大蒜素对肉鸡生产性能和消化酶活性的影响

135只1日龄AA鸡随机分成A、B、C3组,每组设3个重复,每个重复15只。A为空白对照组,饲喂基础日粮,B为抗生素组,在基础日粮中添加50mg／kg洛克沙生和750mg／kg10％金霉素,C为试验组,在基础日粮中添加160mg／kg25％大蒜素,以研究大蒜素对肉鸡生产性能和十二指肠消化酶活性的影响。试验结果表明,A、B、C3组肉鸡平均体重和平均日增重差异不显著（P〉0．05）,与A组相比,42日龄时C组料重比差异显著（P〈0．05）。在21日龄和42日龄时,C组淀粉酶活性较A组提高了122．87％（P〈0．01）和40．50％（P〈0．01）,脂肪酶活性较A组提高了89．98％（P〉0．05）和33．33％（P〉0．05）,总蛋白酶活性较A组提高了10．29％％（P〉0．05）和1．7％（／9〉0．05）。本结果提示在肉鸡饲料中添加大蒜素能够提高饲料效率和肠道淀粉酶活性。     

复合菌系固体发酵产纤维素酶的影响因素研究

以B-1（Bacillaceaesp.）、B-2（Pseudomonassp.）、F-1木霉属（Trichodermasp.）、F-2木霉属（Trichodermasp.）和F-3青霉属（Penicillumsp.）组成复合菌剂,通过固体发酵培养,研究了温度、pH、时间和接种量对复合菌系固体产酶发酵的影响.实验结果得到了复合菌系的最佳产酶温度、pH、培养时间和接种量分别为32℃p、H 7.65、d、8%~10%,相对应的CMCase和Fpase的活力分别达到2501 IU/g和847 IU/g、2036 IU/g和744 IU/g、2674 IU/g和673 IU/g2、644 IU/g和578 IU/g.     

低聚壳聚糖对肉仔鸡生长性能及免疫器官发育的影响

480羽1日龄AA肉鸡,随机分为4组,每组120羽,设6个重复,其中空白对照组饲喂玉米-豆粕型基础日粮,抗生素组基础日粮添加50mg/kg金霉素,试验Ⅰ组(低聚壳聚糖剂量组)和试验Ⅱ组(黄芪多糖高剂量组)分别添加20mg/kg和40mg/kg低聚壳聚糖,试验期42d,研究低聚壳聚糖对肉仔鸡生长性能及免疫器官发育的影响。结果显示,试验Ⅰ、Ⅱ组肉仔鸡的平均体重、日增重、免疫器官重量及其指数均不同程度高于同期空白对照组和抗生素组,其中平均体重与日增重多差异显著(P<0.05),部分免疫器官重量与指数有统计学意义(P<0.05);平均料重比均较明显地低于同日龄空白对照组和抗生素组。试验结果表明,基础日粮添加20、40mg/kg低聚壳聚糖对肉鸡的生长性能及免疫器官发育具有较明显的促进作用,可提高肉鸡的平均日增重和饲料转化率,增强机体的免疫功能。     

Partitioning and purification of extracellular β-1,3-1,4-glucanase in aqueous two-phase systems

The partition behaviors of β-1,3-1,4-glucanase, α-amylase and neutral proteases from clarified and whole fermentation broths of Bacillus subtilis ZJF-1A5 were investigated. An aqueous two-phase system (polyethylene glycol (PEG)/MgSO4)was examined with regard to the effects of PEG molecular weight (MW) and concentration, MgSO4 concentration, pH and NaCl concentration on enzyme partition and extraction. The MW and concentration of PEG were found to have significant effects on enzyme partition and extraction with low MW PEG showing the greatest benefit in the partition and extraction of β-glucanase with the PEG/MgSO4 system. MgSO4 concentration influenced the partition and extraction of β-glucanase significantly. pH had little effect on β-glucanase or proteases partition but affected α-amylase partition when pH was over 7.0. The addition of NaCl had little effect on the partition behavior of β-glucanase but had very significant effects on the partitioning of α-amylase and on the neutral proteases. The partition behaviors of β-glucanase, α-amylase and proteases in whole broth were also investigated and results were similar to those obtained with clarified fermentation broth. A two-step process for purifying β-glucanase was developed, which achieved β-glucanase recovery of 65.3% and specific activity of 14027 U/mg, 6.6 times improvement over the whole broth.     

