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1.
麻叶荨麻与玉米粉混贮对青贮品质的影响 总被引：1，自引：0，他引：1
为解析添加玉米粉对麻叶荨麻青贮发酵品质和养分保存效果的影响,将麻叶荨麻与玉米粉5∶1混合调制青贮饲料,将其DM含量提高到310 g/kg,以麻叶荨麻单独青贮作为对照。每个处理18个重复,室温袋贮60 d后开封取样,测定青贮发酵品质和营养成分及消化率,并分别在贮藏后第0,3,5,15,20和60天调查pH、有机酸、氨态氮的动态变化。结果表明,与玉米粉混合青贮通过快速降低pH和提高乳酸含量而明显加快了麻叶荨麻的发酵进程,发酵前15 d,混贮组pH下降速率和乳酸累积速率较单贮组快;混贮组显著降低了(P<0.05)pH、氨态氮、乙酸、丁酸及NDF和ADF含量,显著提高了(P<0.05)乳酸、水溶性碳水化合物(WSC)含量、费氏评分及干物质与纤维组分的体外消化率;脂肪含量在两个处理之间无显著差异。以上结果表明,麻叶荨麻与玉米粉以5∶1混合青贮能够成功保存麻叶荨麻的高品质营养特性,从而生产高品质青贮饲料,同时还能改善家畜对它的利用效率。 相似文献
2.
为了探讨具有优良抑菌活性的乳酸菌对全株玉米青贮过程不同时期营养品质的影响,进一步验证并筛选出可提高玉米秸秆青贮品质的乳酸菌接种剂,将实验室前期从甘肃各地玉米秸秆青贮饲料中分离筛选获得的5株产酸快、多,且具有抑菌活性的优良乳酸菌分别添加到全株玉米秸秆中进行青贮,共设置6个试验组,分别在青贮第3、7、15、30天测定产物的干物质(DM)、粗蛋白(CP)、可溶性碳水化合物(WSC)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)和氨态氮(NH3-N)含量及第30 天乳酸(LA)、乙酸(AA)、丙酸(PA)和丁酸(BA)含量。结果显示,发酵30 d后,5个处理组的DM、CP、ADF和LA含量显著高于对照组(P<0.05),NH3-N和WSC含量显著低于对照组(P<0.05),B3-1组NDF显著高于对照组(P<0.05),但与其他处理组差异不显著(P>0.05),B3-1和B5-2组AA含量显著高于对照组(P<0.05),但与其他处理组差异不显著(P>0.05);各组DM、CP、WSC含量均随发酵时间延长而降低,而ADF、NDF和NH3-N含量均随发酵时间的延长而升高;B3-1组在玉米秸秆全株青贮发酵各期的发酵品质和营养品质最优。以上结果表明5株乳酸菌均能显著改善青贮饲料发酵品质,其中植物乳杆菌B3-1的效果最好。 相似文献
3.
添加剂和混合比例对裸燕麦和紫花苜蓿混贮品质的影响 总被引：1，自引：0，他引：1
探讨添加剂和不同混合比例对裸燕麦和紫花苜蓿混贮饲料品质的影响,为开展牧草混播及调制高质量的混合青贮饲料提供参考。以裸燕麦和紫花苜蓿为原料,按质量比1∶1、2∶1和1∶2进行混合青贮,并分别加入0.4% 甲酸(formic acid,FA)或2%蔗糖(sucrose,S),青贮60 d后测定混合青贮饲料的发酵品质和营养物质含量。结果显示,裸燕麦与苜蓿混合比例为2∶1时青贮饲料的感官评价上均优于其余2种混合比例,添加0.4%甲酸或者2%蔗糖,感官评定为优并显著高于对照组(P<0.05)。混合青贮饲料的发酵品质随裸燕麦比例增加而不同程度提高。其中,pH值随裸燕麦比例增加而逐渐降低;在裸燕麦与苜蓿混合比例在2∶1时,添加2%蔗糖组乳酸(lactic acid,LA)含量显著高于对照及0.4%甲酸处理组(P<0.05),且与另外2种混合比例的处理组相比差异均显著(P<0.05);此混合比例下添加0.4%甲酸处理组pH值和氨态氮/总氮(AN/TN)较低,乙酸(acetic acid,AA)和总挥发性脂肪酸(total VFA,TVFAs)含量最低,乳酸含量及乳酸/乙酸(LA/AA)较高,丙酸(propionic acid,PA)和丁酸(butyrate acid,BA)含量极低未检出,V-Score评分最高,总体发酵品质最佳。随苜蓿比例增加,混贮饲料CP含量提高,纤维组分(NDF、ADF和HC)含量降低,青贮饲料养分更加均衡,但添加剂对青贮饲料营养成分影响不大。裸燕麦与紫花苜蓿混合青贮可形成养分互补,提高营养价值;加入适量甲酸或蔗糖有助于抑制不良发酵,提高发酵品质。 相似文献
4.
