氨化与微贮处理甘蔗叶梢饲喂水牛试验

选用１８头水牛随机分为氨化、微贮和对照三组,每组６头,分别饲喂氨化、微贮和对照甘蔗叶,探讨不同处理甘蔗叶对水牛日增重和瘤胃内４８ｈ降解率影响。结果表明：在精料相同条件下,喂氨化甘蔗叶组水牛日增重和经济效益与对照组比较差异极显著（Ｐ＜０．０１）,微贮甘蔗叶与对照组比较差异显著（Ｐ＜０．０５）,且经过处理甘蔗叶采食量增加,粗纤维（ＣＦ）、中性洗涤纤维（ＮＤＦ）含量下降,在瘤胃内４８ｈ的干物质（ＤＭ）、粗蛋白质（ＣＰ）、中性洗涤纤维（ＮＤＦ）降解率均有不同程度提高,尤以氨化处理效果最佳。     

硼砂对绵羊氮代谢及营养物质消化的影响

本文研究了硼砂对绵羊营养物质消化率及氮代谢的影响。选择绵羊4只,采用4×4拉丁方设计,预饲期10d,试验期7d。在处理组的日粮中分别添加1g硼砂/kg、2g硼砂/kg和25mg乙酰氧肟酸/kg,结果表明,添加硼砂对日粮干物质、有机物和粗蛋白质消化率及对氮和尿素代谢均未产生影响。1g/kg日粮的硼砂添加量促进了瘤胃微生物氮合成。试验结果提示绵羊对脲酶抑制剂硼砂也存在适应性。     

日粮精粗比对泌乳奶牛养分消化的影响

选择4头安装有永久性瘤胃、十二指肠前端和回肠末端T形瘘管的荷斯坦泌乳奶牛,按4×4拉丁方设计,分别以铬染纤维和Co-EDTA为食糜固相和液相指示剂,研究精粗比约为30∶70的“高低质粗料型”日粮、30∶70的混合型高青贮日粮、50∶50的精粗料比例相当的日粮及65∶35的高精料日粮等4种日粮对瘤胃食糜稀释率及干物质(dry matter,DM)、有机物(organic matter,OM)、中性洗涤纤维(neutraldetergent fiber,NDF)和酸性洗涤纤维(acid detergent fiber,ADF)等养分进食量、十二指肠流量及消化道不同部位表观消化率的影响。结果表明:日粮精粗比显著(P<0.05)或极显著(P<0.01)影响奶牛DM、OM、NDF和ADF进食量、十二指肠流量及DM、OM和ADF瘤胃表观降解率,而对奶牛瘤胃食糜液相和固相稀释率、NDF瘤胃表观降解率及DM、OM、NDF和ADF后肠道和全消化道表观消化率没有影响(P>0.05)。     

肉牛甲烷排放影响因素的试验研究

为考察不同粗饲料类型、日粮精粗饲料比、能量摄入水平等因素对肉牛甲烷排放量的影响，从而为控制甲烷排放提供理论依据，本研究选用4头18月龄的健康肉用公牛(鲁西黄牛)，针对不同粗饲料类型、饲料精粗比和日粮能量摄入水平进行了试验，采用SF₆示踪法对甲烷排放量进行了测定。试验结果表明：SF₆示踪法可用来快速测定反刍动物的甲烷排放量；影响肉牛甲烷排放量因素的主次顺序依次为：饲料粗料类型＞饲料精粗比＞能量摄入水平；对肉牛饲喂紫花苜蓿和青贮玉米秸比饲喂稻草和干玉米秸时甲烷排放量要小；日粮中粗饲料越多，则肉牛的甲烷排放量越大；随着能量摄入水平的加大，肉牛的甲烷排放量也呈增加的趋势。     

金露梅与珠芽蓼草粉对模拟瘤胃体外发酵的影响

以6头体重35 kg左右、安装永久性瘤胃瘘管的健康羯羊为瘤胃液供体动物,用持续人工瘤胃装置(RUSITEC),基础日粮混合料为底物进行体外发酵试验,研究添加富含植物次生代谢物的金露梅与珠芽蓼草粉对瘤胃发酵的影响,以筛选天然饲料添加剂。结果表明,基础日粮中添加10%金露梅和10%珠芽蓼草粉与普通基础日粮之间,发酵液pH、甲烷、挥发性脂肪酸的产生量及干物质消失率差异均不显著(P ＞ 0.05),但有降低甲烷产量、提高干物质消化率的趋势。因此,在本试验条件下,添加10%金露梅和10%珠芽蓼草粉对瘤胃发酵的作用不显著,不适合做饲料添加剂。     

