不同RDP/RUP比例日粮对鲁西黄牛瘤胃发酵的影响

试验选用3头体况健康,体重350 kg左右,并安装有瘤胃瘘管的鲁西黄牛,采用3×3拉丁方试验设计,饲喂3种RDP/RUP比例分别为1.00∶1.00(A组)、1.22∶1.00(B组)、1.50∶1.00(C组)的等能等氮日粮,研究其对瘤胃内环境参数的昼夜动态变化规律的影响。结果表明:瘤胃pH受日粮RDP/RUP比值差异的影响不显著(P>0.05),A、B和C组pH变化范围分别为6.53~6.94、6.44~6.84和6.45~7.03。各组瘤胃pH均在饲喂后2~4 h达到最低值,随后逐渐上升;瘤胃液尿素氮以C组最高,A、B 2组差异不显著(P>0.05)。各组瘤胃液尿素氮在08:00饲喂后2 h达到最高值,但20:00饲喂后各组变化趋势不一致。A、B 2组瘤胃液尿素氮浓度白天较低,夜晚较高,而C组正好相反;各组瘤胃液氨氮平均浓度差异不显著(P>0.05),动态变化趋势基本相同,均在饲喂后2 h达到最高值;瘤胃微生物蛋白(MCP)平均浓度随RDP/RUP比值升高而显著提高,C组显著高于A、B 2组(P<0.05)。各组瘤胃液MCP浓度均在饲喂后2 h达到最低值。结果显示,以瘤胃液MCP浓度为衡量指标,日粮适宜的RDP/RUP比例为1.50∶1.00。     

平菇培养料发酵过程理化因素及微生物变化研究

通过对平菇(Pleurotus ostreatus)玉米芯培养料进行发酵处理,监测玉米芯发酵料的堆温和pH值变化,对不同发酵阶段进行微生物区系分析并测定了发酵过程中脱氢酶和碱性磷酸酶的变化。结果表明,在玉米芯培养料的发酵过程中,堆温先升高后降低,而pH值先降低后升高。微生物主要以细菌和放线菌为主,真菌数量很少。随着发酵的进行,细菌和放线菌数量,脱氢酶以及碱性磷酸酶的活性呈逐渐上升趋势。     

五种微生物发酵剂对玉米芯的发酵效果

为了筛选出适合玉米芯发酵的微生物菌剂,以不加菌剂为对照,研究了添加5种微生物菌剂对玉米芯的发酵腐熟效果和发酵过程中堆料温度、体积、营养的动态变化。结果表明:添加外源微生物菌剂能有效加快玉米芯发酵并显著影响营养元素的动态变化,其中添加"金宝贝"菌剂促进发酵的效果最好。5种处理中"金宝贝"升温速度最快,最高温度达52.6℃,50℃高温可持续5 d以上,且体积下降百分比最高达12%之多,速效营养释放量最高。与对照相比,各处理发酵至30 d时异味消失体积下降明显且表层出现大量菌丝,达到腐熟。5种处理全氮与碱解氮含量变化正好相反:全氮含量先下降后上升而速效氮含量先增加后减少;全磷、速效磷、全钾、速效钾含量均呈上升趋势;而对照升温缓慢、营养元素含量变化不明显。     

鸡深层发酵制作营养酱油的研究

鸡(土从)连续发酵生产营养酱油,其最适接种量为20％,发酵时间7d;果胶酶和纤维素酶混合处理发酵液,可显著提高氨基态N和总N含量,氨基酸生成率达62.8％。     

影响原料奶发酵因素的初探及其控制

通过用保加利亚乳杆菌和嗜热链球菌(1:1)3%的接种量,42.5℃培养,做发酵试验分析,主要存在以下几个因素影响着原料乳的发酵质量:抗生素的残留量、原始酸度和pH值、蛋白含量和总固体含量。通过实验发现脂肪对其影响不大。     

利用甘蔗糖蜜生产饲料酵母发酵条件的研究

以甘蔗糖蜜为碳源发酵生产高生物量饲料酵母,通过单因素正交试验设计,确定优化的培养条件为:温度28℃,pH5.0,装液量200mL/500mL,摇床转速180r/min,培养时间84h。在优化的培养条件下酵母菌株的总蛋白质含量可达到6.01g/L。     

