体外瘤胃发酵法评定不同类型饲料的营养价值

本试验旨在利用体外瘤胃发酵法评定不同类型饲料的营养价值。试验1比较了不同粗饲料(麦壳、羊草、稻草、高能饲草、美国苜蓿、国产苜蓿、全株玉米青贮、花生秧青贮、玉米秸青贮和杂交高粱青贮)的体外发酵特性,试验2比较了不同蛋白质饲料(豆粕、棉籽粕、菜籽粕、芝麻粕和棕榈粕)的体外发酵特性,试验3比较了不同饲料组合(稻草组合、苜蓿组合、羊草组合和麦壳组合,各组合精料相同)的体外发酵特性。结果表明:玉米青贮(包括全株玉米青贮和玉米秸青贮)和苜蓿(包括美国苜蓿和国产苜蓿)体外发酵48 h的产气量(GP)、干物质降解率(DMD)和总挥发性脂肪酸(TVFA)浓度均显著高于其他粗饲料(P<0.05);麦壳的GP和DMD则显著低于其他粗饲料(P<0.05)。豆粕体外发酵48 h的GP最高,其发酵速度最快。不同蛋白质饲料的有机物降解率(OMD)和DMD差异较大,以豆粕的OMD与DMD最高,显著高于其他蛋白质饲料(P<0.05);微生物蛋白(MCP)浓度也以豆粕最高,显著高于芝麻粕和棕榈粕(P<0.05)。对于不同饲料组合,中性洗涤纤维与粗蛋白质比值(NDF/CP)越小,其发酵速度越快、降解率越高。相关性分析显示,NDF/CP与DMD呈显著负相关(P<0.05)。结果提示:1)对于粗饲料,玉米青贮和苜蓿类饲料的体外发酵GP较高,发酵速度较快;麦壳的体外发酵GP较低,发酵速度较慢。2)对于蛋白质饲料,豆粕的体外发酵GP、发酵速度和MCP浓度均高于其他蛋白质饲料。3)对于饲料组合,NDF/CP会影响体外发酵特性,NDF/CP越小,其发酵延滞期越短、发酵速度越快、降解率越高。     

西北地区4种优质饲草的肉牛体外瘤胃发酵性能研究

本试验选用黄土高丘陵沟壑区推广应用的玉米、燕麦、苜蓿裹包青贮及苜蓿干草为试验材料,旨在研究其在肉牛体外瘤胃发酵性能及组合效应,为其科学应用提供技术支持。将4种优质饲草按干物质基础组成7种不同比例组合,即C₁(50%玉米青贮+50%燕麦青贮)、C₂(50%玉米青贮+50%苜蓿青贮)、C₃(80%玉米青贮+20%苜蓿干草)、C₄(50%燕麦青贮+50%苜蓿干草)、C₅(70%玉米青贮+10%燕麦青贮+20%苜蓿青贮)、C₆(65%玉米青贮+15%燕麦青贮+25%苜蓿青贮)和C₇(50%玉米青贮+20%燕麦青贮+30%苜蓿青贮)共构成11种发酵底物。结果表明:4种单一饲料在各时间点的产气量(GP)玉米青贮最高,苜蓿青贮最低(P<0.05);7种组合不同时间点产气特点为,C₃的GP最高,C₄最低(P<0.05)。4种单一饲料的快速降解部分产气量(a)和产气速率常数(c)分别为玉米青贮和苜蓿干草最高,与其他单一饲料存在显著差异(P<0.05);7种组合中的a和c均以C₂最高;慢速降解部分产气量(b)和潜在产气量(a+b)均以C₃最高,亦均显著高于其他组合(P<0.05)。体外发酵48 h后,4种单一饲料中玉米青贮的干物质消失率(DMD)显著高于其他3种(P<0.05);培养液的pH介于6.27~6.72,且各组间差异显著(P<0.05);氨态氮(NH₃-N)浓度燕麦青贮最高(P<0.05)。7种组合的DMDC₂显著低于C₅和C₇(P<0.05);pH介于6.40~6.69,其中C₃显著低于其他6种(P<0.05);NH₃-N的浓度C₁与C₂显著高于其他5种(P<0.05)。4种单一粗饲料的总挥发性脂肪酸(TVFA)为玉米青贮显著高于苜蓿青贮和干草(P<0.05);7种组合培养48 h后,培养液的TVFA浓度C₂和C₄显著低于C₅和C₆(P<0.05)。综上,玉米青贮的体外发酵GP、DMD、TVFA及乙酸浓度均最高;苜蓿青贮的体外发酵GP较低,发酵速度慢;不同组合的综合组合效应值(MFAEI)均为正值,由高到低依次为C₄、C₂、C₅、C₁、C₃、C₆、C₇。     

