小麦日粮NSP和木聚糖酶对肉仔鸡肠道微生物区系的影响

肠道微生物菌群是所有动物消化系统的一个组成部分,由于肠道微生物都是活的有机体,也就是说它们的生存需要营养和空间,这就意味着动物的消化系统对营养物质消化和吸收的能力,部分依赖于其中寄居的微生物菌群的分布及其总量。研究表明,不同微生物菌群的分布决定了代谢过程的范围     

五味子提取物对肉仔鸡肠道微生物的影响

研究在肉仔鸡饲养中以五味子提取物作为添加剂对鸡肠道主要微生物的影响。试验选用1日龄的健康肉仔鸡120只,随机分为2个处理组,每组设4个重复,每个重复15只。采用单因子试验设计,于5日龄进行新生期五味子提取物的调控试验,五味子提取物添加量是0.125%。试验结果表明,日粮中添加五味子提取物能降低盲肠中大肠杆菌的数量(P<0.05),且有利于盲肠中乳酸杆菌的增殖。     

木聚糖酶对肉仔鸡生产性能的影响

768羽1日龄AA肉仔鸡,随机分为6个处理,每个处理分8个重复,每个重复16羽肉仔鸡(公母各半)。6个处理分别为玉米-豆粕型日粮添加木聚糖酶0和1000IU/kg处理组,小麦-玉米-豆粕型日粮添加木聚糖酶0,500,1000和1500IU/kg处理组。试验采用4层立体网上养殖(使用上面3层),饲养周期为1～6周龄(前期和中期)。研究玉米和小麦基础日粮中单独使用木聚糖酶对肉仔鸡生产性能的影响。结果表明:玉米-豆粕型日粮中添加1000IU/kg的木聚糖酶对肉仔鸡前期和后期的生长性能无显著影响(P>0.05),但有改善的趋势;小麦-玉米-豆粕型日粮中添加木聚糖酶提高了肉仔鸡的采食量,改善了肉仔鸡的饲料转化效率(P<0.05);小麦-玉米-豆粕型日粮中3个木聚糖酶添加水平之间对肉仔鸡生产性能无显著影响,同样对肠道食糜黏度无影响,提示在本研究条件下500IU/kg木聚糖酶能满足分解木聚糖的需要;尽管小麦-玉米-豆粕型添加木聚糖酶改善了动物生产性能,但仍显著低于玉米-豆粕型日粮,提示在生产实践中单独添加一种酶的作用是有限的。     

柠檬酸对肉仔鸡肠道pH值及肠道微生物的影响

长期以来的大量研究证实，胃肠道微生物大多都是有益的并与动物存在着共生关系，这种共生关系表现在畜禽消化道为微生物提供适宜生长的环境，反过来微生物提供了动物所需要的某些营养物质。尽管对消化道微生物作用的认识还不全面，但已取得一些共识：消化道微生物参与机体物质代谢、营养转化和合成，影响营养物质的分解吸收（康白，１９８８）。同时饲料是影响消化道微生物区系建立的主要环境因素之一。本试验拟通过对肉仔鸡十二指肠、盲肠３种正常菌群的观察来研究柠檬酸对肠道正常微生物的影响。１材料与方法１．１试验设计和日粮试验采用…     

木聚糖酶在肉仔鸡日粮中的应用

本文就木聚糖酶的来源、理化性质及其在肉仔鸡生产中的应用作一综述。     

木聚糖酶对肉仔鸡养分利用和消化器官发育的影响

本试验研究了小麦型饲粮中添加木聚糖酶对肉仔鸡养分利用及消化器官发育的影响.将240只1日龄爱拔益加肉仔鸡随机分为4个处理,每个处理5个重复,每个重复12只鸡,分别饲喂在含40%小麦的饲粮中添加不同水平木聚糖酶(0、500、1 000和5 000 U/kg)的试验饲粮.试验期21 d.结果表明,木聚糖酶对17～21日龄肉仔鸡粗蛋白质、钙及总磷利用率及粪便含水率无显著影响(P>0.05);趋于提高17～21日龄肉仔鸡干物质利用率(P=0.093)及表观代谢能值(P=0.110);各组肉仔鸡养分表观利用率无显著差异(P>0.05).添加木聚糖酶未显著影响21日龄肉仔鸡小肠、胃、胰腺和脾脏相对重量(P>0.05).1 000 U/kg酶组显著降低了21日龄肉仔鸡回肠相对长度(P<0.05).木聚糖酶对21日龄肉仔鸡胫骨干重、长度、灰分及磷含量无显著影响(P>0.05).本研究表明:含40%小麦的肉仔鸡饲粮中添加不同水平的木聚糖酶对肉仔鸡养分利用及大部分肠道器官发育均未产生显著作用;超量添加对肉仔鸡养分利用无进一步改善作用,也未产生负面影响.     

