不同精粗比日粮对绵羊瘤胃内纤维素酶活的影响

选取9只体况良好,带有永久性瘤胃瘘管的内蒙古半细毛羯羊,设三个不同精粗比,10∶90、30∶70、40∶60,二种待测粗饲料(麦秸和玉米秸)组成3×2因子试验,测定其CMCase活性。研究结果表明,不同精粗比日粮显著或极显著地影响着纤维素酶活(P<0 05或P<0 01)。其中平均纤维素酶活在30∶70时最高,其次为10∶90,最后为40∶60。不同饲料之间PAM的纤维素酶活差异显著,且两种饲料到达最大纤维素酶活的时间不同,麦秸为60h,玉米秸为48h。     

阿魏酸酯酶处理对羊草、玉米秸、稻秸及麦秸瘤胃体外发酵特性的影响

为了分析评价阿魏酸酯酶在瘤胃微生物降解利用秸秆等木质纤维性饲料中的功效,本研究采用短期人工瘤胃体外发酵试验,结合发酵产气自动记录技术,研究了在羊草、玉米秸、稻秸及麦秸4种不同粗饲料中添加2%比例阿魏酸酯酶39℃预处理16 h后对72 h瘤胃微生物发酵的影响.结果表明,加酶前后干物质消失率差异不显著(P>0.05);在添加阿魏酸酯酶后,总挥发性脂肪酸(TVFA)产生量由高至低依次为羊草、稻秸,玉米秸、麦秸;与对照组相比,添加阿魏酸酯酶后TVFA增幅由高至低依次为麦秸(+13.9%)、玉米秸(+13.6%)、羊草(+7.6%)、稻秸(+3.0%)(P<0.05).此外,添加阿魏酸酯酶亦可显著提高羊草和麦秸的体外发酵产气量(42.2%和16.6%),麦秸体外发酵产气速率提高37.5%(P<0.05).用阿魏酸酯酶预处理农作物秸秆等粗饲料,可促进瘤胃微生物对饲料细胞壁的降解,为今后进一步通过开展动物饲养试验来研究和开发酯酶的饲用价值提供了实践指导依据.     

粗饲料体外发酵特性及对微生物细胞膜界面物理化学特性的影响

本试验旨在研究不同来源粗饲料发酵特性及对微生物细胞膜界面物理化学特性的影响。以小麦秸、玉米秸、水稻秆、苜蓿和桂牧一号为试验材料,采用体外发酵技术,研究不同粗饲料发酵48 h时体外发酵特性及发酵液微生物界面物理化学特性。结果表明:1)5种粗饲料体外发酵产气量及产气动力学参数[最大产气量(Vf)、产气曲线常数(b)、产气分率(k)、达到最大产气量1/2时所用时间(T0.5)、初始发酵产气分率(FRD0)和达到最大产气量1/2时的发酵产气分率(FRDt0.5)]存在差异;Vf以桂牧一号最高,显著高于水稻秆(P0.05),极显著高于小麦秸(P0.01);b、k及T0.5以小麦秸最高,T0.5按小麦秸水稻秆玉米秸和桂牧一号苜蓿的顺序显著降低(P0.05);苜蓿的FRD0和FRDt0.5显著或极显著高于桂牧一号、水稻秆和玉米秸(P0.05或P0.01)。2)苜蓿干物质消失率显著或极显著高于水稻秆、小麦秸(P0.05或P0.01),氨态氮含量显著高于桂牧一号、水稻秆(P0.05)。不同粗饲料间发酵液微生物细胞膜通透性按玉米秸小麦秸水稻秆桂牧一号和苜蓿的顺序显著降低(P0.05)。由此可见,不同品种粗饲料间在发酵特性以及微生物部分界面物理化学特性间存在差异,利用不同粗饲料发酵不同步的特性进行组合,可能有利于提高粗饲料的利用。     

