用胃管采集瘤胃液测定饲料干物质的体外消化率

本试验用胃管瘤胃瘘管采集瘤胃液,对112个饲样用两级离体法测定干物质消化率,结果两种方法测定的消化率均值分别为72.43±9.11%(52.57%—96.80%)和72.27±9.54%(52.10%—96.80%)。两种方法测定结果无显著差异(P>0.05),并存在如下回归关系:Y=1.6190+0.9754x(RSD=3.50,r=0.9809)。笔者认为可以用胃管代替瘤胃瘘管采集瘤胃液,进行两级离体法饲料干物质消化率测定。     

高山草原绵羊放牧生态及消化代谢系列研究Ⅲ。放牧绵羊食入牧草消化率动态及其限制性因素分析

采用羊粪液代替瘤胃液的牧草干物质二级离体消化率和绵羊食道瘗管方法研究高山草原放牧绵羊采食牧草干物质消化率季节动态,结果表明,在草地牧草生长的7月、8月、10月和1月,绵羊食入牧草(DM)消化率分别为61.00±1.96%,58.84±1.93%,51,40±0.84%和40.58±1.13%;同时应用灰色关联度分析方法对放牧绵羊食入牧草消化率限制因素综合分析认为:湿度、CP、NFE是影响消化率的主要因素。     

不同蛋白和中性洗涤纤维水平对瘤胃发酵、消化和微生物蛋白合成的影响

以3头装有瘤胃瘘管的干奶牛作为瘤胃液供体,用体外培养法研究不同日粮蛋白和中性洗涤纤维(NDF)水平对瘤胃发酵、消化和微生物蛋白合成的影响。采用2×3双因子完全随机设计,粗蛋白水平14%、16%和18%,NDF水平为32%和36%。体外发酵后2、4、6、12、24 h取瘤胃液测定pH、NH3-N浓度和微生物蛋白含量,发酵结束后测定饲料中干物质(DM)、NDF和酸性洗涤纤维(ADF)消化率。结果表明:随着蛋白水平升高,瘤胃发酵pH有增加趋势(P=0.079),显著提高NDF和ADF消化率和细菌蛋白合成量(P<0.05),但不影响DM消化率和原虫蛋白的合成量(P>0.05);日粮中NDF水平显著影响瘤胃pH、NH3-N浓度和ADF消化率(P<0.05),但不影响DM和NDF消化率以及微生物蛋白的合成量(P>0.05)。本试验条件下,日粮中16%CP和32%NDF组可在一定程度上促进瘤胃发酵,提高纤维消化率以及微生物蛋白的合成量。     

用粪液代替瘤胃液测定饲料干物质的体外消化率

用瘤胃液进行两极离体消化测定饲料干物质消化率在国外已经应用,但此法需要通过瘤胃瘘管采集瘤胃液,而瘤胃瘘管的手术及羊的护理都比较费时,并且瘘管对羊的正常生理功能有不良影响,为了克服这些缺点,本试验采用羊粪制备液代替瘤胃液测定了不同饲草饲料的干物质消化率(DMD),并对测定时的最适称样量和粪液加入量进行了筛选。     

不同碳水化合物比例饲粮体外消化率的动态研究

1963年,英国营养学家Tilley和Terry首次提出了反刍家畜两极离体消化试验法。经过不断改进和完善,被认为是间接测定饲草常规体外消化率比较可靠的方法。该方法省时、省力,不需大批试验动物,并可同时进行多种处理的比较;且所测得的结果与体内消化法有高度的相关性,被广泛应用。但是此法要求采集反刍动物瘤胃液,必须有相应的瘤胃瘘管羊,对试验条件和工作量都有较高的要求。而羊粪液来源方便,处理简单,易于操作,对两极离体消化法的推广应用都比较有利。本试验采用羊粪液法测定了不同碳水化合物比例饲粮的体外干物质（DM）和有机物质（OM）的消化率,并探讨了消化率与营养成分之间的互动关系,进而为广泛应用于反刍动物饲粮消化率的评定提供科学依据。     