小麦日粮中添加木聚糖酶对肉仔鸡生产性能的影响

试验用 6 0 0只爱拔益加肉仔鸡 ,研究了在小麦部分或全部取代玉米配制的日粮中 ,添加木聚糖酶对肉仔鸡的生产性能和养分消化率的影响。试验结果表明 :小麦全部取代玉米后 ,肉仔鸡的小肠食糜粘度、耗料增重比和死淘率显著升高 ,蛋白质、脂肪、淀粉的消化率及能量的利用率均降低 ;在小麦日粮中添加木聚糖酶后 ,耗料增重比和小肠食糜粘度显著降低 (P <0 .0 5 ) ,死淘率降低 71.9% ,能量利用率和蛋白质、脂肪、淀粉的消化率显著提高 (P <0 .0 5 ) ,改善了肉仔鸡的生产性能 ,达到甚至超过玉米日粮的饲喂效果。小麦取代玉米用量的 5 0 %后 ,除小肠食糜粘度显著升高外 ,其余指标与玉米日粮的无显著差异。在小麦和玉米各半的日粮中添加木聚糖酶后 ,只有食糜粘度显著降低 ,其余指标无明显改善。     

木聚糖酶对0～3周龄肉仔鸡肠道食糜黏度和生产性能的影响

1120只AA肉鸡,四种日粮小麦水平30%、40%、50%和60%,四种酶添加量0mg/kg、5mg/kg、10mg/kg、15mg/kg,组合成16种日粮处理,用来研究木聚糖酶对肉鸡肠道食糜黏度和肉仔鸡生产性能的影响.试验结果表明添加木聚糖酶后,可以提高肉鸡1-21日龄的生产性能,并且酶的添加量越高,生产性能的提高幅度越大,但是添加木聚糖酶水平之间没有显著性差异(P＞0.05).日粮中小麦水平越高,肉鸡肠道食糜黏度越大(P＜0.05).添加木聚糖酶后肠道食糜黏度降低(P＜0.05),各酶水平之间未见显著性差异.经回归分析,肠道食糜黏度的下降与肉仔鸡平均日增重和饲料转化效率之间有直线回归关系,其中与饲料转化效率之间回归方程为FCR=1.523+0.201ln(Ⅴ)(R2=0.649),说明肠道食糜黏度对饲料转化效率的影响较大.     

不同寡糖对肉仔鸡肠道微生物的影响

本试验研究了4种寡糖对健康艾维茵肉仔鸡肠道微生态的影响.选用健康艾维茵肉仔鸡20只,随机分为5个处理,每个处理4个重复,每个重复1只鸡,进行为期40 d的饲养试验.试验第1组为对照组,饲喂基础日粮,第2、3、4、5组为基础日粮中分别添加同一水平糖量(0.015％)的低聚异麦芽糖组(GOS)、低聚木糖组(XOs)、果寡糖组(FOS)、甘露寡糖组(MOS).饲喂40 d后,研究寡糖对内仔鸡盲肠微生物(乳酸杆菌、双歧杆菌、大肠杆菌)数量的影响.结果表明,各种低聚糖能显著降低肉仔鸡盲肠微生物中大肠杆菌的数量(P＜0.05),其中XOS能显著提高盲肠微生物中双歧杆菌与大肠杆菌的比值,显示出良好的促进双歧杆菌增值的作用;MOS能显著提高盲肠微生物中乳酸杆菌与大肠杆菌的比值,显示出良好的促进乳酸杆菌增值的作用.     