To evaluate the current practice of corn silage management in China, samples of bunker‐made silage were collected from 14 farms within a 500‐km radius of Beijing for the analysis of fermentation products and bacterial communities. Mean values for dry matter (DM) content were as low as 250 g/kg in both corn stover (St) and whole crop corn (Wc) silages, and pH values averaged 4.48 and 3.73, respectively. Only three of the 14 silages exhibited a lactic‐to‐acetic acid ratio > 1.0, indicating that the presence of acetic acid was predominant in fermentation. Although 1,2‐propanediol content was marginal in most cases (< 5.0 g/kg dry matter (DM)), two Wc silages had 1,2‐propanediol levels > 25 g/kg DM. In contrast, 3 St silages had large amounts (> 10 g/kg DM) of butyric acid, and two of the three butyrate silages also had high concentrations of 1‐propanol. Denaturing gradient gel electrophoresis analysis demonstrated that the bacterial community appeared similar in 10 out of the 14 silage samples. Bands indicating Lactobacillus buchneri, L. acetotolerans and Acetobacter pasteurianus were found in both the St and Wc silages, accounting for the high acetic acid content found across silage samples. 相似文献
5.
Six wethers were used in a replicated 3 x 3 Latin square to study the fermentation quality and nutritive value of total mixed ration (TMR) silages that included wet coffee grounds (WCG). The TMR were prepared using a commercial compound feed, timothy hay, alfalfa hay, dried beet pulp, and a vitamin-mineral supplement in a ratio of 36.5:30:20:12:1.5, respectively, on a DM basis, with timothy hay and alfalfa hay being replaced by WCG at 0, 10, or 20%. All TMR silages, irrespective of WCG addition, were well preserved, with a low pH and ammonia-N content and a high lactic acid content. Intakes by wethers of TMR silages containing 0 and 10% WCG were 96.6 and 94.8 g/kg of BW(0.75), and did not differ (P > 0.05). Intake of TMR silage containing 20% WCG was 76.8 g/kg of BW(0.75), which was equal to 80% of that of the TMR silage with no WCG (quadratic: P < 0.01). Increasing concentrations of WCG in the rations decreased the digestibility of DM, CP, ADF, NDF, and energy, and increased that of ether extract (P < 0.05). The TDN and DE contents of the TMR silages with 0 and 10% WCG were similar, but the TMR silage with 20% WCG was lower (P < 0.05). With progressive increases in WCG concentrations, N intake did not differ, but fecal and urinary N increased linearly (P < 0.001), and retained N decreased linearly (P < 0.001). This study demonstrated that the proportion of WCG to be incorporated into TMR silages should not exceed 10% of the DM. 相似文献
6.