用食道瘘管测定放牧绵羊日采食牧草干物质量

采用食道瘘管技术与两级离体消化试验及外源指示剂Cr_2O_3测定日排粪量技术3结合的方法,在新疆南山夏秋两季牧场分别进行放牧中国美利奴细毛绵羊牧草干物质采食量的测定。测得夏牧场上18只放牧母羊采食牧草干物质量平均为96.02±7.408克/体重公斤~(0.75)和日排粪干物质量平均为38.72±4.20克/体重公斤~(0.75)。秋牧场上8只放牧母羊采食牧草干物质量平均为75.41±5.799克/体重公斤~(0.75)和日排粪干物质量为38.31±2.73克/体重公斤(0.75)。测得用3只食道瘘管羊采集夏秋牧场上牧草标样的干物质消化率分别为59.65±2.376％与49.02±5.538％,秋季采食牧草干物质量及消化率均显著大于秋季(p<0.001)。两季牧场的日排粪干物质量没有显著性差异(p>0.05)。     

用羊粪液测定牧草干物质的体外消化率

用羊粪液测定牧草干物质的体外消化率郝正里，马海生，高凯，王彦文（甘肃农业大学畜牧系）Ｔｅｒｒｙ和Ｔｉｌｌｅｙ（１９６３）提出的用瘤胃液和酸性胃蛋白酶进行的两级离休消化法，所测结果与体内消化法有高度的相关关系，已广泛应用。为了免去痿管动物，Ｊａｎｅｓ和...     

高山草原绵羊放牧生态及消化代谢研究Ⅳ采食量和消化代谢季节动态

利用放牧绵羊食道瘘管采集牧草样品,全收粪和羊粪液代替瘤胃液的二级离体消化法测得甘肃高山细毛羊成年羯羊在7、8、10和1月采食牧草干物质量依次为:1115.91士158.52、1397.04士97.06、1314.69士145.40和715.55±116.32g/d.同时测定了绵羊有机物、粗蛋白质、消化能、代谢能、钙和磷采食量,并与NRC有关标准进行了比较,指出不同时期本区放牧绵羊CP和ME采食量的盈亏.随着放牧绵羊日采食量的减少,CP存留率和可消化CP利用系数则有大幅度提高.     

高山草原绵羊放牧生态及消化代谢研究 Ⅳ采食量和消化代谢季节动态

利用放牧绵羊食道瘘管采集牧草样品,全收粪和羊粪液代替瘤胃液的二级离体消化法测得甘肃高山细毛羊成年羯羊在7、8、10和1月采食牧草干物质量依次为1115.91士158.52、1397.04士97.06、1314.69士145.40和715.55±116.32g/d.同时测定了绵羊有机物、粗蛋白质、消化能、代谢能、钙和磷采食量,并与NRC有关标准进行了比较,指出不同时期本区放牧绵羊CP和ME采食量的盈亏.随着放牧绵羊日采食量的减少,CP存留率和可消化CP利用系数则有大幅度提高.     

金钱豹消化试验

为探讨金钱豹对含植物性成分的混合日粮的消化情况,采用市售某品牌罐装犬粮(简称罐头组)饲喂7只金钱豹,测定其主要营养成分的表观消化率,同时设牛肉和瘦猪肉组成的纯肉日粮(简称纯肉组)作为对照。结果表明,纯肉组干物质、粗蛋白、脂肪、能量等主要营养成分的表观消化率分别为：(97．37±0．69)％、(98 98±0．32)％、(97．78±0．47)％、(98．30±0 43)％,罐头组干物质、粗蛋白、脂肪、能量等主要营养成分的表观消化率分别为：(74．49±4．18)％、(85．74±1．50)％、(90．45±5．02)％、(94．92±3．27)％。其中干物质和蛋白质的表观消化率组问呈极显著差异(P＜0．01),脂肪的表观消化率组间达显著差异(P＜0．05),而能量的表观消化率组间差异不显著(P＞0．05)。     

