绿洲区苜蓿与鸭茅混播饲草的青贮发酵品质研究

以苜蓿(Medicago sativa)与鸭茅(Dactylis glomerata)混播草地牧草为材料,按照90%苜蓿+10%鸭茅、70%苜蓿+30%鸭茅、50%苜蓿+50%鸭茅的比例进行青贮,通过分析对比发酵品质、营养成分、感官青贮效果等,以期优化最佳混合青贮的豆∶禾比例。试验结果表明:苜蓿和鸭茅混合青贮后,气味、质地、色泽感官评定均为优良,且pH呈下降趋势,青贮效果优于苜蓿和鸭茅的单独青贮。混合青贮降低了苜蓿青贮中氨态氮含量的36.4%,鸭茅青贮中乙酸、丙酸的含量明显下降;提高了苜蓿青贮中乳酸的含量,有效抑制了丁酸的产生,苜蓿+鸭茅饲草混贮比例为7∶3和5∶5处理结果未检测出丁酸。3个混合青贮组合的粗蛋白含量高出鸭茅单贮31.9%,酸性洗涤纤维低于鸭茅青贮12.6%。在青贮发酵过程中,苜蓿+鸭茅以7∶3比例混合青贮,有利于提高青贮饲料的发酵品质。     

地衣芽孢杆菌对发酵床饲养仔猪生长性能、消化酶活性及肠道主要菌群数量的影响

本试验旨在研究发酵床饲养模式下日粮中添加地衣芽孢杆菌对仔猪生长性能、胰腺和小肠黏膜消化酶活性及肠道主要菌群数量的影响。选用108头体重13kg左右的35日龄健康苏钟猪,随机分为3组,每组3个重复,每个重复12头,分别饲喂基础日粮(对照组)、基础日粮+40mg/kg杆菌肽锌+20mg/kg硫酸黏杆菌素(抗生素组)、基础日粮+300mg/kg地衣芽孢杆菌(益生菌组)的试验日粮。预试期7d,正试期52d。结果表明:1与对照组相比,日粮中添加地衣芽孢杆菌能够在一定程度上提高仔猪平均日增重、平均日采食量,降低料重比,但各组间差异均不显著(P0.05)。2与对照组相比,日粮中添加地衣芽孢杆菌能够极显著提高仔猪胰腺中淀粉酶活性、十二指肠黏膜中麦芽糖酶活性和空肠黏膜中乳糖酶活性(P0.01),十二指肠黏膜和空肠黏膜中蔗糖酶活性显著提高(P0.05)。3与对照组相比,日粮中添加地衣芽孢杆菌能够显著提高仔猪盲肠芽孢杆菌数量(P0.05);乳酸杆菌数量较对照组提高4.09%,大肠杆菌数量较对照组降低4.86%,但均未达到显著水平(P0.05)。综上所述,在本试验条件下,日粮中添加300mg/kg地衣芽孢杆菌能够提高发酵床饲养仔猪胰腺、小肠黏膜消化酶活性及盲肠芽孢杆菌数量,同时仔猪生长性能也在一定程度上有所改善。     

Effects of Different Substrates on Fermentation Parameters

Fermenting different raw materials (corn, soybean meal and cottonseed meal) with three kinds of strains (Lactobacillus, yeast and Bacillus subtilis) were employed to optimize the fermentation parameter with sensory evaluation, pH and amount of probiotics retention.The results showed that the time to reach stable pH of materials with different substrates was different.Cottonseed meal had the longest time to reach stable pH followed by soybean meal, while corn had the shortest time under the condition of same water content.Different substrates had no effect on initial pH of corn, soybean meal and cottonseed meal.The count of the probiotics was also influenced by different substrates.When pH reached steady state, corn had the largest number of the probiotics followed by soybean meal and cottonseed meal.The color and smell of three materials after fermented had distinctive features.But cottonseed meal had the highest viscosity followed by soybean meal and corn.Because of shorter time and more microorganisms, corn was better than soybean meal and cottonseed meal to be fermenting medium.     

