菌酶活力各组间差异不显著(P>0.05)。肝胰脏T-SOD活力和T-AOC对照组显著低于活虫组和干虫组(P<0.05),CAT活力和GSH-Px活力各组间差异不显著(P>0.05)。前肠淀粉酶、脂肪酶、胰蛋白酶活力各组间差异不显著(P>0.05)。可见,将黑水虻作为一种环保、价格低廉的饲料投喂锦鲤,对其生长、抗氧化能力和非特异性免疫有促进作用,作为新型饲料具有可行性。     

超高效液相色谱串联飞行时间质谱法检测黑水虻产品中黄曲霉毒素B1

本研究建立了黑水虻产品中黄曲霉毒素B1(AFB1)的超高效液相色谱串联四级杆飞行时间质谱测定方法,对黑水虻幼虫粉中AFB1的提取、超高效液相色谱串联质谱检测条件进行了优化。使用甲醇-水溶液(8:2,体积比),添加7%氯化钠对黑水虻幼虫粉中AFB1进行提取,免疫亲和柱净化,甲醇-乙酸铵(10 mmol/L)水溶液作为流动相进行梯度洗脱,电喷雾离子源(ESI)正离子模式检测,7.0 min出峰。结果表明:AFB1在1~20μg/kg浓度范围内线性关系良好,相关系数大于0.999,幼虫粉回收率为83.1%~118.3%,相对标准偏差(RSD)为6%~10%;虫粪回收率为76.6%~114.1%,相对标准偏差(RSD)为0~3%;检出限(LOD,S/N≥3)为0.01μg/kg,定量限(LOQ,S/N≥10)为0.05μg/kg。该方法操作简单、结果准确,可以用于黑水虻幼虫粉和虫粪产品中AFB1的检测。     

固相萃取-超高压液相色谱串联质谱测定黑水虻幼虫四环素和土霉素残留

四环素类抗生素是畜禽粪便中残留量最高的抗生素之一,黑水虻幼虫转化畜禽粪便有蓄积抗生素的风险,因此监测虫体抗生素的含量以明确其作为蛋白原料的饲用安全性十分必要.本研究建立了超高效液相色谱-串联三重四极杆质谱(UPLC-MS/MS)快速检测黑水虻幼虫体内四环素(TC)和土霉素(OTC)残留的方法.采用乙腈-柠檬酸缓冲液与E...     

中药蒲地散对肉鸡生长性能及肠道功能的影响

试验选用9 000只1日龄的白羽肉鸡,随机分为2组,每组3个重复,每个重复1 500只,其中:蒲地散组饲料中添加中药蒲地散500g/t,对照组饲料不添加任何药物.试验期28 d,于试验第7、14、21、28天采样评估蒲地散对肉鸡生长性能、肠道免疫水平、肠道形态及肠道菌群的影响.结果:与对照组相比,蒲地散组鸡存活率显著提...     

Black soldier fly and yellow mealworm live larvae for broiler chickens: Effects on bird performance and health status

The commercial broiler chicken strains are the result of successful selection programmes. Most of the problems related to welfare arise from the high growth rate and body weight. The use of environmental enrichments in intensive farming could have a positive effect on birds by increasing animal welfare. The aim of the study was to evaluate the effects of Hermetia illucens (HI) and Tenebrio molitor (TM) live larvae in the diets of broiler chickens on growth performance, carcass yield and health status. A total of 180 four-day-old male broiler chickens (Ross 308) were randomly allotted to 18 pens. Each pen was assigned to one of the three dietary treatments (6 replicates/treatment, 10 birds/replicate) as follows: (i) control diet (C): commercial feed (two feeding phases: starter [4–11 days] and grower [12–38 days]), (ii) HI: C + 5% of the expected daily feed intake (DFI) HI live larvae (calculated on dry matter [DM]) and (iii) TM: C + 5% of DFI TM live larvae (DM). At 39 days of age, birds were slaughtered. Growth performance parameters were overall not affected by dietary treatments, except for the grower phase feed conversion ratio (FCR) and the overall FCR being better in the TM broilers than the others (p < 0.01). No differences were observed for slaughtering performance and haematological and serum parameters, except for the spleen relative weight being higher (p < 0.01) in the birds administered with larvae when compared to the C group. Gut morphometric indexes and histopathological alterations were not influenced by insect larvae administration. In conclusion, the administration in limited quantities of HI and TM live larvae as environmental enrichment has no negative effects on broiler chicken growth performance and health status. A behavioural study could confirm that live insect larvae represent a novel natural environmental enrichment in broiler farming.     