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。     

用绵羊小肠液冻干粉评定瘤胃非降解精饲料残渣的有机物于小肠消化率方法的研究

本试验旨在筛选用绵羊小肠液冻干粉评定瘤胃非降解精饲料残渣的有机物于小肠消化率的最佳培养条件。试验包括三部分 :第一个试验研究了小肠液冻干粉用量 ( 0 .2、0 .3、0 .4与 0 .5g)与缓冲液种类(McDougall缓冲液与磷酸盐缓冲液 )对 1 2h瘤胃非降解玉米与豆粕的有机物于小肠消化率的影响 ;第二个试验研究了缓冲液pH值 ( 7.0、7.5与 8.0 )与Ca2 + 浓度 ( 3 4 0、680与 2 0 0 0 μmol/L)对 1 2h瘤胃非降解玉米与豆粕的有机物于小肠消化率的影响 ;第三个试验研究了离体培养时间 ( 3、6、9、1 2、1 5、1 8、2 1与 2 4h)对1 2h瘤胃非降解玉米与豆粕的有机物于小肠消化率的影响。筛选的用绵羊小肠液冻干粉评定瘤胃非降解精饲料残渣的有机物于小肠消化率的适宜条件为 :0 .4 5g小肠液冻干粉 / 0 .56g饲料 ,McDougall缓冲液 ,pH =7.5,Ca2 + =680 μmol/L ,3 9℃ ,瘤胃非降解玉米与豆粕的最佳培养时间不同 ,分别为 1 2与 1 8h     

The estimation of utilizable amino acids (uAA) of feeds for ruminants using an in vitro incubation technique

The in vitro incubation technique of Zhao and Lebzien (2000; Arch. Anim. Nutr. 53, 293-302) was used for the estimation of utilizable amino acids (uAA) (sum of amino acids from undegraded feed protein and microbial protein, when N is not limiting) of feeds for ruminants. The rumen fluid from a cow fed only with hay (Expt. 1) and that from a sheep fed with a mixed ration (Expt. 2) was compared with respect to estimation of uAA. In Expt. 1, 30 feeds and feed mixtures were tested and in Expt. 2, 33 feeds and feed mixtures were tested. A close linear relationship was found between the utilizable crude protein (uCP=undegraded feed protein + microbial protein) (X, g/kg) calculated from in vivo experiments and the uAA (Y, g/kg) estimated from in vitro incubations both in Expt. 1: y= 0.95 x-1.39, r2=0.85, p<0.001,n=30; and in Expt. 2: Y=0.85X-6.67,r2= 0.85,p<0.001,n=33. Statistical analysis indicates that there was a significant regressive relationship between uAA determined with the rumen fluid of a sheep (X, g/kg) and uAA determined with the rumen fluid of a cow (Y, g/kg): Y=1.06X+12.4,r2= 0.80,p<0.001,n=27. The results indicate that the in vitro incubation technique of Zhao and Lebzien (2000) can be used for the estimation of uAA of feeds for ruminants. As a rumen-fistulated cow is more expensive than a rumen-fistulated sheep, it is suggested to use a sheep fed a mixed ration as the donor of rumen fluid for the estimation of uAA of feeds with in vitro incubation. Further experiments should be performed to standardize the method and to test the most valid length of the incubation period.     

The effect of copper and cobalt supplementation on the digestibility of fibrous feed in sheep]

The effects of an addition of copper, cobalt, and copper + cobalt on the in vitro digestibility of hay, treated beech sawdust and cellulose by the rumen fluid of sheep fed a complete food ration, complete food ration with 15% treated beech sawdust and a diet consisting of 80% hay and 20% barley were investigated, respectively. The rumen fluid obtained from animals fed a complete food ration showed the significantly higher digestibility of hay (Tab. I) when Cu (P less than 0.05), Co, or Cu + Co (P less than 0.001) had been added into the rumen. The cellulose digestibility increased only after Co application (P less than 0.05). The microelements supplementation in all three forms had a very significant effect on the digestibility of treated beech sawdust by the rumen fluid of sheep fed a diet with 15% sawdust content, although the initial digestibility by the rumen fluid in the control animals (without microelements) was only 44.9%. A similar trend was also observed in the cellulose digestibility, but after Co application this increase was not significant. The rumen fluid of animals fed hay (80%) and barley (20%) showed the highest digestibility. The digestibility of sawdust reached 60% and the of cellulose 95.9% without microelements supplementation (control). In this case the effect of microelement supplementation on the sawdust digestibility was manifested only in the case of cobalt by the digestibility decrease (P less than 0.001). The cellulose digestibility also decreased after administration of Cu (P less than 0.01) and Co (P less than 0.05). The Cu + Co supplementation did not influence its digestibility.(ABSTRACT TRUNCATED AT 250 WORDS)     