过瘤胃脂肪对晋南牛养分表观消化率及氮沉积的影响

为探究富含不饱和脂肪酸的过瘤胃脂肪对肉牛营养物质消化代谢和氮沉积的影响,本研究选用4头体重476±60 kg、年龄4.5岁、装有永久性瘤胃瘘管的晋南阉牛,以精补料和玉米青贮为基础饲粮,饲粮蛋白质按照1.15倍的维持营养需要量的85%(低)、100%(中)和115%(高)设计3个水平,并在此基础上添加干物质采食量的0%、2.5%、5.0%和7.5%的过瘤胃脂肪,采用3×4两因素设计,共形成12组饲粮组合,测定养分消化率、氮沉积率和血液生化指标。结果表明,第8组饲粮粗蛋白质(CP)的表观消化率极显著高于第2组、显著高于第3和第4组,第7和第10组显著高于第2组;第4、第7、第8、第11和第12组粗脂肪(EE)的表观消化率极显著高于第1、第2、第5、第9组,第3、第6和第10组显著高于第1、第2、第5、第9组;第8和第10组无氮浸出物(NFE)的表观消化率显著高于第11组;第8组中性洗涤纤维(NDF)的表观消化率显著高于第11组。第1、第5、第6、第8和第11组的氮沉积率显著高于第12组。第10组三酰基甘油酯酶(ATGL)活性显著高于第6组;第3、第4、第5、第2和第7组的胰岛素(INS)浓度极显著高于第8组;第1和第2组的胰高血糖素(GC)浓度显著高于第9和第11组;第7组的生长激素(GH)浓度显著高于第2、第4、第5、第9、第10和第11组。综上,在以饲粮蛋白质水平为标准前提下,过瘤胃脂肪适宜添加量为饲粮的5.0%。本研究为肉牛养殖和高档肉牛生产提供了一定的理论依据。     

两株侧耳属真菌对小麦秸秆化学组分及瘤胃消化率的影响

小麦秸秆木质素含量高,蛋白质等营养物质含量低,作为反刍家畜的粗饲料营养价值低,饲料化利用受到限制。通过室内小麦秸秆固态发酵试验,研究了两株侧耳属真菌Tf1（Pleurotussajor—c4u）和JG1（PleurotusCornucopiaeRoll）对小麦秸秆细胞壁化学组分的降解、瘤胃消化率和粗蛋白含量的影响。结果表明,经菌株JG1、Tf1和两菌复合发酵21d的小麦秸秆,木质素降解率分别为28．20％、30．78％和38．41％,纤维素降解率分别为19．26％、19．28％和26．65％;48h干物质瘤胃消化率分别比未发酵秸秆提高了38．62％、44．81％和55．89％,中性洗涤纤维（NDF）消化率分别提高了38．91％、49．00％和63．08％;粗蛋白含量分别比未发酵秸秆提高了58．60％、69．53％和72．22％。表明菌株JG1和Tf1在选择性降解木质素,改善瘤胃消化率,提高粗蛋白含量方面的优势,而且两菌株复合发酵具有协同作用,与单菌发酵相比,木质素降解率、瘤胃消化率和粗蛋白含量都明显提高。     

利用15N示踪技术研究尿素在人工瘤胃中的代谢

通过人工瘤胃短期发酵,采用4×2析因完全随机试验设计,利用15N标记尿素代替日粮粗蛋白的0%、10%、20%、40%,分别发酵24和48h,研究日粮不同尿素添加量对瘤胃发酵参数的影响及其在瘤胃中的代谢.结果表明:不同尿素添加量和发酵时间对瘤胃pH影响不显著(P＞0.05),添加尿素处理的瘤胃液氨态氮浓度在发酵48h时显...     

蛋氨酸硒对西门塔尔牛瘤胃发酵及尿嘌呤衍生物的影响

选用4头平均体重420 kg、年龄2.5岁装有永久性瘤胃瘘管的西门塔尔牛阉牛,采用4x4拉丁方设计,以混合精料和风干玉米秸秆为基础日粮,以蛋氨酸硒为硒源,在基础日粮中分别添加硒0 mg·kg-1、0.3mg·kg-1、0.6 mg·kg-1和0.9 mg·kg-1,研究蛋氨酸硒对西门塔尔牛瘤胃pH、氨态氮、VFA、营养物质降解率及尿嘌呤衍生物浓度的影响.结果表明:不同浓度硒处理间西门塔尔牛瘤胃pH、挥发性脂肪酸(VFA)和乙酸,丙酸无显著差异(P>0.05),氨态氮浓度显著低于对照(P<0.05);0.6mg·kg-1硒处理组西门塔尔牛玉米秸秆干物质(DM)、有机物质(OM)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)和豆粕DM、OM、粗蛋白质(CP)有效降解率均显著高于对照(P<0.05);0.6mg·kg-1和0.9mg·kg-1硒处理组西门塔尔牛尿囊素和尿嘌呤衍生物浓度显著高于0.3 mg·kg-1组和对照组(P<0.05);西门塔尔牛日粮以蛋氨酸硒为硒源时,硒的适宜添加浓度为0.6 mg·kg-1.     