体外产气法评价刺梨果渣对肉羊瘤胃体外发酵参数的影响

研究旨在利用体外产气法评价不同水平刺梨果渣的肉羊瘤胃体外发酵参数,为开发利用刺梨果渣饲料资源奠定基础。以4只成年山羊作为瘤胃液供体羊,体外发酵底物为动物饲养试验中肉羊采食的3组饲粮(对照组：不含刺梨果渣;处理1组：含12%刺梨果渣;处理2组：含24%刺梨果渣),测定产气量、发酵参数、纤维素酶活性。结果显示：处理1组6 h累计产气量(GP_{6 h})显著高于对照组(P<0.05),3组间其余时间点产气量差异不显著(P>0.05)。处理1组总挥发性脂肪酸、乙酸含量具有高于对照组、处理2组的趋势(P=0.08);3组间其余发酵参数[氨态氮(NH₃-N)、干物质降解率(DMD)和有机物降解率(OMD)]无显著差异(P>0.05)。3组间瘤胃纤维素酶(纤维二糖酶、羧甲基纤维素酶、木聚糖酶)活性不受刺梨果渣水平的影响,差异不显著(P>0.05)。由此可见,刺梨果渣对肉羊瘤胃体外发酵没有负面影响,可作为肉羊饲料使用,适量水平(12%)的刺梨果渣可提高产气量,促进瘤胃发酵,但仍需结合生产实际情况考虑其对肉羊生产性能的影响。     

不同水平蔗糖对泌乳奶牛体外产气和瘤胃发酵的影响

试验旨在探究添加不同水平蔗糖对泌乳奶牛体外产气和瘤胃发酵的影响。以泌乳中期奶牛为瘤胃液供体,设置0%、2%、4%、6%、8%共5个蔗糖添加水平,使用微生物发酵微量产气自动记录仪(AGRS-Ⅲ)记录发酵48 h产气量(GP_{48 h})并拟合产气动力学参数、计算体外干物质消失率(IVDMD)和挥发性脂肪酸(VFA)含量;测定体外发酵0.5、1、2、3、6、48 h的发酵液pH、氨态氮(NH₃-N)含量。结果表明：GP_{48 h}、理论最大产气量(A)、达到1/2产气量的产气速率(AGPR)随蔗糖添加水平提高线性增加(P<0.01),蔗糖添加水平对发酵48 h的IVDMD、发酵液pH、VFA和NH₃-N含量无显著影响;但体外发酵1、2h的发酵液pH线性下降(P<0.01);6%、8%组乙酸和丙酸比例低于其余3组(P<0.01)。本试验条件下,较对照组而言,4%蔗糖组在不改变瘤胃发酵模式的同时,提高了体外产气速率和底物降解速率。     