用绵羊小肠液冻干粉测定饲料过瘤胃淀粉小肠消化率方法的研究

本试验旨在以玉米为样本筛选用绵羊小肠液冻干粉测定精饲料瘤胃非降解残渣淀粉小肠消化率的最佳培养条件。分别研究了小肠液冻干粉用量(0.2、0.3、0.4、0.5和0.6g)对16h玉米瘤胃非降解残渣干物质和淀粉小肠消化率的影响;离体培养时间(4、8、12、16、20和24h)对16h玉米瘤胃非降解残渣干物质和淀粉小肠消化率的影响。结果表明,在本试验条件下,绵羊小肠液冻干粉测定玉米瘤胃非降解残渣淀粉小肠消化率的最佳用量为0.45g小肠液冻干粉/0.56g玉米瘤胃非降解残渣,最佳培养时间为12h。利用绵羊小肠液冻干粉测定常用饲料过瘤胃残渣淀粉小肠消化率的方法是可行的。     

In vitro gas production profiles to estimate extent and effective first-order rate of neutral detergent fiber digestion in the rumen

An automatic in vitro gas production technique was evaluated for predicting in vivo fiber (NDF) digestibility and effective first-order digestion rate of potentially digestible NDF (pdNDF) of 15 grass silages. Observed in vivo NDF digestibility of the silages harvested at different stages of maturity during 3 yr was determined by the total fecal collection in sheep fed at the maintenance level of intake. Isolated grass silage NDF was incubated for 72 h in the presence of rumen fluid and buffer to determine the pdNDF digestion kinetics based on cumulative gas production profiles. The digestion kinetic parameters were estimated by a 2-pool Gompertz function. The estimated parameter values were then used in a 2-compartment mechanistic rumen model to predict the in vivo digestibility of pdNDF. A total compartmental mean residence time of 50 h was used in the model, and a further assumption of the distribution of the residence time between the rumen nonescapable and escapable pools in a ratio of 0.4:0.6 was made. To make a distinction between potentially digestible and indigestible NDF, the potential extent of NDF digestion was determined by a 12-d ruminal in situ incubation. The model-predicted in vivo NDF digestibility accurately and precisely (root mean square error = 0.013 units, R(2) = 0.99). Effective first-order digestion rate was estimated from the predicted pdNDF digestibility, and the values were compared with those calculated from the in vivo pdNDF digestibility using the same passage kinetic parameters. The predicted effective first-order digestion rate was strongly correlated with digestion rate estimates derived from in vivo data (root mean square error = 0.006/h, R(2) = 0.86). It can be concluded that a simple first-order digestion rate can be estimated from a complicated gas production kinetic model including 6 parameters. This rate constant can be used in continuous steady-state dynamic mechanistic rumen models predicting the nutrient supply to the host animal.     

不同颗粒日粮对滩羊育肥羊生长性能、养分表观消化率及血清生化指标的影响

旨在探究不同颗粒日粮对育肥羊生长性能、养分表观消化率及血清生化指标的影响.选取体重相近、(70±10)日龄的滩羊羯羔羊60只,随机分为4组:对照组(n=15)、试验Ⅰ组(n=15)、试验Ⅱ组(n=15)、试验Ⅲ组(n=15).对照组饲喂自配全混合日粮(40％自配精饲料+60％自配粗饲料),试验Ⅰ组饲喂50％自配全混合日...     