蛋白质和过瘤胃脂肪对晋南牛瘤胃发酵和尿嘌呤衍生物的影响

为探究蛋白质和富含不饱和脂肪酸的过瘤胃脂肪对瘤胃发酵和尿嘌呤衍生物的影响,选用4头装有永久性瘤胃瘘管的晋南阉牛,按照蛋白质需要量的85%、100%和115%设计3个水平,并在此基础上添加0、2.5%、5.0%和7.5%的亚麻油制作的钙皂作为过瘤胃脂肪,采用3×4两因素设计,共形成12组饲粮组合,测定瘤胃pH、氨态氮浓度(NH_3-N)浓度、挥发性脂肪酸(VFA)含量以及尿嘌呤衍生物(PD)的排出量。结果表明,蛋白质和过瘤胃脂肪水平对瘤胃pH均无显著影响。蛋白质水平对NH_3-N浓度影响显著,9组NH_3-N显著高于1、2、3、4和8组,10组显著高于3和8组;对丙酸和乙酸、丁酸、乙酸/丙酸及总酸分别具有极显著和显著影响,5组的乙酸浓度较1、2、3和4组显著提高,9、10和11组瘤胃液中的丙酸浓度较1和2组显著提高,12组较2组显著提高,10组的丁酸浓度显著高于7和8组,1和2组的乙酸/丙酸比值显著高于9、10和11组;对精补料养分有效降解率影响极显著,对秸秆有机物(OM)和酸性洗涤纤维(ADF)分别具有极显著和显著影响,10组精补料粗蛋白质(CP)瘤胃有效降解率显著高于2、3、4、5、6、7和8组,1、9、11和12组显著高于4、5、6、7和8组;对玉米秸秆中ADF瘤胃有效降解率6、7和8组显著高于除5和12组之外的其余各组,5和12组显著高于除9和11组之外的其余各组;对尿囊素和尿嘌呤衍生物有显著影响,12组的尿囊素和尿嘌呤衍生物显著高于1和4组,11组尿酸显著高于其余组。综上,饲粮蛋白质水平对瘤胃发酵和尿嘌呤衍生物具有显著影响,饲粮蛋白质水平为饲养标准需要量前提下,过瘤胃脂肪适宜添加量为饲粮的5%。本研究结果为肉牛养殖中日粮过瘤胃脂肪添加量及蛋白质水平提供了一定的依据。     

碳氮源对复合木质素降解菌木质素降解能力及相关酶活的影响

白腐真菌所具有的降解木质素能力源于其所产生的酶系统,碳源和氮源是其降解木质素和产酶的一个极为重要的影响因素。通过室内小麦秸秆固态发酵试验,研究了不同的碳、氮源对两株侧耳属真菌Tf1（P.pulmonarius）和JG1（P.cornucopiae）产酶活力、木质素降解和粗蛋白含量的影响。结果表明,Lip和MnP是参与复合木质素降解菌Tf1＋JG1降解小麦秸秆重要的木质素降解酶。以葡萄糖为碳源,酒石酸铵为氮源能显著提高复合木质素降解菌对木质素的降解能力,发酵9 d后小麦秸秆的失重率为14.87%,木质素含量为8.68%,木质素降解率为22.95%;粗蛋白含量为7.28%,比未发酵麦秸提高了36.84%（P〈0.05）;Lip和MnP活力分别为629.11 U.g-1和622.22 U.g-1。     

Effect of wheat-based dried distillers' grains with solubles inclusion on barley-based feed chemical profile, energy values, rumen degradation kinetics, and protein supply