养殖模式对冬季商品肉鸭舍温湿指数的影响

选择1日龄健康樱桃谷SM3系商品代肉鸭18 490羽,随机分为网上(N组)和发酵床上(B组)2组进行饲养,监测冬季一个完全生长周期内(42d)鸭舍温度(T)、相对湿度(RH)及温湿指数(THI)变化,探讨不同养殖模式对商品肉鸭舍温湿指数的影响。结果表明:N组和B组舍内平均温度均明显高于平均气温;N组舍内温度全部高于B组,N组平均温度比B组高8.32℃,差异显著(P0.05)。N组和B组舍内相对湿度均明显高于室外;N组舍内平均相对湿度比B组高2.47%,无显著性差异(P0.05)。试验期N组有16d处于热应激状态,B组有6d处于冷应激状态。结果提示,在北方寒冷气候下网上供暖养殖模式能为商品肉鸭提供更舒适的温湿度条件。     

抗菌肽对发酵床饲养仔猪抗氧化指标、免疫指标及肠道主要菌群数量的影响

为研究发酵床饲养模式下饲粮中添加抗菌肽对仔猪生长性能、抗氧化指标、免疫指标及盲肠主要菌群数量的影响,选用108头35日龄,体重13kg左右的健康苏钟猪,随机分为3组,每组3重复,每重复12头猪,分别饲喂基础饲粮(对照组)、基础饲粮+40mg/kg杆菌肽锌+20mg/kg硫酸抗敌素(抗生素组)和基础饲粮+300 mg/kg抗菌肽(抗菌肽组),试验期49d。结果表明:(1)与对照组相比,饲粮中添加抗菌肽能够显著提高仔猪血清和肝脏中谷胱甘肽过氧化物酶活性(P0.05),极显著降低肝脏丙二醛含量(P0.01);抗菌肽组肝脏谷胱甘肽过氧化物酶活性比抗生素组极显著提高(P0.01)。(2)与对照组相比,饲粮中添加抗菌肽能够极显著提高仔猪十二指肠上皮内淋巴细胞数量(P0.01);抗菌肽组仔猪血清IgA含量分别比对照组和抗生素组提高4.03%、2.27%,抗菌肽组空肠上皮内淋巴细胞数量比对照组提高10.70%,但差异均不显著(P0.05)。(3)与对照组相比,饲粮中添加抗菌肽能够显著降低仔猪盲肠中大肠杆菌数量(P0.05);细菌总数降低5.98%,但差异不显著(P0.05)。综上所述,本试验条件下,饲粮中添加300mg/kg的抗菌肽能够提高仔猪抗氧化和免疫功能;减少仔猪盲肠中大肠杆菌数量,而对盲肠有益菌群无不良影响。     

体外法研究生石膏对瘤胃发酵、甲烷生成及微生态的影响

通过体外产气法研究了生石膏对瘤胃发酵、甲烷生成及微生态的影响。按单因子试验设计,在底物中分别按其干物质的0(对照组)、1.25%(低水平组)、2.5%(高水平组)添加生石膏,每个组设4个重复,进行24h体外发酵培养。结果显示,随生石膏添加水平升高,乙酸与总挥发性脂肪酸浓度、乙酸与丙酸的浓度比、12和24h产气量、氢的生成量及甲烷菌数量显著(P0.05)或极显著(P0.01)降低,而丙酸占总挥发性脂肪酸的比例与原虫数量极显著(P0.01)升高;生石膏添加会显著(P0.05)或显著(P0.01)降低12和24h甲烷产量,而高水平添加会显著(P0.05)降低丙酸浓度与乙酸占总挥发性脂肪酸的比例。结果表明,生石膏可通过减少氢的供应量和抑制甲烷菌生长而降低体外甲烷产量,同时会促进原虫增殖,致使2种添加水平的相对甲烷抑制潜势没有显著(P0.05)差异。     

Treatment of tropical forages with exogenous fibrolytic enzymes: effects on chemical composition and in vitro rumen fermentation