常用饲料原料干物质及蛋白质在大足黑山羊瘤胃内降解规律的研究

选用4头体重相近的安装有永久性瘤胃瘘管的周岁大足黑山羊阉羊,采用瘤胃尼龙袋法,测定常用的3类17种饲料原料干物质及蛋白质在瘤胃内的有效降解率。结果表明:干物质有效降解率由大到小的顺序为小麦、玉米、大米、高粱、麸皮、豆粕、菜粕、棉粕、玉米酒糟、花生秸、苜蓿干草、鱼粉、玉米秸、小麦秸、稻草、棉花秸、稻谷壳,蛋白质有效降解率由大到小的顺序为麸皮、小麦、玉米、大米、高粱、苜蓿干草、花生秸、玉米酒糟、豆粕、棉粕、菜粕、鱼粉、玉米秸、小麦秸、稻草、棉花秸、稻谷壳。     

瘤胃能氮平衡原理对我国农村奶牛饲养的指导意义

我国北方地区,广大奶农对粗饲料重视不足,加上技术设备落后和客观经济条件的制约,实践中普遍存在缺乏优质粗饲料的问题,致使奶牛生产性能不高、乳脂率偏低、消化道疾患增加,限制了奶畜生产潜力的发挥,继而影响经济效益。在这种生产模式下,粗饲料往往为秸秆类饲料,如小麦秸、玉米秸、高粱秸和稻草等,粗饲料的瘤胃可降解性差：同时,蛋白质饲料多是杂粕,     

化学处理对秸秆秕壳的瘤胃有机物降解率的影响

用3头带瘤胃瘘管的杂交肉丰测定谷草、稻草、玉米秸、糜黍秸、莜麦秸、麦秸、荞麦秸、麦壳、白薯蔓、苜蓿秸、花生壳、豆荚的未经处理、尿素氯化处理、(尿素+石灰)复合化学处理的有机物瘤胃动态降解率(％)分别为51.03、52.28、55.64;34.34、42.74、48.32;39.62、48.93、49.54;44.86、50.16、55.03;33.89、44.00、48.45;31.70、44.63、46.09;47.19、58.13、59.84;34.75、41.91、42.98;56 01、56.97、55.52;32.66、32.88、34.41;14.85、16.17、16.48;40.79、41.48、45.34。除谷草、白薯蔓、苜蓿秸、豆荚外,经氨化及复合化学处理后均能显著提高有机物的瘤胃动态降解率(P<0.05),且处理后稻草、玉米秸、麦秸的不同结构碳水化合物也发生明显变化,瘤胃动态降解率与不同结构碳水化合物含量有高度相关(R=0.82)。     

绵羊全混日粮体外培养产气量的动态研究

本实验根据育肥羊营养配方，在机械性能良好，饲料配方准确的情况下，研究了麦秸、玉米秸、苜蓿之间不同比例的粗饲料组合与精料之间不同配比的组合效应，通过Menke的体外瘤胃发酵体系，测定不同底物的0、1、2、4、8、12、24体外产气量（GP），从瘤胃消化降解层面上探讨饲草型全混日粮对绵羊体外产气量的影响，以产气量为指标评定了混合日粮的发酵特性，进而筛选出最佳配比的全混日粮。结果表明：精粗比不同时，玉米秸十苜蓿＋精料的配比产气量最高，小麦秸＋苜蓿＋精料的配比产气量较低；通过综合比较，玉米秸：苜蓿：精料=3：1：6产气量最高，为最佳配比。     