利用体外产气法对不同处理秸秆-薯渣混合料营养价值的评价研究

本试验旨在通过体外产气法评定不同处理水稻秸秆-马铃薯淀粉渣混合料(PSF:秸秆-薯渣混合料、SSF:秸秆-薯渣固态发酵产物、SFS:秸秆-薯渣青贮)的营养价值。混合料通过体外发酵试验,测定不同时间点的累积产气量,以及24 h体外发酵参数和养分降解率,并分析其发酵动力学参数与养分之间的相关性。结果表明:SFS除72 h,其余时间点的累积产气量均显著高于PSF和SSF(P0.05),SFS和SSF理论最大产气量显著高于PSF(P0.05),分别提高67.2%和71.6%,但PSF产气速度、产气延滞期显著高于SSF和SFS(P0.05)。相比PSF,SSF和SFS显著提高体外干物质降解率(IVDMD)、体外中性洗涤纤维降解率(IVNDFD)和体外粗蛋白质降解率(IVCPD)(P0.05),分别提高34.5%和5.1%、41.8%和5.9%、57.8%和50.0%。饲料最大产气量与酸性洗涤纤维(ADF)含量呈显著正相关关系(P0.05),产气速度与ADF呈显著负相关关系(P0.05),产气延滞期与ADF之间呈极显著负相关关系(P0.01),饲料发酵参数与粗蛋白质(CP)、粗灰分(Ash)、中性洗涤纤维(NDF)无相关性(P0.05)。结合产气量与体外降解数据可知,SSF和SFS饲用价值较高,为秸秆-薯渣混合料作为饲料原料合理配制反刍动物日粮提供理论指导。     

植物乳杆菌对玉米秸秆和水稻秸秆体外发酵特性的影响

本试验旨在探讨植物乳杆菌(Lactobacillus plantarum)对玉米秸秆和水稻秸秆奶牛瘤胃体外发酵特性的影响。采用单因子随机区组试验设计,分别以玉米秸秆和水稻秸秆为发酵底物,分析不同添加水平[0(对照)、0.25×107、0.50×107和0.75×107CFU/m L]植物乳杆菌对发酵底物体外发酵产气量(1、2、4、6、12、24、36、48 h)、产气参数、干物质降解率(DMD)、中性洗涤纤维降解率(NDFD)、发酵液挥发性脂肪酸(VFA)、氨态氮(NH3-N)浓度及p H的影响。结果表明:添加植物乳杆菌能显著提高玉米秸秆发酵初期产气速率和产气量(1~24 h)(P0.05),以添加0.75×107CFU/m L效果最为理想;添加植物乳杆菌能显著提高水稻秸秆体外发酵后期(36~48 h)产气量(P0.05),而以添加0.25×107CFU/m L效果最为理想。随着植物乳杆菌添加水平的增加,2种底物体外发酵液NH3-N浓度均呈现显著的线性增加效应(P0.05)。不同植物乳杆菌添加水平对2种底物体外发酵NDFD、DMD、发酵液VFA(乙酸、丙酸、异丁酸、丁酸和戊酸)浓度以及p H均无显著影响(P0.05)。由试验结果推断,添加植物乳杆菌能促进玉米秸秆和水稻秸秆体外发酵及其氮代谢,同时对维持p H的稳定平衡具有积极作用,最佳添加水平分别为0.75×107和0.25×107CFU/m L。     

甜高粱的饲用价值及其绵羊体外瘤胃发酵产气性能研究

本试验旨在研究不同收割时期饲用甜高粱的饲用价值及其绵羊体外瘤胃发酵产气性能,分别对8-11月收割的甜高粱(大奖3180,标记为S₁、S₂、S₃与S₄)的养分含量及相对饲喂价值(RFV)、总可消化养分(TDN)、干物质采食量(DMI)、可消化干物质(DDM)和牧草相对饲用品质(RFQ)进行评价。利用体外模拟发酵产气技术评定不同收割时期的甜高粱在3、6、9、12、24、36和48 h体外产气规律,估算降解率。结果表明,1)不同收割时期的甜高粱的干物质(DM)、粗蛋白(CP)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)、粗脂肪(EE)和粗灰分(Ash)含量差异均显著(P<0.05)。2)不同收割时期的甜高粱的RFV、DMI、RFQ呈现出S₁>S₄>S₃>S₂,差异极显著(P<0.001)。S₁和S₄的TDN和DDM含量差异不显著(P>0.05),但极显著高于S₂和S₃(P<0.001)。3)在培养12 h之前,不同收割时期的甜高粱产气量(GP)差异极显著(P<0.001),且S₃的GP最高;24 h后,S₄的GP显著高于S₂(P<0.05);培养36 h后不同收割时期的甜高粱GP差异不显著(P>0.05)。4)不同时期收割的甜高粱在发酵12、24、48 h的干物质消失率(DMD)均无显著差异(P>0.05)。综上结果,8月对黄土高原丘陵沟壑区甜高粱进行收割时饲用价值最好。     