Grass was field-dried to 3 different dry matter (DM) levels (200, 430 and 540 g/kg) and inoculated with 10(6)-10(7) cfu/g of a Listeria monocytogenes strain sharing a phagovar occasionally involved in foodborne outbreaks of listeriosis. Formic acid (3 ml/kg) or lactic acid bacteria (8 x 10(5)/g) with cellulolytic enzymes were applied only to forages with low and intermediate DM levels. Forages were ensiled in laboratory silos (1700 ml) and were stored at 25 degrees C for 30 or 90 days. After 90 days of storage, L. monocytogenes could not be detected in any silo, except one with the high dry matter grass without additive. After 30 days of storage, between 10(2) and 10(6) cfu L. monocytogenes/g silage were isolated from the untreated silages. Increasing the DM content from 200 to 540 g/kg did not reduce listeria counts possibly because of the lower production of fermentation acids (higher pH). In silages treated with additives, counts of L. monocytogenes were always lower than in silages without additive. In wet silages (DM 200 g/kg) both additives were effective, but in the wilted silages (DM 430 g/kg) only the bacterial additive reduced listeria counts below detection level. Listeria counts were highly correlated to silage pH (r = 0.92), the concentration of lactic acid (r = -0.80) and the pooled amount of undissociated acids (r = -0.83). 相似文献
7.
本试验旨在研究生物及化学添加剂对不同时期刈割的苜蓿青贮品质的影响。试验采用现蕾期和初花期刈割的中苜一号苜蓿(70%水分含量)为原料,分别设置添加:1)空白组;2)乳酸菌+纤维素酶(105cfu/g+50 mg/kg);3)乳酸菌+纤维素酶(105cfu/g+100 mg/kg);4)甲酸+丙酸(6 mL/kg)4个处理组,使用0.5 L塑料桶调制罐装青贮,并于发酵30 d后开罐取样分析。结果表明,与现蕾期相比,初花期苜蓿青贮饲料的乳酸(LA)产量较高,丁酸(BA)和氨态氮(NH3-N)生成量较低(P<0.01),pH值也较低(P<0.05),同时非蛋白氮(PA)和结合蛋白质(PC)含量也显著低于现蕾期(P<0.01)。3个添加剂处理组均显著地提高了青贮发酵的品质,降低pH值(P<0.01)和氨态氮生成量(P<0.01)。其中,乳酸菌+纤维素酶显著地提高了乳酸含量及乳酸/乙酸(LA/AA)(P<0.01),甲酸+丙酸则显著抑制了丁酸的产生(P<0.01)。同时,3组添加剂均显著地提高了青贮饲料中可溶性碳水化合物(WSC)和粗蛋白(CP)的含量,并降低了中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)的含量(P<0.01)。就蛋白组分而言,乳酸菌+纤维素酶(105 cfu/g+100 mg/kg)和甲酸+丙酸处理组显著地降低了青贮饲料中非蛋白氮和结合蛋白质的含量(P<0.01),提高了真蛋白(PB)的含量(P<0.01)。综合而言,甲酸+丙酸处理组苜蓿青贮料的品质最佳,乳酸菌+纤维素酶(105 cfu/g+100 mg/kg)次之。 相似文献
8.