酶在食品工业、轻工业和环境保护上的应用分析

概述了酶在食品工业、轻工业和环境保护中的主要应用。这些酶主要为:淀粉酶、果胶酶、纤维素酶、β-葡萄糖苷酶、蛋白酶、脂肪酶、植酸酶、木聚糖酶、漆酶、过氧化物酶、几丁质酶和几种极端酶,并探讨一些新型酶的应用前景。     

腐植酸钠对AA肉鸡屠宰性能及肌肉品质的影响

探讨腐植酸钠对AA肉鸡屠宰性能及肌肉品质的影响。方法:240只1日龄AA肉鸡,公母各半,随机等分4组,每组2个重复,每个重复30只。Ⅰ组为空白对照,饲喂基础日粮;Ⅱ、Ⅲ、Ⅳ组为试验处理,饲喂基础日粮并分别添加1.0g/kg、1.5 g/kg、2.5g/kg的腐植酸钠。42日龄每个重复随机抽取4只,测定屠宰率、半净膛率、全净膛率、胸肌率、腿肌率、腹脂率、瘦肉率及肌肉(胸肌、腿肌)色度、嫩度、失水率。结果:1)Ⅲ组的全净膛率显著(P<0.05)高于对照组,其余各指标各组间差异不显著(P>0.05)。2)Ⅱ组胸肌失水率显著大于对照组(P<0.05);各试验组腿肌失水率都极显著(P<0.01)大于对照组;其余各指标各组间无显著差异(P>0.05)。结论:1)AA肉鸡日粮中添加腐植酸钠可显著提高全净膛率(P<0.05),对屠宰率、半净膛率、胸肌率、腿肌率、腹脂率、瘦肉率均表现出一定的改善趋势。2)添加腐植酸钠对AA肉鸡肌肉品质有一定的负面影响。     

早期饲喂对肉鸡生长性能和肠道消化酶的影响

为研究早期饲喂对肉鸡生长性能和肠道消化酶的影响,选择360只刚出壳的AA肉用雏鸡,采用单因子试验设计,随机分成4个处理组,每组4个重复,每个重复20只,试验1组出壳后12 h饲喂,试验Ⅱ组出壳24 h后饲喂,试验Ⅲ组出壳36 h后饲喂,对照组出壳48 h后饲喂.饲喂相同日粮,试验期为6周.于21日龄和42日龄分别测定肉鸡进行生产性能和酶活性.结果表明：早期饲喂显著提高了肉鸡的日增重,降低了料重比,试验Ⅰ组和试验Ⅱ组与对照组相比,日增重分别提高了4.19%和3.70%,料重比分别降低5.61%和5.10%,差异显著（P〈0.05）;试验Ⅰ组、试验Ⅱ组和试验Ⅲ组肠道消化酶水平高于对照组.早期饲喂提高了肉鸡肠道消化酶水平,以出壳后12 h饲喂最好.     

产纤维素酶真菌菌株的分离及其降解作用的研究

为了获得高产纤维素酶菌株,有效地开发和利用纤维素资源.本研究通过对野外采集的大型真菌进行分离纯化,获得了16个菌株.利用CMC固体培养、刚果红染色,测量水解圈与菌落直径的比值(H/C值),对获得的菌株进行初筛;通过液体发酵培养,测定其上清液中的滤纸酶活力(FPA),对菌株进行复筛,最终获得了纤维素酶活性较高的菌株01.以稻草和羧甲基纤维素为碳源,研究了培养温度、pH值、培养时间对真菌菌株01产纤维素酶的影响.结果表明,该菌株产纤维素酶的最适培养温度为27℃,pH值为5.0,培养时间为6 d,菌株01的滤纸酶活性达到580.0 IU/mL.因此,真菌01可作为纤维素酶研究和饲料加工等生产的备选菌株.     