酿酒酵母和地衣芽孢杆菌对绵羊瘤胃体外发酵的影响

本试验旨在研究添加酿酒酵母和地衣芽孢杆菌对瘤胃体外发酵的影响。在精粗比为50：50的日粮中添加酿酒酵母6×10¹¹ CFU/kg和5种水平的地衣芽孢杆菌[0（C1组）、1×10¹¹（C2组）、2×10¹¹（C3组）、3×10¹¹（C4组）和4×10¹¹CFU/kg（C5组）],并且设置空白对照组（两种菌均不加）（C组）,制成6种发酵底物。测定体外发酵48 h产气参数、CH₄浓度、培养液发酵指标和饲料养分消失率。结果显示：①酿酒酵母和地衣芽孢杆菌共同作用对24、48 h累积产气量、快速发酵部分产气量、慢速发酵部分产气量、潜在产气量和产气速率均有显著影响（P<0.05）,且在地衣芽孢杆菌添加量为2×10¹¹ CFU/kg时产气量和各项产气参数均达到最大值。②酿酒酵母和地衣芽孢杆菌共同作用对pH影响不显著（P>0.05）,但可显著影响氨态氮（NH₃-N）和微生物蛋白（MCP）产量（P<0.05）。当地衣芽孢杆菌添加量为2×10¹¹ CFU/kg时,NH₃-N浓度最小,MCP含量最大。③酿酒酵母和地衣芽孢杆菌共同作用对干物质消失率（DMD）、有机物消失率（OMD）和代谢能（ME）影响显著（P<0.05）,对中性洗涤纤维消失率（NDFD）和酸性洗涤纤维消失率（ADFD）无显著影响（P>0.05）,且DMD、OMD、NDFD和ME在地衣芽孢杆菌添加量为2×10¹¹ CFU/kg时最大,ADFD最小。综上所述,酿酒酵母和地衣芽孢杆菌联用能促进绵羊瘤胃体外发酵,整体来看,当酿酒酵母的添加量为6×10¹¹ CFU/kg和地衣芽孢杆菌添加量为2×10¹¹ CFU/kg时,作用效果最好。     

不同精粗比日粮中添加甘露寡糖对绵羊体外发酵的影响

试验旨在研究不同精粗比日粮中添加甘露寡糖(MOS)对绵羊体外发酵的影响。采用4×6二因子析因试验设计,在4种精粗比日粮(20:80、30:70、40:60及50:50)中分别添加6个水平的MOS(0、0.4%、0.8%、1.2%、1.6%及2.0%),以体外产气法对各底物培养3、6、9、12和24h的产气量、甲烷(CH₄)产量、体外干物质消失率(IVDMD)、体外粗蛋白质消失率(IVCPD)、体外有机物质消失率(IVOMD)进行测定。结果表明:日粮精粗比对体外总产气量(除12、24h)和甲烷(CH₄)产量(除9h)均没有显著影响(P>0.05),日粮精粗比对IVDMD、IVOMD和IVCPD均产生了显著的影响(P<0.05);MOS仅对24h IVCPD产生了显著的影响(P<0.05);日粮精粗比和MOS的交互作用对体外产气量、CH₄产量、IVDMD、IVOMD和IVCPD均没有产生显著的影响(P>0.05)。随日粮中精饲料比例的上升,IVCPD下降而IVDMD和IVOMD在升高;随日粮中MOS比例的升高,IVCPD升高。综上所述,在精粗比为30:70的日粮中添加1.2% MOS效果最好。     