Effect of inoculants on whole-crop barley silage fermentation and dry matter disappearance in situ 总被引：1，自引：0，他引：1
Whole-crop barley harvested at the mid-dough stage was ensiled in 3-L laboratory silos either directly (at 30.7% DM) or after wilting (37.8% DM), and with or without application of Inoculant A, B, or D. Each inoculant contained multiple strains of Lactobacillus plantarum and Enterococcus faecium. Two silos per treatment were opened on d 1, 3, 7, 15, and 47 for silage analysis. Wilted silages had higher (P < 0.05) pH than unwilted silages, and Inoculant B (unwilted crop) and Inoculants A, B, and D (wilted crop) decreased (P < 0.05) silage pH compared to the controls. Reducing sugars concentration was 36% lower (P < 0.05), on average, in the wilted than in the unwilted silages. Silages prepared with Inoculants B or D had lower (P < 0.05) concentrations of reducing sugars than the control. Wilting of the barley crop further increased the difference between inoculated and control silages (wilting x inoculation P < 0.05). Neither wilting nor silage inoculants affected concentrations of nonprotein N, ammonia N, or free amino acid N in silage. Wilting did not affect the concentration of lactic acid bacteria (LAB) in the silages. Across DM levels, inoculant-treated silages had larger (P < 0.01) populations of LAB than did the uninoculated controls (7.1 x 10(9) vs 2.3 x 10(9) cfu/g silage DM). Wilting resulted in lesser (P < 0.05) silage lactic acid concentration than the directly ensiled crop. At both DM levels, lactic acid concentration was higher (P < 0.001) in inoculated silages than in controls. The in situ soluble and potentially degradable fractions of silage DM were not affected by wilting or inoculant treatment. The rate of degradation of the potentially degradable silage DM was 35% lower (P < 0.05) in wilted than in unwilted silage. As a result, the calculated effective degradability of silage DM was lower (P < 0.001) in wilted than in unwilted silage. Inoculants did not influence the rate of degradation or effective degradability of silage DM in the rumen. Whole-crop barley ensiled at approximately 30% DM (without wilting) contained higher concentrations of soluble sugars and lactic acid and had higher ruminal degradability of DM than wilted silage (38% DM). Although inoculants did not improve DM degradability of barley silage, lower terminal pH and increased concentrations of lactic acid may improve aerobic stability upon feed-out. 相似文献
9.
添加乳酸菌和菠萝皮对柱花草青贮品质的影响 总被引：1，自引：0，他引：1
柱花草是热带、亚热带的优质豆科牧草,蛋白含量高、营养品质好,为促进柱花草的加工利用,本试验研究了添加不同乳酸菌和菠萝皮对其青贮发酵品质和有氧稳定性的影响。青贮处理为CK(对照)、LQ(青贮宝)、LF(发酵乳杆菌)、LP(植物乳杆菌)、LS(鼠李糖乳杆菌)、B(20%菠萝皮)、BLQ(B+LQ)、BLF(B+LF)、BLP(B+LP)、BLS(B+LS)。添加处理后青贮60 d进行分析。结果表明,柱花草含有较少的可溶性碳水化合物和乳酸菌,自然青贮其pH超过5.0,发酵品质差;所有添加物都显著降低pH、增加乳酸含量(P＜0.05),明显改善了柱花草青贮料的发酵品质。单独添加菠萝皮的丁酸和NH3-N含量显著高于所有单独添加乳酸菌(P＜0.05),pH与LP以外的其他3种乳酸菌差异不显著(P＞0.05)。除LP的乙酸含量较高,丁酸含量较低外,4种乳酸菌对其他各个发酵指标的影响没有显著差异(P＞0.05)。本试验所用4种乳酸菌与菠萝皮混合添加,都进一步改善了柱花草青贮料的发酵品质,特别是BLP的青贮效果最佳,其pH值、乙酸和NH3-N含量低,乳酸含量及乳酸与乙酸比高。青贮袋开封后,包括对照在内的所有青贮料的有氧稳定性均较佳。 相似文献
10.