小麦日粮中添加木聚糖酶对肉仔鸡生长性能的影响

试验通过在不同蛋白水平的小麦基础日粮中添加木聚糖酶,研究木聚糖酶对肉仔鸡增质量、料重比和经济效益的影响。试验将6日龄雏鸡随机分成A、B和C3组,饲料蛋白水平依次降低,A组为对照组,B组和C组分别添加0．05％和0．08％木聚糖酶,饲喂至20日龄。结果表明,与A组相比．在6～14d,3组生长速度基本一致,B组增质量略高于A和C2组,B组料重比略低于A和C2组．各组间差异不显著。在6～20d,B组增质量显著高于C组,料重比B组略低于A和C2组,各组间差异不显著。同时,木聚糖酶在维持正常生长性能条件下,具有良好的经济效益和社会效益。     

The effects of benzoic acid supplementation on the performance of broiler chickens

To determine the efficiency of benzoic acid, a feeding experiment was carried out with 240 one‐day old ROSS 308 cockerels. Birds were divided into three dietary treatments: I (C) – no additives, II (B1) – 0.1% inclusion of benzoic acid, III (B2) – the inclusion of 0.2% benzoic acid. The performance results were similar in birds fed the control diet and the diet with 0.1% of benzoic acid. The dietary inclusion of benzoic acid at 0.2% depressed the growth of broiler chickens (p < 0.05). The dry matter of the digesta increased in the crop and caeca after benzoic acid supplementation. The pH of the caecal contents decreased following benzoic acid supplementation and was the lowest in the B2 group. No differences were found in the pH of the crop, ileal, gizzard digesta and rectum content. Lactic acid bacteria populations were the lowest in the caeca of the B1 group (p < 0.05). Coliform bacteria decreased in the caeca contents following increased benzoic acid supplementation.     

苏云金芽胞杆菌在小鼠肠道的消长及对小鼠肠道菌群的影响

利用选择性培养平板计数法,研究了苏云金芽胞杆菌(Bt)营养体和芽胞在小鼠肠道的数量消长及对小鼠肠道生理性有益菌群(大肠杆菌、双歧杆菌和乳酸杆菌)数量的影响,同时利用基于16S rDNA作为分子标记的变性梯度凝胶电泳(DGGE)研究了Bt对小鼠肠道微生物多样性的影响。结果表明:Bt营养体和芽胞在小鼠肠道内很快死亡,也未对小鼠肠道有益菌群数量和细菌多样性产生不良影响。说明苏云金芽胞杆菌(Bt)营养体及芽胞对小鼠是安全的。     

Evaluation of xylanase in low-energy broiler diets

The objective of the current study was to evaluate the effect of feeding a thermo-tolerant xylanase in low-energy broiler diets on performance and processing parameters. Evaluation criteria included average broiler BW, FCR, livability, carcass yield, and fat pad yields. The experimental design consisted of 3 nutrient profiles: positive control, negative control 1 (−66 kcal/kg), and negative control 2 (−132 kcal/kg). Two xylanase inclusion programs were included in the negative control 1 and 2 diets; 60 g/t was included in the starter and grower diets with either 60 or 100 g/t in the finisher and withdrawal diets, yielding a total of 7 treatment groups with 8 replicate pens per treatment each containing 42-d-old straight-run chicks per treatment (2,352 total broilers). Broilers were reared in floor pens through 45 d of age. The dietary program consisted of 5 dietary phases: starter (1–15 d), grower 1 (16–23 d), grower 2 (24–31 d), finisher (32–38 d), and withdrawal (39–45 d). Body weights and feed consumption were determined on days of dietary changes, including d 15, 23, 31, 38, and 45. On d 45, 4 male and 4 female broilers per replicate (448 total) were subjected to an 8-h feed withdrawal period and processed to obtain carcass and fat pad weights. Reducing the dietary energy level increased FCR and decreased the fat pad weight of broilers in the negative control 2 treatment compared with the positive control. Inclusion of xylanase during the starter phase increased d 15 BW and reduced FCR. The inclusion of xylanase continued to reduce FCR throughout the trial, as compared with diets without xylanase inclusion. Within this study, we have demonstrated the effectiveness of xylanase inclusion in reduced-energy diets (−66 and −132 kcal/kg) to improve FCR of broilers to that of broilers fed energy-adequate diets.     