不同季节高寒草甸牧草瘤胃发酵特性和体外消化率分析

本文旨在探讨不同生育时期高寒草甸牧草的牦牛瘤胃体外发酵参数及CH₄产量。通过测定返青期、青草期和枯草期3个生育时期牧草的营养品质、瘤胃发酵参数和CH₄产量。结果表明：青草期牧草总能（Gross energy，GE）、粗蛋白（Crude protein，CP）和粗脂肪（Ether extract，EE）等均显著高于返青期和枯草期（P<0.05）；青草期牧草在各发酵时间点的体外干物质消化率（Dry matter digestibility，DMD）、粗蛋白消化率（Crude protein digestibility，CPD）和有机物质消化率（Organic matter digestibility，OMD）均显著高于返青期和枯草期（P<0.05）；青草期牧草12，24和48 h瘤胃NH₃-N、乙酸、丙酸、异丁酸、丁酸和异戊酸含量显著高于返青期和枯黄期（P<0.05）；不同发酵时间牧草总产气量和CH₄产量变化规律为：返青期>青草期>枯草期。综上所述，青草期草地生物量最高，牧草营养品质和体外消化率最高，CH₄排放最低，瘤胃发酵模式最优。建议选择青草期牧草放牧。     

Nutrient Value Evaluation of Different Type Feeds by in vitro Gas Production Method

The experiment was conducted to evaluate nutrient value of ruminant feeds by in vitro gas production method.The volume of gas production(GP) at 2, 6, 12 and 24 h, in vitro fermentation parameters and nutrient degradation rate of three energy feeds(corn, corn bran and wheat bran) and three roughages(alfalfa meal, alfalfa hay and corn silage) were measured, and gas production kinetic parameters among different feeds and the relationship between fermentation kinetics and nutritent composition were analyzed.The results showed that the GP₂₄, theoretical gas production(A) and B of corn was the highest among energy feeds, but there was no significant differences of B among different energy feeds(P>0.05).The DMD of corn, the NDFD of corn bran and the CPD of wheat bran were the highest;There were no significant differences in GP₂₄ among roughages.The GP₂₄, A, DMD, CPD of alfalfa meal were the highest, while there was no significant differences of B among roughages(P>0.05).Correlation analyses indicated that the theoretical maximum gas production and the accumulative gas production were extremely significant negatively related to CP, NDF, ADF and Ash(P<0.01).Therefore, the experiment revealed that significant differences were observed in in vitro gas producetion kinetic parameters among different feeds, which could supply scientific basis for diet formulation in dairy practice.     

Effect of Compound Enzyme and Compound Enzyme Probiotics Preparation on Degradation Rate of Diet in vitro and Milk Production Performance of Dairy Cows at Different Lactation Stages