The objectives of this study were to determine the effect of a cellulase (from Trichoderma longibrachiatum) alone or combined with a bacterial inoculant (Lactobacillus plantarum and Pediococcus cerevisiae) or formic acid on composition, intake, and digestibility of orchardgrass (Dactylis glomerata L.) and alfalfa (Medicago sativa L.) silages. Orchardgrass and alfalfa were harvested at the early heading stage and at the early bloom stage of maturity and wilted to approximately 22 and 32% DM, respectively. Forages were then ensiled in 100-L sealed barrels for at least 60 d before they were fed to lambs. Silage treated with cellulase had lower (P < .001) pH and lower (P < .001) acetic acid and NH3 N concentrations than untreated silage of both plant species and a higher (P = .004) lactic acid concentration than the control treatment of alfalfa silage. Fermentation characteristics of cellulase-treated silages, especially of alfalfa, were further enhanced by use of inoculant. Formic acid addition increased (P < .001), reducing sugar concentration of cellulase-treated orchardgrass and alfalfa silage by 90 and 154%, respectively, and decreased (P < .001) NH3 N concentration of cellulase-treated alfalfa silage by 19%. Averaged across plant species, cellulase, combined with inoculant or formic acid, resulted in 8 and 13% greater (P = .03) DMI, respectively, than the control silage. Extensive enzymatic cell-wall degradation during ensiling decreased (P = .003) NDF intake of cellulase-treated orchardgrass silage by 25% and decreased (P = .001) cellulose intake by 23%, when averaged across plant species. Addition of formic acid increased (P = .003) NDF intake of cellulase-treated orchardgrass silage by 19%. Averaged across species, cellulase application decreased (P < .05) silage NDF digestibility by 18%. Greater sugar and lower acetic acid, NH3 N, and NDF concentrations resulted in greater DMI of cellulase-treated silage than of control silage, when cellulase was combined with formic acid or inoculant. 相似文献
11.
试验旨在探讨不同添加剂对青贮稻草品质和有氧稳定性的影响。稻草青贮时,分别添加乳酸菌(L)、乳酸菌+糖蜜(LM)、乳酸菌+纤维素酶(LC)和乳酸菌+糖蜜+纤维素酶(LMC),乳酸菌、纤维素酶和糖蜜剂量分别为5×105 cfu/g、0.6 IU/g、20 mg/g,贮存90 d后开包检测。综合评定青贮稻草的青贮质量,测定常规营养成分,浸提液的pH值、氨态氮和有机酸的含量并测定稻草的有氧稳定性。试验结果:L组、LM组、LC组和LMC组的总综合评分显著高于对照组(P<0.05)。LC、LMC组的酸性洗涤纤维含量显著低于对照组(P<0.05),提高了剩余可溶性碳水化合物的含量。与对照组相比,各处理组均提高了乳酸的含量;LC和LMC组显著提高了乳酸的含量(P<0.05)。对照组的总有机酸含量显著低于LC和LMC组(P<0.05),但是和L、LM组差异不显著(P>0.05)。各组的有氧稳定性和有氧损失均无显著差异(P>0.05)。结果表明:添加乳酸菌,提高了乳酸的含量和综合评分;在乳酸菌的基础上,添加糖蜜或是与纤维素酶的组合,有利于提升发酵品质。 相似文献
12.
为筛选适宜在广州种植的青贮玉米品种,采用随机区组设计种植和袋装青贮的方法,研究了10个玉米品种(京科青贮301、农大108、赣单2、大丰3、宜黄单4、雅玉8、先玉335、郑单958、雅玉26、华玉8)的种植和青贮潜力。结果表明,1)品种间全株干物质产量(P<0.05)和消化率(P<0.01)差异显著,参试品种均超过对照品种华玉8,其中雅玉8的干物质产量最大,达14.30 t/hm2;京科青贮301干物质消化率最高,达78.15%。品种间的相对饲用价值呈现显著差异(P<0.05),京科青贮301的相对饲用价值为123.52,比对照高17.90%(P<0.05),郑单958、赣单2、先玉335、雅玉8、农大108不同程度地高于对照。2)品种间的干物质、粗灰分和无氮浸出物含量差异显著(P<0.05),各品种干物质含量比对照均有不同程度的提高,雅玉26、大丰3、雅玉8干物质含量均达到40%;雅玉26、大丰3、农大108和雅玉8的无氮浸出物含量较高,分别达到65.31% DM、63.94% DM、63.38% DM和62.17% DM。品种间的粗蛋白、粗脂肪和粗纤维含量均无显著差异(P>0.05)。3)玉米品种间植株附着的乳酸菌和霉菌差异显著(P<0.05),郑单958的乳酸菌数达106 cfu/g FM,高于其他品种。4)各玉米品种青贮后的pH值、乳酸和丙酸含量差异显著(P<0.05),对照华玉8的pH值最低为3.63,雅玉8的pH值最高,达4.22;对照华玉8的乳酸含量最高,达9.16% DM。丁酸含量差异不显著(P>0.05),但雅玉8和郑单958没有检测到。各品种青贮的NH3-N/TN含量差异极显著(P<0.01),雅玉8、郑单958和大丰3分别为8.81%、10.04%和10.61%,至少比对照低13.39%。综合各品种全株干物质产量、营养价值和青贮效果,雅玉8在广州地区种植作青贮饲料利用更有潜力。 相似文献
13.