Changes in biochemical constituents and induction of early sprouting by triadimefon treatment in white yam （Dioscorea rotundata Poir.） tubers during storage

The ability of triadimefon(TDM),a triazolic fungicide,to alter the biochemical constituents and thereby minimizing the days required for sprouting in white yam(Dioscorea rotundata Poir.) tubers during storage under(30±2) °C in the dark,was studied.TDM at 20 mg/L was given to tubers by dipping the tubers in treatment solution containing 20 mg/L TDM on 10,25 and 40 d after storage(DAS).Starch,sugars,protein,amino acid contents as well as protease and α-amylase activities were estimated on 15,30 and 45 DAS from two physiological regions viz.,apical and basal regions of the tubers.In normal conditions(control) sprouting occurred on 70 to 80 DAS.The starch content decreased,while protein,amino acid,sugar contents and protease and α-amylase activities were increased due to TDM treatment and led to early sprouting.     

Optimization of cultural conditions for thermostable β-1, 3-1, 4-glucanase production byBacillus subtilis ZJF-1A5

The optimization of cultural conditions for β-glucanase production byBacillus subtilis ZJF-1A5 was investigated in flask trials. Temperature had great effect on β-glucanase production which maximized at optimal temperature of 37°C and decreased significantly when temperature was over 37°C. Charge quantity affected β-glucanase production significantly. Adding oxygen vector N-dodecane or acetic ether benefited β-glucanase production, but it depended on the concentration and charge quantity. The results of fractional factorial design showed that age and size of inoculum and shaking speed were the key factors affecting β-glucanase production and the cultivation time span to reach the highest β-glucanase activity. The optimal cultural conditions for β-glucanase production obtained with CCD were as follows: inoculum age and size (16 h, 3.82% (v/v)), shaking speed 210 r/min, charge quantity of 30 mL in 250 mL flask and initial pH 7.0, cultured at 37°C for 50 h. Repeated experimental results accorded with those predicted by a second-order polynomial model. The amount of β-glucanase, α-amylase and neutral protease produced byB subtilis ZJF-1A5 was associated partially with cell growth. Those three enzymes' activities increased following the cell growth and increased significantly when cells entered the stationary phase. Project (No. B0608) supported by the National Natural Science Foundation of China and a grant (2001121B25) from Hangzhou Science and Technology Development Project of Zhejiang Province, China     

限饲日龄对肉鸡福利指标和免疫器官发育的影响

本研究采用数量限饲,探讨不同限饲起始日龄对肉鸡整个生产周期中的福利状况和免疫器官发育的影响.[方法]选1日龄AA肉用仔鸡360只,随机分为3个处理,每个处理设3个重复,每个重复40只.Ⅰ组为对照组,Ⅱ、Ⅲ组的限饲开始日龄分别为8日龄和12日龄,限饲组限饲时间为7d,限饲强度均为对照组前一天采食量的80％,限饲组在非限饲期与对照组肉仔鸡均为自有采食和饮水.[结果]早期限饲可显著降低35日龄、42日龄肉鸡胫骨长、尺骨长不对称性综合FA（P ＜0.05）;42日龄时肉鸡足底和腿关节的重度、中度和轻度灼伤各组之间差异不显著（P＞0.05）,但无灼伤率两试验组与对照组差异显著（P＜ 0.05）;42日龄时肉鸡的腿肌率、胸肌率两试验组与对照组差异季显著（P＜0.01）.早期限饲显著提高了肉鸡28日龄的法氏囊指数（P＜0.05）,8-14日龄限饲对28日龄时的脾脏指数影响显著（P＜0.05）;各处理组在14日龄、21日龄、28日龄、35日龄和42日龄时NDV抗体滴度差异不显著（P＞0.05）,但在28日龄后的血液中ND的抗体滴度增幅,试验Ⅱ、Ⅲ组高于对照组.[结论]8-14日龄限饲可有效改善肉鸡的福利状况,促进了免疫器官的发育,提升了饲养后期肉鸡血清中的ND抗体滴度.     