The purpose of this experiment was to study the effect of compound enzyme and compound enzyme bacteria preparation on the degradation rate of diet in vitro and milk production performance of dairy cows at different lactation stages.In in vitro experiment,the basic diet (group Ⅰ) and the basic diet added with compound enzyme (group Ⅱ) and compound enzyme probiotics preparation (group Ⅲ) were used as fermentation substrate respectively.After 72 h of culture in vitro,the dry matter degradation rate (DMD) and crude protein degradation rate (CPD) of the diet were measured at different time (6,12,24,36,48 and 72 h).In feeding experiment,24 dairy cows with similar body weight,parity and condition were divided into three groups at early lactation (30 d±5 d),middle lactation (100 d±5 d) and late lactation (250 d±5 d),respectively.The cows in control group (group Ⅰ) were fed with TMR,in compound enzyme group (group Ⅱ) and the compound enzyme probiotics group (group Ⅲ) were fed with the TMR added with 1 kg/t compound enzyme and compound enzyme probiotics respectively.The trial period was 74 days,including 14 days of pre trial period and 60 days of normal trial period.`The results showed that:①In vitro DMD and CPD of the two groups increased with the prolongation of treatment time.At each time point,the values of DMD and CPD in group Ⅲ were higher than those in group Ⅱ,the difference of DMD was significant at 6 and 72 h (P<0.05),CPD was significant at 36 and 72 h (P<0.05),and there was no significant difference at other time points (P>0.05).②In the early stage of lactation,the average daily milk production of groups Ⅱ and Ⅲ increased by 3.68% and 4.10% respectively compared with group Ⅰ,the difference was significant (P<0.05),and the difference between groups Ⅱ and Ⅲ was not significant (P>0.05).In mid-lactation,the average daily milk production of groups Ⅱ and Ⅲ increased by 7.53% and 10.66% respectively compared with group Ⅰ (P<0.05),and the difference between groups Ⅱ and Ⅲ was not significant (P>0.05).In the later stage,the average daily milk production of groups Ⅱ and Ⅲ increased by 7.06% and 5.16% respectively compared with group Ⅰ (P<0.05),and the difference between group Ⅱ and Ⅲ was not significant (P>0.05).In conclusion,both compound enzymes and compound enzyme probiotics preparations could improve the in vitro DMD and CPD of the diet and the milk production of dairy cows in different periods to a certain extent.Among them,the compound enzyme preparation had a better effect on increasing milk production of dairy cows in the late lactation,while the compound enzyme probiotics preparation has a better effect on increasing milk production in mid-lactating dairy cows.     

复合酶与复合酶菌制剂对日粮体外降解率及不同泌乳阶段奶牛产奶性能的影响

本试验旨在研究复合酶及复合酶菌制剂对奶牛日粮体外降解率及不同阶段奶牛产奶性能的影响。在体外试验中,分别以基础日粮（Ⅰ组）及基础日粮中分别添加复合酶制剂（Ⅱ组）、复合酶菌制剂（Ⅲ组）的日粮作为发酵底物,体外培养72 h,测定不同时间点（6、12、24、36、48、72 h）日粮干物质降解率（DMD）和粗蛋白质降解率（CPD）。在饲养试验中,分别选取体重、胎次、体况相近的泌乳前期（30 d±5 d）、泌乳中期（100 d±5 d）和泌乳后期（250 d±5 d）奶牛各24头,平均分成3组,其中对照组（Ⅰ组）奶牛饲喂全混合日粮（TMR）,复合酶制剂组（Ⅱ组）和复合酶菌制剂组（Ⅲ组）奶牛在TMR中分别添加1 kg/t的复合酶制剂和复合酶菌制剂。每期试验持续74 d,其中预试期14 d,正试期60 d,每天记录产奶量。结果显示：①体外试验中,Ⅱ、Ⅲ组的DMD、CPD均随处理时间的延长而增加。在各个时间点,Ⅲ组的DMD、CPD均高于Ⅱ组,其中DMD在6、72 h时差异显著（P<0.05）,CPD在36、72 h时差异显著（P<0.05）,在其他时间点差异均不显著（P>0.05）。②在泌乳前期,Ⅱ、Ⅲ组的平均日产奶量与Ⅰ组相比分别提高了3.68%和4.10%,差异显著（P<0.05）,Ⅱ、Ⅲ组之间差异不显著（P>0.05）;泌乳中期,Ⅱ、Ⅲ组的平均日产奶量与Ⅰ组相比分别提高了7.53%和10.66%,差异显著（P<0.05）,Ⅱ、Ⅲ组之间差异不显著（P>0.05）;泌乳后期,Ⅱ、Ⅲ组的平均日产奶量与Ⅰ组相比分别提高了7.06%和5.16%,差异显著（P<0.05）,Ⅱ组、Ⅲ组之间差异不显著（P>0.05）。综上,复合酶与复合酶菌制剂均能在一定程度上提高日粮体外DMD和CPD以及奶牛在不同时期的产奶量,其中,复合酶制剂对提高泌乳后期奶牛产奶量效果更好,复合酶菌制剂对提高泌乳中期奶牛产奶量效果更好。     