7种粗饲料常规营养成分及其在山羊瘤胃液降解特性的研究

研究7种粗饲料(玉米秸秆、玉米青贮、甜菜颗粒、麦秸、大豆皮、燕麦草和苜蓿青贮)的常规营养成分差异及其在山羊瘤胃液的降解特性,为粗饲料在山羊生产中的有效利用提供理论依据。选取4只12月龄,体质量相近[(50±2.0) kg],安装永久性瘤胃瘘管的山羊作为瘤胃液供体动物。采用ANKOM DAISYⅡ技术进行饲料的体外瘤胃降解。然后分别测定样品的干物质(DM)、中性洗低纤维(NDF)和酸性洗涤纤维(ADF)的瘤胃降解特性,及瘤胃发酵参数(NH_3-N、VFA)。结果表明：7种粗饲料原料中苜蓿青贮粗蛋白(CP)和粗脂肪(EE)含量显著高于其余粗饲料(P<0.05);麦秸的粗灰分(ASH)含量最高(P<0.05);玉米秸秆的ADF和NDF含量最高(P<0.05)。DM有效降解率大小顺序依次为玉米青贮>苜蓿青贮>甜菜颗粒>燕麦草>大豆皮>麦秸>玉米秸秆;NDF有效降解率大小顺序依次为苜蓿青贮>甜菜颗粒>玉米青贮>燕麦草>大豆皮>麦秸>玉米秸秆;ADF有效降解率大小顺序依次为苜蓿青贮>甜菜颗粒>玉米青贮>燕麦草>大豆皮>麦秸>玉米秸秆。48 h玉米秸秆的NH_3-N含量显著高于其余粗饲料(P<0.05),48 h玉米青贮、甜菜颗粒和苜蓿青贮NH_3-N含量显著低于其余粗饲料(P<0.05),但三者差异不显著(P>0.05)。玉米青贮TVFA含量显著高于其余粗饲料(P<0.05),其次为甜菜颗粒和燕麦草。说明7种粗饲料营养成分、瘤胃降解特性均存在差异,其中,玉米青贮、苜蓿青贮和甜菜颗粒的可利用价值较高,大豆皮和燕麦草的可利用价值居中,麦秸和玉米秸秆的可利用价值低。     

体外发酵技术研究秸秆粗饲料营养价值及降解特性

为了探究粗纤维饲料对反刍动物的营养特性,本试验研究了2种农作物秸秆(稻秸,麦秸)的发酵特性和动态降解率。试验分3组(稻秸组,麦秸组,混合组:50%稻秸+50%麦秸),采用瘤胃体外发酵技术,测定粗饲料的发酵参数变化。结果表明:三种粗饲料累计产气量和干物质(DM)降解率均随时间延长而增加,产气和DM降解主要集中在12~48 h。发酵12 h时,麦秸组和混合组累计产气量显著高于稻秸组(P0.05),麦秸组和混合组差异不显著。发酵24 h时,麦秸组累计产气量显著高于稻秸组和混合组(P0.05),稻秸组和混合组差异不显著。发酵36~72 h时,累计产气量均呈现麦秸组混合组稻秸组(P0.05)。发酵24 h时,稻秸组干物质降解率、中性洗涤纤维(NDF)降解率、发酵液中氨态氮(NH4-N)浓度均显著高于麦秸组和混合组(P0.05),乙酸浓度显著高于麦秸组(P0.05),而菌体蛋白(MCP)浓度呈现麦秸组混合组稻秸组(P0.05)。发酵48 h时,麦秸组乙酸浓度与酸性洗涤纤维(ADF)降解率均显著高于稻秸组和混合组(P0.05)。发酵72 h时,麦秸组ADF降解率显著高于混合组和稻秸组(P0.05)。结果提示,禾本科粗饲料在瘤胃内降解规律基本一致,主要发生在12~48 h,稻秸DM、NDF、ADF降解高峰期要早于麦秸及二者混合,稻秸的营养价值略高于麦秸。     