Effect of soybean peptides on growth performance,intestinal structure and mucosal immunity of broilers

Five‐hundred 1‐day‐old broilers were randomly assigned to five groups, 100 chickens for each group. From group 1 to 3, 80, 120 and 200 mg/kg soybean peptides was added to the diets respectively; in the fourth group, 3.2 mg/kg genramycin was added; and the fifth group was the control without soybean peptides and antibiotics. At the age of 28 and 49 days, the number of goblet cells (GC), intestine intraepithelial lymphocyte, immunoglobulin A‐forming cells, the ratio of villous height and crypt depth (V/C) of broiler’s duodenum, jejunum and cecum were observed by the application of haematoxylin and eosin or histochemistry staining. The results indicated that soybean peptides added with 80–120 mg/kg could increase daily weight gain, the number of GC and V/C. Soybean peptides could modulate intestinal mucosal immunity of broilers.     

抗菌肽Thanatin转基因小鼠建立的初步研究

人工合成抗菌肽Thanatin基因的3条片段,利用重叠延伸PCR扩增技术得到完整的Thanatin基因,通过分子克隆方法构建出pIRES2-EGFP-Thanatin重组表达载体。然后与脂质体混合,采用睾丸打点注射将新构建的抗菌肽基因注入小鼠睾丸内,共注射公鼠5只。6周后与雌鼠交配,对新生仔鼠进行断尾,提取尾尖基因组DNA,利用PCR和Southern印迹方法对其进行检测。结果显示,得到的52只新生仔鼠中PCR检测阳性率为38.46%,Southern印迹检测阳性率为30.77%;在活体荧光成像系统下转基因小鼠呈现绿色荧光表达。通过睾丸注射法使Thanatin基因在小鼠的基因组中得到整合,为进一步研究抗菌肽的作用机理、培育抗病动物品种以及通过建立转基因动物生物反应器进行抗菌肽的大量生产奠定了基础。     

超微粉碎对黄连解毒散和白头翁散体外抑菌效果的影响

目的：观察黄连解毒散和白头翁散超微粉的体外抑菌效果。方法：采用超微粉碎和普通粉碎方法将黄连解毒散、白头翁散粉碎成超微粉（300目）和细粉（65目）,用其水提取液和醇提取液采用管碟法进行体外抑菌试验。结果：黄连解毒散、白头翁散超微粉比细粉的抑菌圈直径均显著增大（P〈0.05）。说明超微粉碎可明显提高黄连解毒散和白头翁散的体外抑菌效果。     

Effects of larval size and hydrodynamics on the growth rates of the black fly Simulium tribulatum

Black flies are ubiquitous and important members of lotic ecosystems. Size is known to affect many aspects of their life in the aquatic larval stage, including intraspecific competition for feeding sites. As filter feeders, flow affects their ability to feed and reach sufficiently fast flow. This, in turn, can lead to risky fluid‐mediated dispersal behavior in search of better conditions. It is surprising, therefore, that little information is available regarding how physiological and environmental factors combine to affect larval growth rates. The present study determines the relative growth rates of small (0.6 mm) and large (approximately 4 mm) larvae in laboratory flumes designed to produce spatially homogeneous and temporally consistent flow regimes at ecologically relevant velocities (44 and 64 cm/s). Our results indicate that size and flow both influence growth rates and that the 2 interact significantly. Young larvae exhibit faster growth rates and a greater positive response to increased flow speed. This result might help explain why smaller larvae have a greater propensity to disperse than larger larvae: the benefit of increased growth rate that they receive from relocating to faster flow might balance the risks inherent in dispersal.