木聚糖酶在肉鸡小麦型日粮中的作用机理

小麦作为主要能量作物之一在粮食工业中已得到广泛应用,其在饲料工业上的应用也越来越受到人们重视,但其含有的抗营养因子在一定程度上限制了其在饲料工业中的应用。小麦中主要的抗营养因子是阿拉伯木聚糖,而向小麦型基础日粮中添加木聚糖酶是消除其抗营养特性的有效办法。文中介绍了小麦型基础日粮中木聚糖的抗营养特性及其对肉鸡生产性能的负面影响,木聚糖酶的作用机理及在肉鸡小麦型日粮中添加木聚糖酶的作用效果,以期为小麦合理地应用于肉鸡日粮提供参考。     

DGGE技术在瘤胃微生物多态性研究中的应用

利用传统的方法很难鉴别瘤胃微生物的差异,变性梯度凝胶电泳（DGGE）技术就很好地解决了该问题。DGGE是一种新型的用于检测核酸变异和点突变的电泳方法,具有可靠性强、重现性高、方便快捷等优点,可应用于瘤胃微生物群落多样性和动态性分析。     

Thermostable xylanase derived from Trichoderma citrinoviride increases growth performance and non-starch polysaccharide degradation in broiler chickens

ABSTRACT

1. The aim of this trial was to determine the optimal supplementation level of a xylanase enzyme from Trichoderma citrinoviride on growth performance, apparent ileal and total tract nutrient retention, intestinal morphology, and intestinal concentration of volatile fatty acids in broiler chickens.

2. A total of 600 broiler chickens (Ross 308) of mixed sex were randomly allotted to four treatments, on the basis of similar body weight. The dietary treatments were made from a corn-wheat-soy based diet supplemented with either 0, 3750, 7500, or 11 250 XU/kg xylanase and were fed to 32 d of age.

3. A linear response to increasing dietary xylanase was demonstrated for overall weight gain (P < 0.05) and feed conversion ratio (P < 0.05). The apparent total tract digestibility of dry matter and gross energy, and the coefficient of apparent ileal digestibility (CIAD) of N and soluble non-starch polysaccharides were linearly improved when xylanase was added to the diet (P < 0.05). Moreover, a linear increase (P < 0.05) was observed in the CIAD of Arg, Lys, and Try with increasing dietary levels of xylanase.

4. The viscosity of digesta in ileum was linearly decreased when dietary xylanase level increased (P < 0.05).

5. An increase in villus height of the duodenum and jejunum were observed with increasing dietary levels of xylanase (linear, P < 0.05).

6. Overall, the results showed that the effects of dietary xylanase supplementation on broiler performance was determined through effects on nutrient availability and intestinal morphology.     

The antimicrobial activity of lavender essential oil (Lavandula angustifolia) and its influence on the production performance of broiler chickens

The aim of the study was the evaluation of the antimicrobial activity (in vitro) of lavender (Lavandula angustifolia) essential oil (LEO) and the effect of its addition to the drinking water of broiler chickens on their production performance. Antimicrobial activity was determined by establishing the minimum inhibitory concentration (MIC) using a series of microdilutions. Bird experiments were carried out on a commercial farm on 300 Ross 308 broilers. One‐day‐old chicks were randomly assigned to three experimental groups of 100 individuals (five replications of 20 individuals each). In the control group, chickens received drinking water without added essential oil throughout the rearing period. In the LEO_0.2 and LEO_0.4 groups, from 1 to 42 days of bird life, the LEO_0.2 group had 0.2 ml/L of essential lavender oil added to the drinking water, while LEO_0.4 had 0.4 ml/L added. The results of the experiment showed the antimicrobial activity of LEO and its positive effect on the production results of broiler chickens. Application of higher concentration of essential oil (0.4 ml/L) significantly affected production results (BW, FCR, WCR—p < .01). No differences were observed in FI, WI, F:W and mortality (p > .05). In vitro studies indicate a significant effect of LEO on the inhibition of microbial growth. These results encourage further studies on a larger scale that will confirm antimicrobial efficiency and define the mechanisms of action of Lavandula angustifolia essential oil and its individual components.