底物类型及含水量对瘤胃真菌固体发酵产酶活性的影响

试验采用二因素试验设计,研究不同底物类型及含水量对瘤胃真菌固态发酵产纤维素酶活的影响。发酵底物粗料类型分别为菌糠、花生蔓和玉米秸,含水量分别为30%、40%、50%和60%。试验进行10 d,每2 d取发酵样品测试,监测其中的羧甲基纤维素酶、微晶纤维素酶、β-葡萄糖苷酶和滤纸酶的酶活。试验结果表明:在菌糠、花生蔓及玉米秸3种粗料底物中,花生蔓效果最好,可显著提高羧甲基纤维素酶、微晶纤维素酶和β-葡萄糖苷酶酶活(P0.05)。含水量对纤维素酶活影响明显,含水量为40%时对羧甲基纤维素酶、微晶纤维素酶、β-葡萄糖苷酶和滤纸酶酶活均有显著影响(P0.05)。不同底物类型与含水量的互作对4种酶的酶活影响显著(P0.05)。滤纸酶发酵8 d达到峰值,羧甲基纤维素酶、微晶纤维素酶和β-葡萄糖苷酶均为发酵4~6 d时酶活最高。综合各试验因素,试验以花生蔓为底物粗料,含水量40%,培养发酵4~6 d,纤维素酶活最佳。     

Amino acid profiles of rumen undegradable protein: a comparison between forages including cereal straws and alfalfa and their respective total mixed rations

Optimizing the amino acid (AA) profile of rumen undegradable protein (RUP) can positively affect the amount of milk protein. This study was conducted to improve knowledge regarding the AA profile of rumen undegradable protein from corn stover, rice straw and alfalfa hay as well as the total mixed ratio diets (TMR) based on one of them as forage source [forage‐to‐concentrate ratio of 45:55 (30% of corn stover (CS), 30% of rice straw (RS), 23% of alfalfa hay (AH) and dry matter basis)]. The other ingredients in the three TMR diets were similar. The RUP of all the forages and diets was estimated by incubation for 16 hr in the rumen of three ruminally cannulated lactating cows. All residues were corrected for microbial colonization, which was necessary in determining the AA composition of RUP from feed samples using in situ method. Compared with their original AA composition, the AA pattern of forages and forage‐based diets changed drastically after rumen exposure. In addition, the extent of ruminal degradation of analysed AA was not constant among the forages. The greatest individual AA degradability of alfalfa hay and corn stover was Pro, but was His of rice straw. A remarkable difference was observed between microbial attachment corrected and uncorrected AA profiles of RUP, except for alfalfa hay and His in the three forages and TMR diets. The ruminal AA degradability of cereal straws was altered compared with alfalfa hay but not for the TMR diets. In summary, the AA composition of forages and TMR‐based diets changed significantly after ruminal exposure, indicating that the original AA profiles of the feed cannot represent its AA composition of RUP. The AA profile of RUP and ruminal AA degradability for corn stover and rice straw contributed to missing information in the field.     

山东省羊常用粗饲料营养价值评定

试验旨在综合评价从山东省17个市采集的羊常用粗饲料原料的营养价值。试验测定了109个样本10种常用原料的常规营养成分及总能(GE),应用两级离体消化法测定干物质消化率(IVDMD),以计算消化能(DE)和代谢能(ME),并根据预测干物质随意采食量(DMI),进而计算出分级指数(GI)。结果表明,不同粗饲料间的常规养分的差异不能准确地评价饲料营养价值;以NDF、ADF所得GI综合评价粗饲料中营养价值得到苜蓿>冬牧70>地瓜秧>羊草>花生秧>青贮玉米秸>玉米秸>水稻秸>豆秸>麦秸;IVDMD与NDF、ADF均呈显著负相关,而与CP呈显著正相关;DE与NDF、ADF相关性较强,且均呈负相关。     

青海省农牧交错区牦牛12种常用粗饲料营养参数的测定

本研究结合常规营养成分分析和体外发酵产气技术,主要测定了青海省农牧交错区的农作物秸秆(小麦秸秆、豌豆秸秆、蚕豆秸秆、油菜秸秆及马铃薯秸秆)、优质补饲饲草(青贮玉米秸、苜蓿青干草、燕麦青干草)和天然草地型(线叶嵩草、高山柳+黑褐苔草、金露梅—珠芽蓼及藏嵩草)冷季牧草等牦牛12种常用粗饲料的常规营养成分及体外发酵产气参数等营养评价指标,结果表明,5种农作物秸秆除豌豆秸秆和蚕豆秸秆的粗蛋白质含量分别为8.5%、9.75%,其余秸秆均低于8%,有机物质消化率在40%～65%,代谢能在4.0～9.0MJ/kg;4种天然草地型冷季牧草的粗蛋白质均低于8%,有机物质消化率在48%～70%,代谢能在6.0MJ/kg～10.0MJ/kg的范围内;3种优质补饲饲草苜蓿青干草、燕麦青干草和青贮玉米秸的粗蛋白质含量分别为11.36%、8.79%、5.25%,有机物质消化率在42%～70%,代谢能在5.0～11.0MJ/kg。     