Effect of plant oils and aspartate on rumen fermentation in vitro

The effect of plant oils and aspartate (ASP) on rumen fermentation in vitro. The objective of this study was to determine the effect of plant oils (rapeseed - RO, sunflower - SO; linseed - LO; 10% wt/wt) and 8 mmol sodium aspartate on rumen fermentation of a diet (250 mg) consisting of hay, barley and sugar beet molasses (60 : 30 : 10). Rumen fluid was collected from two Slovak Merino sheep fed the same diet twice daily. Mixed ruminal micro-organisms were incubated in fermentation fluid (40 ml) containing rumen fluid and McDougall's buffer (1 : 4). Incubations were carried out in batch cultures for 72 h at 39 degrees C two times in a 3-week intervals. When compared to the control, all supplemented diets (RO, SO, LO, ASP) significantly increased the pH, the mol% of propionate (LO + 8.7%; SO + 10.12%; RO + 8.65%; ASP + 5.86%) and the acetate : propionate ratio and numerically decreased methane production (SO -32.8%; LO, RO -30.08%; ASP -21.56%). Lactate production was also significantly decreased. Addition of plant oils to aspartate-treated incubations partly inhibited the decrease of n-butyrate, lactate and the increase of pH and in vitro dry matter digestibility (IVDMD) caused by ASP treatment. The effect of combined additives (RO + ASP, SO + ASP, LO + ASP) on methane production SO + ASP (-19.23%) and mol% propionate SO + ASP (+2.66%), LO + ASP (+4.28%) was less effective. All combined additives caused a significant decrease in digestibility of the given feeds. No effect of plant oils and ASP could be observed on the parameters of rumen fermentation (mainly methane and propionate).     

酒糟和醋糟营养成分差异及其瘤胃降解特性分析

本试验旨在评价酒糟、醋糟等非常规饲料资源的饲用价值，为酒糟醋糟资源应用于肉牛养殖提供数据参考。试验选用山西不同地区酒糟、醋糟试样5个，试样编号分别为白酒糟、啤酒糟、醋糟1、醋糟2、醋糟3，发酵原料分别为白酒糟（高粱）、啤酒糟（大麦+大米）、醋糟1（高粱+大麦）、醋糟2（大麦+玉米）、醋糟3（高粱+玉米）。通过实验室常规方法测定样品常规营养成分以及利用体外产气法和尼龙袋法评价其饲用价值，同时建立体外法与尼龙袋法测定干物质降解率的回归方程。结果表明：5个样品的干物质（DM）含量为23.25% ~ 42.96%，粗蛋白质（CP）含量分别为啤酒糟（31.84%）>白酒糟（14.58%）>醋糟3（14.40%）>醋糟1（12.21%）>醋糟2（8.46%）。醋糟1的中性洗涤纤维（NDF）、酸性洗涤纤维（ADF）含量均为最高，其次为醋糟2、醋糟3，白酒糟NDF含量最低。啤酒糟的72 h产气量（GP72）显著高于白酒糟（P < 0.05）。体外产气法和尼龙袋法测定的酒糟72 h干物质降解率（IVDMD72、DMD72）显著高于醋糟（P < 0.05）。5个试样的IVDMD72与DMD成正相关，随着降解时间增加其相关性逐渐增加。综上，酒糟的CP含量较高（14.58% ~ 31.84%），醋糟NDF、ADF含量相对较高（59.59% ~ 64.91%，38.78% ~ 54.78%）。结合GP、IVDMD及DMD结果，酒糟消化性能优于醋糟。以IVDMD建立估算DMD的回归公式为DMD72=-19.215+1.645IVDMD72（R2=0.912，P < 0.05）|以IVDMD建立估算DM有效降解率（ED）的回归公式为ED=-12.448+1.045IVDMD72（R2=0.929，P < 0.01）。 [关键词] 醋糟|酒糟|体外产气法|尼龙袋法     

不同加工方式针茅草对绵羊干物质采食、消化及瘤胃内环境的影响

本试验旨在研究针茅草的不同加工方式对绵羊采食、消化及瘤胃内环境的影响。选用体重[(45±2)kg]、年龄(1.5~2.0岁)相近安装有永久性瘤胃瘘管的乌珠穆沁羯羊48只,随机分为4组,每组12只,分析干草、草颗粒、草块、草粉4种加工方式的针茅草对绵羊干物质采食量、表观消化率及瘤胃液pH及总氮、氨氮、总可利用氮、挥发性脂肪酸浓度的影响。预试期10 d,正试期7 d。结果表明:1)针茅草颗粒的干物质采食量及表观消化率显著高于其他组(P0.05)。2)与其他各组相比,针茅草颗粒组的绵羊食后1 h瘤胃液pH显著降低(P0.05),总氮、氨氮和总可利用氮浓度较高。3)草颗粒组的瘤胃液总挥发性脂肪酸浓度显著高于干草和草粉组(P0.05)。由此可见,针茅草颗粒的干物质采食量、表观消化率以及在绵羊瘤胃内的发酵指标均较优,是饲喂绵羊的最佳利用形态。