灌注果寡糖对生长绵羊瘤胃发酵功能的影响

采用营养灌注技术研究了果寡糖对生长绵羊瘤胃发酵功能的影响。试验选取6只安装有永久性瘤胃瘘管的内蒙古半细毛羯羊，随机分为两组，试验组一灌注1．00％果寡糖，试验组二灌注2．00％果寡糖。结果表明：灌注果寡糖可以显著（P〈0．05）降低试羊的瘤胃液相pH和瘤胃内的NH3-N浓度，显著提高（P〈0．05）瘤胃内的VFA含量和MCP含量。两个灌注水平都可以提高生长绵羊的瘤胃发酵功能。但2．00％的灌注水平仅在瘤胃NH3-N浓度的降幅方面比1．00％的灌注水平显著增大（P〈0．05），在对瘤胃液相pH值、VFA含量和MCP含量的影响方面两个灌注水平没有显著差异（P〉0．05）。     

猪用发酵床的研究与应用

新型微生物发酵床养猪技术是一种新兴的无公害养猪技术,它可有效地解决猪生产中的粪便处理和环境污染问题,改善猪的福利状况,利于猪只的生长和发育,其环保性和经济性明显优于集约化,规模化养猪方式。本文介绍了微生物发酵床的概念、分类和工艺流程,讨论了其技术要点和应用效果,并对其发展前景进行了展望。     

Seasonal changes in digestibility, passage rate and rumen fermentation of alfalfa hay in sika deer (Cervus nippon) under restricted feeding

To investigate seasonal variations in the digestive functions of sika deer, five female sika deer were provided with an amount of alfalfa hay cubes equivalent to voluntary food intake during winter. We measured the rate at which the food passed through the digestive tract, digestibility and rumen fermentation during the summer (August), autumn (November), winter (February) and spring (May). Total mean retention time in the digestive tract during summer and autumn was numerically longer than that in winter and spring, but the difference did not reach significance. Organic matter and fiber were less digestible in summer and autumn than in winter and spring (P < 0.05), whereas the digestibility of the dry matter tended to vary with the seasons (P < 0.1). Ruminal pH values seasonally changed (P < 0.01), and were the lowest in autumn. The concentration of ruminal ammonia‐nitrogen differed significantly among the seasons (P < 0.05), increasing in winter and decreasing during spring and summer. The numbers of protozoa changed significantly among the seasons (P < 0.05), being higher in autumn than in winter and spring, and intermediate in summer. The concentration of total volatile fatty acids was not seasonally affected, but the molar percentages of propionic acid and butyric acid significantly changed according to season (P < 0.05 and P < 0.01, respectively), and the ratio of acetic to propionic acid tended to change with the seasons (P < 0.1). The results of this study suggested that the digestive functions in sika deer, fed a commercial diet at a restricted level, differed notably among the seasons and these variations might partially be due to environmental effects.     

Effects of amino nitrogen on fermentation parameters by mixed ruminal microbes when energy or nitrogen is limited

Ruminal microbes harvested from a ruminally fistulated cow were incubated in simple batch and semicontinuous cultures with NH₃‐N or amino‐N on nitrogen‐ or energy‐excess diets in quantity (HN and LN diets, respectively, consisting of timothy hay plus soybean meal, or corn grain), based on evaluation with the National Research Council and Cornell Net Carbohydrate and Protein System models. In a batch culture experiment, supplementation with amino‐N promoted digestion and fermentation in the course of incubation (4–24 h) on both diets, but these effects mostly disappeared when the diets were sufficiently digested (at 48 h). In a semicontinuous culture experiment using Rusitec, no effect of amino‐N was exhibited after sufficient fermentation and digestion, but significant promotion of digestion was shown in the course of incubation on the HN diet, while no such effect was detected on the LN diet. The microbial yield for 24 h did not show a significant difference between the N sources of either of the two diets. These results suggest that the stimulatory effects of amino‐N are diminished when the diets are sufficiently digested after a long retention and incubation, and also that the effectiveness of amino‐N does not require a quantitatively energy‐excess status.