不同精粗比日粮对围产期奶牛健康状况的影响

本试验研究了不同精粗比日粮对奶牛血液pH、尿液pH、采食量及产后瘫痪、胎衣不下、产褥热等健康指标的影响。选择10头预产期相同,体重、体况相近的中国荷斯坦奶牛,随机分为2组,试验1组(CS组)饲喂以玉米秸秆为粗饲料来源的日粮,日粮精粗比接近6:4;试验2组(MF组)饲喂以羊草、苜蓿和玉米青贮为粗饲料来源的日粮,日粮精粗比接近4:6。试验结果显示,CS处理组奶牛产前、产后干物质采食量均极显著高于MF组(P<0.01),且CS处理组奶牛产后干物质采食量增长较快、幅度较大。另外,试验结果还发现,MF处理组尿液pH显著高于CS处理组(P<0.05),两处理组奶牛产前、产后血液pH没有差异(P>0.05)。此外,MF处理组产后疾病的发生率显著高于CS组。试验结果表明,围产期奶牛饲喂精料水平较高的日粮对奶牛产后的健康状况更加有利。     

奶牛常用饲草的体外发酵CH4产量研究

为研究不同饲草对反刍动物甲烷(CH4)排放量的影响,利用虚拟仪器技术设计的体外发酵产气自动记录系统,结合气相色谱仪,测定了奶牛业常用饲草体外发酵72 h后的发酵指标。结果表明:发酵72 h后,供试饲草的CH4产量介于56.85～74.63 mL.g-1DMloss,最高的为玉米(Zea mays L.)秸秆,最低的为苜蓿(Medicagosativa L.)干草Ⅰ。体外发酵程度由高到低依次为青贮玉米、苜蓿干草Ⅰ、苜蓿干草Ⅱ、羊草(Leymus chinensis T.)干草、苜蓿茎秆、玉米秸秆。各饲草的产气动态均呈指数函数变化,趋势相似,在0～24 h内累计产气量迅速增加,24～36 h内增长速率渐缓,36 h以后速率趋于平缓。各饲草的CH4产量与其中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)含量成显著正相关(P<0.05),与其粗蛋白(CP)含量成极显著负相关(P<0.01);通过逐步回归分析,建立常规养分含量与CH4产量的回归模型:PCH4=60.02-0.91×CP+0.44×ADF(R2=0.96)。综上表明,饲草的CH4产量与其品质有关,优质饲草体外发酵程度高,CH4产量低,从而提高饲料利用率、减少温室效应,而劣质饲草则相反。     

饲草组合效应综合指数研究

依据组合效应综合指数(MFAEI)理论,以饲草的营养评价为基础,结合肉羊育肥营养需求特点,采用体外法,测定苜蓿、番茄皮渣、玉米秸与小麦秸不同组合的pH值、24 h累积产气量(GP)、有机物质降解率(IVDOM)、微生物蛋白产生量(MCP)、挥发性脂肪酸产量(VFA),并结合MFAEI筛选出4组最优饲草配方,即苜蓿/番茄渣/玉米秸=30/10/60,此配方多项组合效应值0.80;苜蓿/玉米秸=50/50,此配方多项组合效应值0.85;苜蓿/番茄渣/小麦秸=30/20/50,此配方多项组合效应值0.82;苜蓿/小麦秸=60/40,多项组合效应值0.78,以最大限度地发挥饲草间的正组合效应,控制和消除饲料间的负组合效应,从而最大限度地发挥草食家畜的生产性能,降低饲养成本。     

