不同精粗比下添加维生素B12对体外瘤胃发酵和微生物酶活力的影响

本试验通过体外培养法,研究在不同精粗比饲粮中添加维生素B12对体外瘤胃发酵和微生物酶活力的影响。试验采用3×3双因子试验设计,即3个底物精粗比(玉米∶羊草=35∶65、50∶50和65∶35)和3个维生素B12添加量(0、40和90 ng/mL)。体外试验用瘤胃液取自3只安装有永久性瘤胃瘘管的湖羊。体外培养24 h后测定体外瘤胃发酵参数和微生物酶活力。结果显示:1)随着底物精粗比和维生素B12添加量的提高,体外培养24 h的产气量、潜在产气量和有机物消化率极显著地增加(P<0.01),且维生素B12添加量与上述指标存在线性剂量效应(P<0.01)。2)当底物精粗比为50∶50和65∶35时,添加维生素B12显著提高了发酵液中氨态氮、微生物蛋白、总挥发性脂肪酸、乙酸和丙酸浓度(P<0.05),但对丁酸浓度和乙酸/丙酸无显著影响(P>0.05)。3)当底物精粗比为35∶65和50∶50时,添加40 ng/mL维生素B12使发酵液中羧甲基纤维素酶、木聚糖酶活力显著提高(P<0.05);当精粗比为65∶35时,添加90 ng/mL维生素B12使发酵液中羧甲基纤维素酶、木聚糖酶活力显著提高(P<0.05)。结果提示,底物精粗比和维生素B12添加量影响体外瘤胃发酵。添加维生素B12可增加瘤胃微生物酶的活力,从而提高有机物消化率以及微生物蛋白和总挥发性脂肪酸的产量。当底物精粗比(玉米∶羊草)较高(50∶50和65∶35)时,维生素B12的添加效果更明显,并且具有剂量依赖效应。     

重离子注入VB12生产菌诱变高产菌株

维生素B12生产菌2009-106株经重离子50 Gy诱变处理得106-8株,其摇瓶单位较出发菌株2009-106提高了31%,对其发酵培养基优化后,应用于120吨发酵罐生产,明显提高产量。     

钴的动物营养学功能

钴作为动物体内一种必需的微量元素,虽然动物对其需要量并不大,但钴对动物的造血机能、免疫机能、生长发育及繁殖,特别是对反刍动物瘤胃微生物合成VB12等起着重要的作用,钴与其他微量元素合用会有更加明显的效果。钴缺乏会引起动物生产性能的下降,易给畜牧业带来很大经济损失,因此,随着科学研究的深入,钴的重要营养作用也逐渐被发现并受到人们的重视。就钴的生物学作用、钴的营养学作用机制、钴缺乏的发病机制、与其他营养素之间的关系及其在动物营养中的重要作用进行了阐述。     

云南蜂胶化学成分研究(Ⅰ)

从云南蜂胶中获得了两种化合物,经波谱分析为乔松素(pinocembrin)和Δ9(11),12-齐墩果二烯(Δ9(11),12-oleanolic diene),两个化合物均为蜂胶中的活性物质,其中Δ9(11),12-齐墩果二烯首次从云南蜂胶中分离得到,从而进一步阐明了云南蜂胶的药用价值以及为开发利用云南蜂胶资源提供了新的实验依据。     

高产优质杂交稻“川优12号”种植表现及栽培技术

介绍了杂交稻川优12号种植表现及高产栽培技术,栽培技术包括适时播种、培育壮秧、合理密植,插足基本苗、科学水肥管理和病虫害综合防治技术。     

12％井冈霉素·戊唑醇悬浮剂防治水稻稻瘟病试验初报

为了解12%井冈霉素·戊唑醇悬浮剂对水稻稻瘟病(叶瘟和穗颈瘟)的防治效果、使用技术及其对水稻的安全性,每667 m2施用85、100、115 mL等3个不同浓度(制剂量)处理进行水稻稻瘟病防治效果比较试验,两年的试验结果表明:12%井冈霉素.戊唑醇悬浮剂对水稻生长安全,有较好的增产效果,防治水稻稻瘟病效果优良,其中每667 m2施用115 mL药剂处理对水稻叶瘟的防治效果分别为77.90%和75.84%,对水稻穗颈瘟的防治效果分别为77.27%和76.40%,值得在生产上试验示范和推广应用。     

Investigation on the growth of coprophagy-prevented rats with supplemented vitamin B12

The growth of coprophagy-prevented rats was compared under administration of normal levels of vitamin B12 and supplemented amounts. Two experiments in which supplemented amounts of vitamin B12 were administered were conducted under different conditions. Six rats per group were fed under coprophagy-allowed (conventional feeding) and coprophagy-prevented conditions respectively. In the first experiment, coprophagy-prevented rats were fed only feed containing recommended vitamin B12 level and forced fed hydrous faeces, vitamin B12 and folic acid respectively. In the second experiment, coprophagy-prevented rats were fed AIN-93G at the recommended vitamin B12 level (25 microg/kg diet), at 100 times the level and at 1000 times the level respectively. Body weight, feed consumption and amounts of each faeces type were determined in both experiments. In a comparison of body weight gain, we learned that coprophagy prevention reduced the values, but that there was no significant difference in the forced feeding group in the first experiment. Similar results were recognized in the second experiment. Vitamin B12 supplementation was not able to raise feed intake significantly and hence it obviously was not a severely limiting factor under the respective experimental condition which depressed feed intake.     

不同水平未酯化月桂酸对人工瘤胃发酵产气量的影响

利用人工瘤胃体外产气法,精粗比不同(3∶7和4∶6)的两种日粮类型分别用0%、3%、6%和9%(占基础日粮比例)的未酯化月桂酸(C12∶0)取代日粮精料作试验。结果表明,在体外发酵24、36、48、60和72 h,9%的C12∶0取代水平与不添加脂肪酸的对照相比可抑制总产气量的18.8%(P<0.01),且不受日粮类型的影响(P>0.05),发酵结束时(72 h),对瘤胃液pH值,氨氮浓度及干物质降解率没有显著影响(P>0.05);6%的取代水平可从48 h到72 h显著抑制两种日粮类型总产气量的13.2%;3%的取代水平始终不能显著抑制总产气量(P>0.05)。粗型料(精粗比3∶7)中添加9%的C12∶0对总产气量的抑制作用最大,比对照减少22.2%(60 h,P<0.01)。     

A comparison of commercial kit methods for assay of vitamin b(12) in ruminant blood

Five commercially available radioisotope dilution (RID) kits for assay of Vitamin B(12) were obtained for evaluation with ovine and bovine serum; also, for comparison with our laboratory's (Lab 1) RID method and the methods of two independent laboratories, one using RID and the other a microbiological method. One commercial kit was found to be suitable for both species because negligible non-specific binding occurred when extraction was performed at 100 degrees C (212 degrees F). Of the other four kits, two were found to be suitable for ovine and bovine serum provided non-specific binding of the latter was measured. This was also the case with the Lab 1 method. Two of the commercial kits were found to be unsuitable for assay of Vitamin B(12)in ruminant blood.