日粮中添加茶多酚对肉仔鸡脂肪沉积的影响

为研究日粮中添加茶多酚对肉仔鸡脂肪沉积及色泽的影响,试验选用1日龄AA鸡200只随机分成4组,每组50只,对照组饲喂基础日粮,试验组日粮为在基础日粮中分别添加100 mg/kg、250 mg/kg、500 mg/kg的茶多酚,于14、28、42日龄每组随机抽取5只进行屠宰,测定腹脂重、腹脂色泽。结果日粮中添加不同水平茶多酚,肉鸡的腹脂重、腹脂率均有明显的降低,且随茶多酚添加剂量增加而降低,当剂量增加到500 mg/kg时,差异极显著(P<0.01);腹脂的L值(亮度)和a值(红度)随剂量增加而降低,b值(黄度)随剂量增加而升高,以添加250 mg/kg时,茶多酚对脂肪色泽改变效果最佳。结果表明日粮中添加不同剂量的茶多酚可以降低腹脂沉积,加深脂肪色泽,改善肉仔鸡的胴体品质。     

y-氨基丁酸和维生素E对AA肉鸡胸肌生长的影响

目的：研究y-氨基丁酸（GABA）对肉鸡胸肌生长的影响,并进一步探讨y-氨基丁酸（GABA）和维生素E（VE）联合应用时是否具有协同作用。方法：试验将300只鸡随机分为6个试验组,每组50羽。其中试验I组为对照组,试验Ⅱ、Ⅲ、Ⅳ组日粮中分别添加25mg／kg、50mg／kg、75mg／kg的GABA,试验V、Ⅵ组日粮中分别添加50rag／kgGABA＋50mg／kgVE和50mg／kgGABA＋100mg／kgVE。在21日龄和42日龄分剐采样,显微镜下测算肌纤维直径。结论：在日粮中添加GABA对肉仔鸡体重和胸肌生长有一定的影响,且具有一定的剂量依赖性,其中以中剂量（50mg／kg）的GABA应用效果最佳。日粮中添加25mg／kg的GABA可以显著提高21日龄肉鸡胸肌肌纤维直径,促进早期肌肉生长,而一定剂量GABA（50rag／kg）与VE（50-100mg／kg）联合应用可显著降低42日龄胸肌肌纤维直径,进而改善肉品质。     

复方中草药对AA肉鸡肌肉抗氧化能力的影响

目的:研究复方中草药对肉鸡肌肉抗氧化能力的影响。方法:选用健康1日龄AA肉鸡400羽,随机分为对照组和试验Ⅰ、Ⅱ、Ⅲ组,每组100羽。对照组饲喂玉米-豆粕基础日粮,试验Ⅰ、Ⅱ、Ⅲ组分别在基础日粮中添加0.5%、1.0%和1.5%的复方中草药,试验期42 d。结果:21日龄时,与对照组相比,试验Ⅰ、Ⅱ、Ⅲ组肉鸡胸肌和腿肌SOD和T-AOC活性及GSH-PX含量不同程度升高,MDA含量不同程度降低,其中试验Ⅱ组胸肌T-AOC活性和GSH-PX含量显著升高,胸肌MDA含量显著降低(P0.05);试验Ⅰ和Ⅲ组胸肌SOD活性和试验Ⅲ组腿肌SOD活性和GSH-PX含量也显著升高(P0.05);而各试验组腿肌MDA含量均显著降低(P0.05)。42日龄时,与对照组相比,各试验组胸肌MDA含量均显著降低(P0.05),而试验Ⅱ组胸肌GSH-PX含量显著升高(P0.05),且各试验组腿肌T-AOC活性也均有不同程度的提高。结论:添加不同剂量的复方中草药可不同程度提高肉鸡胸肌和腿肌抗氧化酶活性,降低MDA含量,其中以添加1.0%的复方中草药提高胸肌抗氧化能力效果最好,而添加1.5%的复方中草药提高腿肌抗氧化能力效果较好。     