The objectives of this study were to determine the effect of replacing the barley grain portion of the diet by wheat-based dried distillers' grains with solubles (wDDGS) at graded levels on feeding value for beef cattle. Two cultivars of barley were mixed with two sources of wDDGS in ratios of 100:0, 75:25, 50:50, and 25:75% (weight DM basis; denoted B0, B25, B50, and B75, respectively). This study revealed that increasing wDDGS inclusion level increased most of the nutritional composition linearly except for starch, which linearly decreased (from 609 to 320 g/kg of DM). Soluble, slowly degradable, and undegradable Cornel Net Carbohydrate and Protein System (CNCPS) protein and carbohydrate fractions linearly increased with increasing wDDGS inclusion level, whereas their rapidly and intermediately degradable fractions decreased. With increasing wDDGS inclusion, the rumen degradation rate of all measured parameters decreased linearly, the extent of degradability of organic matter was not affected, and the extent of CP degradability (g/kg DM) as well as the predicted protein supply in the small intestine and degraded protein balance in the rumen was increased. The inclusion of wDDGS in barley-based diets up to 50% did not alter energy values of the diet. Furthermore, optimum N to energy balance of the feed mixture for microbial growth in the rumen was reached by replacing 25% of barley by wDDGS. Thus, the nutritive value of the barley-based diets is manipulated by including wDDGS, which can be used to overcome the shortcomings of barley-dominated diets for beef cattle.     

Comparative study of crude and purified cellulose from wheat straw

A sequential totally chlorine-free procedure for isolation of cellulose from wheat straw was proposed in this study. The dewaxed straw was pretreated with 0.5 M NaOH in 60% methanol at 60 degrees C for 2.5 h under ultrasonic irradiation for 0-35 min and sequentially posttreated with 2% H(2)O(2)-0.2% TAED at pH 11.8 for 12 h at 48 degrees C, which together solubilized 85.3-86.1% of the original hemicelluloses and 91.7-93.2% of the original lignin, respectively. The yield of crude cellulose ranged between 46.2 and 49.2% on a dry weight basis related to wheat straw, which contained 11.2-12.2% residual hemicelluloses and 2.5-2.9% remaining lignin. Further treatment of the corresponding crude cellulosic preparations with 80% acetic acid-70% nitric acid under the condition given yielded 36.8-37.7% of the purified cellulose, which contained minor amounts of bound hemicelluloses (2.5-2.8%) and was relatively free of associated lignin (0.1-0.2%). The isolated crude and purified cellulose samples were comparatively studied by FT-IR and CP/MAS (13)C NMR spectroscopy, and the relative crystallinity was also estimated. The final stage treatment with 80% acetic acid-70% nitric acid decreased the hemicelluloses and lignin associated in the crude cellulose but led to 3.1-5.4% degradation of the original cellulose; in addition, the purity of the obtained cellulose was high. However, it was found that the final stage treatment is not severe enough to cause decrystallization of cellulose. The thermal stability of the purified cellulose is higher than that of the corresponding crude cellulose.     

高效木质纤维素分解菌群筛选及其酸碱调节能力研究

为获得能够改良土壤酸碱性的微生物群体, 以混合堆放牛粪、鸡粪的储粪池外围土样为材料, 采用限制培养技术筛选了一组木质纤维素分解菌群, 并对该菌群在不同初始pH下的适应能力和纤维材料的分解能力及其耐盐特性进行了研究。结果表明: 以不同碳源(滤纸、玉米秸秆、稻草秸秆和小麦秸秆)制作不同初始pH(5.0~11.0)的培养基, 接种木质纤维素分解菌群后培养基pH均迅速向中性变化, 第3 d集中至8.0左右, 6 d后稳定至7.8~8.6; 7 d内滤纸、玉米秸秆、稻草秸秆和小麦秸秆失重率分别超过93.15%、50.53%、44.29%和42.60%; 以滤纸为惟一碳源、NaCl浓度2.0%的培养基接种, 7 d滤纸失重率达84.82%。木质纤维素分解菌群具有较强的适应及调节pH能力, 且能够高效分解木质纤维材料, 并具有一定的耐盐特性, 可见该菌群在酸碱土壤酸碱性改良领域具有一定开发潜力。     

中国农作物秸秆饲料化利用满足度和优势度分析

农作物秸秆饲料化利用作为农作物秸秆利用途径之一,为奶牛、肉牛和肉羊饲养提供充足的粗饲料,能保障“节粮型”畜牧业的发展。该文以中国31个省市的农作物秸秆饲料为研究对象,对2008－2013年各省市农作物秸秆饲料化利用量、反刍动物农作物秸秆饲料需求量进行计算,并求出农作物秸秆饲料化满足度和优势度。结果表明：1）2008－2013年,中国农作物秸秆饲料化利用量和反刍动物农作物秸秆饲料需求量均呈现增长趋势,2013年分别达到16895.12和12568.36万t。东北地区、黄淮海地区、长江中下游地区和六大牧区中内蒙古和四川为农作物秸秆饲料化利用量高的地区。东北地区、黄淮海地区、西南地区和六大牧区中内蒙古、四川、西藏、甘肃和新疆为反刍动物农作物秸秆饲料需求量多的地区。2）2008－2013年,中国农作物秸秆饲料化满足度呈波动增长的趋势,2013年满足度达到了134.43%,意味着从全国范围来看,农作物秸秆饲料化利用量满足反刍动物秸秆饲料需求,但呈现“东高西低”情况。六大农区中的黄淮海地区和东北地区、六大牧区中的内蒙古和四川农作物秸秆饲料化利用与其他地区相比更具有优势。3）六大农区中的黄淮海地区和东北地区、六大牧区中的内蒙古和四川为农作物秸秆饲料化利用发展核心地区。该研究为分析中国“节粮型”畜牧业发展现状提供基础资料。     