Comparison of in vitro and in situ methods in evaluation of forage digestibility in ruminants

The objective of this study was to compare the application of different in vitro and in situ methods in empirical and mechanistic predictions of in vivo OM digestibility (OMD) and their associations to near-infrared reflectance spectroscopy spectra for a variety of forages. Apparent in vivo OMD of silages made from alfalfa (n = 2), corn (n = 9), corn stover (n = 2), grass (n = 11), whole crops of wheat and barley (n = 8) and red clover (n = 7), and fresh alfalfa (n = 1), grass hays (n = 5), and wheat straws (n = 5) had previously been determined in sheep. Concentrations of indigestible NDF (iNDF) in all forage samples were determined by a 288-h ruminal in situ incubation. Gas production of isolated forage NDF was measured by in vitro incubations for 72 h. In vitro pepsin-cellulase OM solubility (OMS) of the forages was determined by a 2-step gravimetric digestion method. Samples were also subjected to a 2-step determination of in vitro OMD based on buffered rumen fluid and pepsin. Further, rumen fluid digestible OM was determined from a single 96-h incubation at 38°C. Digestibility of OM from the in situ and the in vitro incubations was calculated according to published empirical equations, which were either forage specific or general (1 equation for all forages) within method. Indigestible NDF was also used in a mechanistic model to predict OMD. Predictions of OMD were evaluated by residual analysis using the GLM procedure in SAS. In vitro OMS in a general prediction equation of OMD did not display a significant forage-type effect on the residuals (observed - predicted OMD; P = 0.10). Predictions of OMD within forage types were consistent between iNDF and the 2-step in vitro method based on rumen fluid. Root mean square error of OMD was least (0.032) when the prediction was based on a general forage equation of OMS. However, regenerating a simple regression for iNDF by omitting alfalfa and wheat straw reduced the root mean square error of OMD to 0.025. Indigestible NDF in a general forage equation predicted OMD without any bias (P ≥ 0.16), and root mean square error of prediction was smallest among all methods when alfalfa and wheat straw samples were excluded. Our study suggests that compared with the in vitro laboratory methods, iNDF used in forage-specific equations will improve overall predictions of forage in vivo OMD. The in vitro and in situ methods performed equally well in calibrations of iNDF or OMD by near-infrared reflectance spectroscopy.     

The effect of forage source and particle size on finishing yearling steer performance and ruminal metabolism.

Two finishing trials and a metabolism trial were conducted to evaluate the effect of forage source and particle size in dry-rolled corn finishing diets. In Exp. 1, 224 crossbred yearling steers (BW = 342+/-11 kg) were used in a randomized complete block design consisting of seven treatments. Treatments were an all-concentrate diet or diets containing equal NDF levels provided by alfalfa hay or wheat straw (three treatments each) with each forage source ground to pass through a .95-, 7.6-, or 12.7-cm screen. Steers fed diets containing forage had greater (P < .05) DMI than steers fed an all-concentrate diet. Steers fed alfalfa diets gained faster (P < .05) with a greater (P < .05) concentrate efficiency than steers fed either all-concentrate or straw diets. In Exp. 2, 120 crossbred yearling steers (BW = 307+/-2 kg) were used in a completely randomized design and fed dry-rolled corn diets containing 10% alfalfa ground to pass through either a .95- or 7.6-cm screen. Alfalfa particle size had no effect on performance or carcass measurements. In Exp. 3, six ruminally fistulated steers (BW = 508+/-34 kg) were used in a 6 x 6 Latin square design and fed an all-concentrate diet or diets containing equal NDF levels provided by alfalfa hay, wheat straw, or ground corncobs with alfalfa and straw ground to pass through either a 2.54- or 12.7-cm screen. Steers fed straw diets spent more time (P < .10) chewing than those receiving the other diets. In conclusion, forage particle size had no effect on finishing cattle performance or ruminal metabolism data. However, cattle consuming different forage sources in dry-rolled corn finishing diets may not respond similarly in animal performance.     