基于主成分分析的精料、构树和全株玉米青贮的组合效应评价

本试验旨在利用主成分分析评价精料、构树和全株玉米青贮以不同比例组合后的组合效应，筛选最佳组合比例。试验设计3个精粗比(40∶60，50∶50，60∶40)，15种日粮组合比例，利用体外模拟瘤胃发酵测定15个组合的瘤胃发酵指标，通过主成分分析法对其进行综合评价。精粗比40∶60时，40∶60∶0和40∶45∶15组的氨态氮(NH₃-N)含量较高；精粗比50∶50时，50∶0∶50，50∶12.5∶37.5和50∶25∶25组的72 h产气量(GP₇₂)较高(P>0.05)，50∶25∶25组的NH₃-N含量最高；精粗比60∶40时，60∶10∶30组的乙酸(AA)、丙酸(PA)和总挥发性脂肪酸(TVFA)浓度显著高于其他各组(P<0.05)。精料∶构树∶全株玉米青贮比例为60∶10∶30，综合主成分值最大。在本试验条件下，日粮中添加构树可以改善肉牛体外瘤胃发酵性能，当精料∶构树∶全株玉米青贮比例为60∶10∶30时，组合效果最佳。     

用体外发酵法评价亚热带几种常用反刍动物饲料的营养价值

试验旨在用体外发酵法评价亚热带多种常用反刍动物饲料的营养价值。选用甘蔗尾、紫色象草、桂闽引象草、构树、玉米秸秆、菠萝皮、鲜豆腐渣、鲜啤酒渣和罗汉果渣9种饲料作为发酵底物,通过瘘管采集成年湘东黑山羊的瘤胃液,利用全自动体外模拟瘤胃发酵设备进行48 h体外发酵。根据总产气量（TGP）、甲烷产量、干物质降解率（DMD）以及挥发性脂肪酸（VFA）浓度等发酵参数进行评价。结果表明：几种料渣中,48 h总产气量、甲烷产量、干物质降解率和VFA浓度由高到低的顺序均为鲜豆腐渣、菠萝皮、鲜啤酒渣、罗汉果渣;几种草料中,玉米秸秆的甲烷产量最高,构树的48 h总产气量、干物质降解率和VFA浓度最高,罗汉果渣的这几项指标均最低。由上述结果可知,从常规营养成分、体外发酵产气和挥发性脂肪酸浓度等方面综合考虑,除罗汉果渣外,其他8种常用饲料均可作为反刍动物的优质饲料加以开发利用。     

Effects of Adding Mannan Oligosaccharides to Diets with Different Concentrate to Forage Ratios on Ruminal Fermentation of Sheep in vitro

The test was aimed at determining the effects of adding MOS to diets with different concentrate to forage ratios on ruminal fermentation of sheep in vitro.The 4×6 two-factor experimental design was chosen.There were 4 diets with different concentrate to forage ratios(20:80, 30:70, 40:60 and 50:50) and added to 6 dosages MOS(0, 0.4%, 0.8%, 1.2%, 1.6% and 2.0%), respectively.The method of gas production in vitro was used to measure the total gas and CH₄ production, IVDMD, IVCPD and IVOMD after cultured for 3, 6, 9, 12 and 24 h.The results showed that the gas(except 12 and 24 h) and CH₄ production(except 9 h) were not impacted by the two factors(P>0.05).The IVDMD, IVCPD and IVOMD were significantly affected by concentrate to forage ratios(P<0.05), while the IVCPD at 24 h was significantly affected by MOS(P<0.05).Meanwhile, all the indexes were not influenced by the interaction of two factors(P>0.05).The IVDMD and IVOMD increased with the rising of concentrate approximately, while the IVCPD decreased with the rising of MOS roughly.The biggest associative effect was gained in 30:70 concentrate to forage diet when adding 1.2% MOS.     