胚胎注射谷氨酰胺对肉仔鸡早期生长发育的影响

孵化至18d的肉仔鸡活胚蛋240枚,随机分成4个处理组,每组6个重复,每个重复10枚蛋。处理组Ⅰ羊膜腔注射1mL0．75％生理盐水作为对照,处理组Ⅱ、Ⅲ、Ⅳ分别向羊膜腔内注射质量浓度为0．5％、1．0％、1．5％的谷氨酰胺营养液1mL。继续孵化及出壳后分析表明：胚胎注射对胚蛋孵化率没有影响（P〉0。05％）;胚胎注射谷氨酰胺对肉仔鸡出壳重和出壳重／蛋重无显著影响（P〉O．05）;出壳后第3天,试验组体重较对照组有提高的趋势（P〉0．05）,出壳后第7天,1．0％注射组体重比对照组提高10．89％（P〈0．01）,1．5％注射组较对照组体重增加7．33％（P〈O．05）;3日龄肉仔鸡0．5％注射组血浆T4含量较对照组提高23．67％（P〈0．05）;7日龄肉仔鸡1．0％和1．5％注射组血浆T3含量比对照组分别提高了36．63％和26．16％（P〈0．05）。总之,鸡胚注射G1n可促进肉仔鸡早期生长发育,注射对胚蛋孵化率及出壳重无明显影响。     

菌糠饲料喂肉用仔鸡试验

蘑菇、菌糠在四周龄肉用仔鸡日粮中占6％,试验结果比对照组多增重14.3％、饲料消耗下降12.2％。菌糠作饲料,既可降低饲养成本,又可促进食用菌生产和养鸡业的发展,有一定的现实意义。     

Improvement of xylanase production by Aspergillus niger XY-1 using response surface methodology for optimizing the medium composition

Objective: To study the optimal medium composition for xylanase production by Aspergillus niger XY-1 in solid-state fermentation (SSF). Methods: Statistical methodology including the Plackett-Burman design (PBD) and the central composite design (CCD) was employed to investigate the individual crucial component of the medium that significantly affected the enzyme yield. Results: Firstly, NaNO3, yeast extract, urea, Na2CO3, MgSO4, peptone and (NH4)2SO4 were screened as the significant factors positively affecting the xylanase production by PBD. Secondly, by valuating the nitrogen sources effect, urea was proved to be the most effective and economic nitrogen source for xylanase production and used for further optimization.Finally, the CCD and response surface methodology (RSM) were applied to determine the optimal concentration of each sig-nificant variable, which included urea, Na2CO3 and MgSO4. Subsequently a second-order polynomial was determined by mul-tiple regression analysis. The optimum values of the critical components for maximum xylanase production were obtained as follows: x1 (urea)=0.163 (41.63 g/L), x2 (Na2CO3)=-1.68 (2.64 g/L), x3 (MGSO4)=1.338 (10.68 g/L) and the predicted xylanase value was 14374.6 U/g dry substrate. Using the optimized condition, xylanase production by Aspergillus niger XY-1 after 48 h fermentation reached 14637 U/g dry substrate with wheat bran in the shake flask. Conclusion: By using PBD and CCD, we obtained the optimal composition for xylanase production by Aspergillus niger XY-1 in SSF, and the results of no additional expensive medium and shortened fermentation time for higher xylanase production show the potential for industrial utilization.     

不同营养水平日粮对早期饲喂肉鸡生产性能和免疫机能的影响

为研究不同营养水平日粮对早期饲喂的肉鸡生产性能和免疫机能的影响,选择刚出壳AA肉仔鸡480只（雌雄各半）,对照组饲喂常规日粮,试验Ⅰ组饲喂高营养水平日粮,试验Ⅱ组饲喂低营养水平日粮．结果表明：试验Ⅰ组体重分别比对照组和试验Ⅱ组提高5．28％（P〈0．05）和9．61％（P〈0．05）;法氏囊指数分别比对照组和试验Ⅱ组提高6．27％（P〈0．05）和9．75％（P〈0．05）,脾脏指数分别提高5．8％（P〈0．05）和13．84％（P〈0．05）;试验Ⅰ组新城疫抗体水平分别提高2．92％和12．5％（P〈0．05）．高营养水平日粮有利于生产性能和免疫机能的提高．     

糖萜素替代抗生素对仔猪的饲喂效果

本试验比较了含糖萜素(Ⅰ)、含抗生素(Ⅱ)日粮以及空白对照组(Ⅲ)的饲养效果.结果表明:Ⅰ组的平均日增重为472克,料重比为1.84:1;Ⅱ组的平均日增重为431克,料重比为1.98:1;而对照组的平均日增重为399克,料重比为2.12:1,三组猪的生长速度、饲料转化率和腹泻率的差异均达到显著水平(p＜0.05).