The effects of three treatments of fibrolytic enzymes (cellulase from Trichoderma longibrachiatum (CEL), xylanase from rumen micro‐organisms (XYL) and a 1:1 mixture of CEL and XYL (MIX) on the in vitro fermentation of two samples of Pennisetum clandestinum (P1 and P2), two samples of Dichanthium aristatum (D1 and D2) and one sample of each Acacia decurrens and Acacia mangium (A1 and A2) were investigated. The first experiment compared the effects of two methods of applying the enzymes to forages, either at the time of incubation or 24 h before, on the in vitro gas production. In general, the 24 h pre‐treatment resulted in higher values of gas production rate, and this application method was chosen for a second study investigating the effects of enzymes on chemical composition and in vitro fermentation of forages. The pre‐treatment with CEL for 24 h reduced (p < 0.05) the content of neutral detergent fibre (NDF) of P1, P2, D1 and D2, and that of MIX reduced the NDF content of P1 and D1, but XYL had no effect on any forage. The CEL treatment increased (p < 0.05) total volatile fatty acid (VFA) production for all forages (ranging from 8.6% to 22.7%), but in general, no effects of MIX and XYL were observed. For both P. clandestinum samples, CEL treatment reduced (p < 0.05) the molar proportion of acetate and increased (p < 0.05) that of butyrate, but only subtle changes in VFA profile were observed for the rest of forages. Under the conditions of the present experiment, the treatment of tropical forages with CEL stimulated their in vitro ruminal fermentation, but XYL did not produce any positive effect. These results showed clearly that effectiveness of enzymes varied with the incubated forage and further study is warranted to investigate specific, optimal enzyme‐substrate combinations.     

不同代谢葡萄糖水平对绵羊人工瘤胃发酵特性、微生物蛋白质浓度和产气参数的影响

本试验旨在通过人工瘤胃体外培养,研究不同代谢葡萄糖水平下的绵羊瘤胃发酵特性、微生物蛋白质浓度和产气参数。采用单因子试验设计,共设计4个代谢葡萄糖水平[125(A)、138(B)、153(C)、168 g/kg(D)]。体外试验所用瘤胃液采自4只安装有永久性瘤胃瘘管的绵羊。分别于培养0、2、4、6、8、12、24 h采集2 mL培养液用于分析。结果表明:1)8~24 h培养液pH随着代谢葡萄糖水平的提高而出现显著或极显著下降(P0.05或P0.01);氨氮浓度在2 h时D组显著高于A组(P0.05),而在6 h时A组显著高于其他3组(P0.05)。2)D组6h培养液细菌蛋白浓度显著高于A组(P0.05);随着代谢葡萄糖水平的提高,培养液丙酸、丁酸、总挥发性脂肪酸的浓度总体呈升高趋势,乙酸/丙酸呈下降趋势。3)随着代谢葡萄糖水平的提高,理论最大产气量极显著降低(P0.01),达1/2理论最大产气量的时间极显著缩短(P0.01);潜在产气量无显著变化(P0.05),24 h产气量和产气速率常数分别显著或极显著下降和上升(P0.05或P0.01)。结果提示,提高代谢葡萄糖水平,可以提高丙酸、总挥发性脂肪酸的浓度,同时可为绵羊提供较多的生糖前体物质。     

蚕沙和稻秸不同比例组合对瘤胃微生物体外发酵的组合效应

本文采用瘤胃微生物体外发酵法研究了不同比例蚕沙(SE)和稻秸(RS)的组合效应。试验将SE:RS设计为100∶0(SE100组)、80∶20(SE80组)、60∶40(SE60组)、40∶60(SE40组)、20∶80(SE20组)、0∶100(SE0组)的比例,分别进行体外发酵批次培养24 h和体外发酵产气培养72 h,测定产气参数和发酵特性指标。结果表明:1)SE100组理论最大产气量显著高于其他各组(P<0.05),SE80组的24和72 h累积产气量显著高于其他组(P<0.05)。2)24 h时培养液总挥发性脂肪酸浓度为SE80组>SE100组>SE60组>SE40组>SE0组>SE20组,乙酸/丙酸为SE80组SE100组>SE60组>SE80组>SE40组>SE0组。4)随着蚕沙比例的升高,底物体外有机物消化率越高。5)SE80组多项指标组合效应指数为0.76,SE80组>SE40组>SE60组>SE20组。蚕沙和稻秸组合改善了体外瘤胃微生物发酵特性和产气参数,且蚕沙和稻秸的最佳比例为80∶20。     

越红工夫茶加工技术及品牌建设研究

本文阐明了越红工夫茶的历史背景和现状,提出了越红工夫茶鲜叶、萎凋、揉捻、发酵、干燥等初制加工工序的操作方法和技术要求,以规范越红工夫茶加工技术,保持品质特征,稳定产品质量。同时,阐述了对越红工夫茶品牌建设的研究。