Cool‐Season annual legume effects on wheat forage nutritive value

Hard red winter wheat (Triticum aestivum L. emend. Thell.) is an important cool‐season winter forage used primarily for increasing weight gain on growing beef cattle in the southern Great Plains. ‘Karl’ hard red winter wheat grown alone or grown with either hairy vetch (Vicia villosa Roth) or pea [(Pisum sativum L. subsp. arvense) var. ‘Austrian winter'] was sampled for forage nutritive value. The interplanted legume forage was also sampled for forage nutritive value. Ruminally degradable nitrogen (RDN):ruminally degradable organic matter (RDOM) ratios were highest for legume forage and exceeded the National Research Council (NRC) recommendation of 26.13 g RDN: 1 kg RDOM for peak ruminai microbial efficiency during March, April, and May sample periods over the 2‐year study. Wheat grown alone met the NRC requirement only during March. Wheat grown with either hairy vetch or pea had higher (P<0.05) RDN:RDOM ratios and crude protein (CP) values when compared to wheat grown alone during May. There were no differences (P>0.05) in dry matter (DM) yield between wheat grown alone or grown with the legumes except when analyzed by individual date, and then only for 1 of 6 sample dates. Undegraded intake protein (UIP) was generally higher (PO.05) for wheat compared to the legumes and higher (PO.05) for wheat grown alone during May compared to wheat grown with the legumes during May. The decline of the RDN:RDOM values to 40% below the NRC recommendation of wheat grown alone during May indicates a possible need for protein supplementation for growing beef cattle grazing wheat during this period. These data also indicate that interplanting legumes with wheat may enhance animal performance by providing forage of higher nutritive value. More information regarding grazing tolerance of these selected cool‐season annual legumes and subsequent animal performance is required.     

Nitrogen and carbon mineralization of surface-applied and incorporated winter wheat and peanut residues

Laboratory incubation experiments were conducted to study the C and N mineralization dynamics of crop residues (fine roots and straw) of the two main crops (winter wheat and peanut) in the Chinese Loess Plateau under different ways of incorporation. The C mineralization patterns of the soil amended with winter wheat residues differed greatly, and the highest C mineralization was observed in the treatment with winter wheat straw incorporated (39% of the total added C mineralized). The way of straw placement had only a minor effect on the pattern of C mineralization for peanut. Generally, winter wheat residues showed a stronger immobilization than peanut residues during the incubation period, without any net N release. Winter wheat straw incorporated showed the strongest N immobilization with 35 mg kg⁻¹ (equivalent to 27% of added N) immobilized at the eighth week. This study indicated that retaining crop residues at the soil surface in the dry land soils of the Chinese Loess Plateau is beneficial for C sequestration. It also showed that N immobilization occurs only during a limited period of time, sufficient to prevent part of the mineral N pool from leaching, and that net N mineralization can be expected during the subsequent cropping season, thus enhancing synchronization of N supply and demand.     

小麦秸秆的氨化厌氧发酵工艺及影响因素研究

为了提高小麦秸秆的产气效率,利用4.5%的尿素对其进行氨化预处理,并将预处理后的秸秆进行厌氧发酵,分别研究了氨化时间对预处理效果的影响及在不同温度和原料组分配比下的氨化厌氧发酵过程。结果表明：氨化预处理20d后的秸秆COD溶出量与未添加预处理剂相比增加了95.43%,VS增加9.07%,在第15d时已达20d溶出总量的94.61%,采用扫描电镜（SEM）及视频光学接触角扫描仪（GBX）观察发现,氨化15d已可有效破坏秸秆的纤维结构,增加表面亲水性能;在预处理后的发酵实验中,中温发酵（35℃）显现出明显的产气优势,经40d厌氧发酵TS产气率可达193.8mL.g-1;当发酵原料组分配比为秸秆：牛粪：污泥=1：0.5：0.5（干物质质量比）时,其厌氧发酵的累积产气量最大,达6505mL。