添加物料和菌剂对日喀则地区马铃薯茎叶青贮品质的影响

以日喀则地区马铃薯(Solanum tuberosum)茎叶为原料制作青贮饲料,分别与玉米(Zea mays)面、小麦(Triticum aestivum)麸、聚合草(Symphytum officinale)、紫花苜蓿(Medicago sativa)、青饲玉米、燕麦草(Arrhenatherum elatius)、干青稞(Hordeum vulgare)秸秆、干油菜(Brassica napus)壳等材料混贮,以甲酸、尿素、食盐和6种生物菌剂(A,活性乳酸菌冻干粉;B,益加益秸秆发酵剂;C,千牧EM菌原种;D,百益宝EM菌种;E,微特美益生菌种;F,粗饲料降解剂)为添加剂,聚乙烯袋真空包装分别于发酵30、60、90d后进行感官评定及生化分析,采用隶属函数法综合评价青贮品质。结果表明,日喀则地区马铃薯茎叶青贮饲料在制作后30d已经基本完成发酵进入青贮稳定阶段,能长期有效保持饲料的水分及营养物质。单独的马铃薯茎叶青贮效果差,添加生物菌剂、甲酸、麦麸、玉米面、青饲玉米秸秆、燕麦草可以改善青贮品质,其中添加麦麸的效果优于玉米面,添加青饲玉米优于添加燕麦草。聚合草含水量高、紫花苜蓿营养丰富,但是与马铃薯茎叶混贮发酵效果差。干油菜壳不适于与马铃薯茎叶混贮。菌剂A、B的青贮效果要优于E、F。研究得出,马铃薯茎叶+30%麦麸,马铃薯茎叶+0.3%尿素+0.4%食盐+30%麦麸+D,茎叶+30%麦麸+B这3个青贮处理效果较好。     

粗饲料组合对奶牛饲粮养分消化率、能量和氮的利用的影响

本试验旨在研究粗饲料组合对奶牛饲粮养分消化率、能量和氮的利用的影响。试验采用单因素随机区组设计,将 １６头体重、年龄、胎次相近的,处于干奶期的健康荷斯坦奶牛分为 ４组,每组 ４头。以常用的粗饲料设计 Ａ（玉米青贮 ＋玉米秸秆）、Ｂ（玉米青贮 ＋羊草）、Ｃ（玉米青贮 ＋玉米秸秆 ＋羊草）、Ｄ（玉米青贮 ＋苜蓿草 ＋羊草）４种粗饲料组合的饲粮。结果表明：饲粮Ｄ干物质、有机物和中性洗涤纤维的消化率最高,显著高于其他各饲粮（Ｐ＜０．０５）,其次为饲粮Ｂ和饲粮 Ｃ,饲粮 Ａ最低,显著低于其他各饲粮（Ｐ＜０．０５）,各饲粮的酸性洗涤纤维消化率差异不显著（Ｐ＞０．０５）。粗饲料组合显著影响饲粮摄入总能、能量消化率和能量代谢率（Ｐ＜０．０５）,饲粮 Ｄ甲烷能占摄入总能比显著低于其他 ３种饲粮（Ｐ＜０．０５）。各饲粮的粪氮、尿氮占摄入总氮比差异不显著（Ｐ＞０．０５）,饲粮 Ｄ的氮消化率显著高于饲粮 Ｂ与饲粮 Ｃ（Ｐ＜０．０５）,且饲粮 Ｂ显著高于饲粮 Ａ（Ｐ＜０．０５）;饲粮 Ｂ、饲粮 Ｄ的氮利用率显著高于饲粮 Ａ（Ｐ＜０．０５）。由此可见,玉米青贮 ＋苜蓿草 ＋羊草型饲粮的养分消化率、能量和氮的利用均优于其他各饲粮,羊草与玉米秸秆之间存在正组合效应,两者搭配使用可提高玉米秸秆的消化率,优化能量和氮的利用。