响应面法优化蒸汽爆破小麦秸秆工艺

试验旨在利用Box-Behnken响应面法优化蒸汽爆破预处理小麦秸秆最佳条件，从而解决小麦秸秆营养成分利用率较低的问题。选取蒸汽压强（1.5~2.5 MPa）、水分含量（10%~50%）和维压时间（90~210 s）为自变量，瘤胃体外发酵产气速率为响应值，利用响应面建立回归模型并进行回归方程拟合，预测最佳工艺参数。结果显示：维压时间对瘤胃体外发酵产气速率的影响极显著（P<0.01），蒸汽压强和水分含量对瘤胃体外发酵产气速率无显著影响（P>0.05）。由F值可知：3个自变量对瘤胃体外发酵产气速率的影响大小依次为维压时间、蒸汽压强和水分含量。Box-Behnken响应面法优化蒸汽爆破预处理小麦秸秆的最优工艺参数为蒸汽压强1.77 MPa、水分含量49.91%和维压时间209.98 s。此条件下瘤胃体外发酵产气速率可达0.0794 mL/h。3次平行试验验证的体外发酵产气速率为0.0786 mL/h，与理论预测值误差仅为1.02%。将小麦秸秆在最佳爆破条件下重新爆破并进行体外发酵试验，与未蒸汽爆破的小麦秸秆相比，蒸汽爆破极显著降低了小麦秸秆中中性洗涤纤维（NDF）、酸性洗涤纤维（ADF）和半纤维素的含量（P<0.01），同时极显著提高了体外发酵液中挥发性脂肪酸（VFA）和NH₃-N的含量（P<0.01）。综上，采用响应面法优化蒸汽爆破小麦秸秆的条件合理可行，优化的蒸汽爆破参数可用于提高小麦秸秆营养价值的蒸汽爆破工艺中。     

Effects of Resveratrol on in vitro Fertilization of Sheep Oocytes

The purpose of this study was to investigate the effects of resveratrol (RES) at different concentrations (0,0.5,2.0,5.0 μmol/L) on in vitro fertilization (IVF) and antioxidant capacity of ovine oocytes and the secretion of steroid hormones by cumulus cells.Sheep oocytes were fertilized in vitro after maturated in different concentrations of RES for 24 h,and the in vitro maturation (IVM) medium was collected for detecting the enzyme activity of superoxide dismutase (SOD),glutathione peroxidase (GSH-Px) and the content of monochrome display adapter (MDA).The ELISA method was used to detect the concentration of estradiol (E₂) and progesterone (P₄).The results showed that when compared to the control group,adding 0.5 μmol/L RES to the IVM medium significantly increased the cleavage rate (P<0.05),but had no significant effect on the fertilization rate and blastocyst rate (P>0.05);5.0 μmol/L RES significantly reduced the fertilization rate,cleavage rate and blastocyst rate (P<0.05),which had an inhibitory effect on embryonic development.Adding 0.5 μmol/L RES to IVM and IVC (in vitro culture,IVC) medium significantly increased the fertilization rate,cleavage rate and blastocyst rate (P<0.05).Compared to the control group,the addition of RES to IVM solution had a certain inhibitory effect on the secretion of E₂ by cumulus cells,5.0 μmol/L RES significantly reduced E₂ concentration (P<0.05);0.5 μmol/L RES significantly increased the P₄ secretion of cumulus cells (P<0.05).0.5 and 2.0 μmol/L RES increased the activity of SOD,GSH-Px and other enzymes,but there was no significant difference when compared with the control group (P>0.05),but significantly reduced MDA content (P<0.05),while 5.0 μmol/L RES significantly reduced the activity of antioxidant enzymes and increased the content of MDA (P>0.05).In conclusion,0.5 μmol/L RES simultaneously added to IVM and IVC medium could enhance the antioxidant capacity of oocytes and concentration of P₄,and reduced the content of MDA,thus improved the cleavage rate and blastocyst rate.