为提高紫花苜蓿青贮饲料的发酵品质,抑制不饱和脂肪酸的损失,以无添加剂为对照,研究了添加剂：苯甲酸钠、酪蛋白酸钠、十六烷酸、糖蜜和丙酸,对紫花苜蓿青贮饲料发酵品质和脂肪酸的影响。青贮65 d后开窖,检测发酵品质指标和各种脂肪酸的含量。结果表明：对照组的pH低于4.50,乳酸含量达到54.25 g·kg-1 DM,丁酸含量低于5.00 g·kg-1 DM,弗氏评分为64.33,具有良好的发酵品质。与青贮前相比,青贮后苜蓿青贮饲料中的亚油酸（C18：2n6）和亚麻酸（C18：3n3）的含量显著增加（P<0.05）。青贮后,与对照组相比,十六烷酸和酪蛋白酸钠添加组分别不显著（P>0.05）和显著地（P<0.05）降低了乳酸含量;酪蛋白酸钠添加组增加了丁酸含量（P<0.05）;二者的弗氏评分低于50.00,降低了发酵品质。与此相反,苯甲酸钠、丙酸和糖蜜添加组不同程度地增加了乳酸含量,降低了pH,减少了氨态氮和酸性洗涤纤维的含量,弗氏评分分别为70.33、74.33和67.67,进一步提高了青贮发酵品质。与对照相比,苯甲酸钠和丙酸添加组不同程度地增加了C18：2n6或C18：3n3的含量,而糖蜜添加组降低了C18：2n6和C18：3n3的含量（P<0.05）。综上所述,丙酸和苯甲酸钠适宜于作为青贮添加剂生产优质紫花苜蓿青贮饲料。 相似文献
14.
Effect of hybrid, maturity, and mechanical processing of corn silage on intake and digestibility by beef cattle 总被引：7，自引：0，他引：7
Andrae JG Hunt CW Pritchard GT Kennington LR Harrison JH Kezar W Mahanna W 《Journal of animal science》2001,79(9):2268-2275
A study involving a 2 x 2 x 2 factorial arrangement of treatments was conducted to evaluate effects of hybrid (Pioneer 3335 and 3489), maturity (half milkline and blacklayer), and mechanical processing (field chopper with and without on-board rollers engaged) on intake and digestibility of corn silage. Forty Angus steers (322 +/- 5.2 kg BW) were assigned to the eight silage treatments (five steers per treatment) and individually fed using electronic gates. Diets consisted of 60% corn silage and 40% chopped alfalfa hay (DM basis). Following a 5-d adaptation period, intake was measured for 7 d and subsequently fecal samples were collected for 5 d. Chromic oxide (5 g/d) was fed beginning 7 d before fecal sample collection and digestibility was determined by the ratio of Cr in the feed and feces. Steers were reallocated to treatments and these procedures were repeated, providing 10 observations per treatment. In addition, all silages were ruminally incubated in six mature cows for 0, 8, 16, 24, 48, and 96 h to determine extent and rate of DM, starch, NDF, and ADF disappearance. Processing increased DMI of hybrid 3489 but did not affect DMI of hybrid 3335 (hybrid x processing; P < 0.06). Total tract digestibility of DM, starch, NDF, and ADF decreased (P < 0.01) as plant maturity increased. Maturity tended to decrease starch digestibility more for hybrid 3489 than for hybrid 3335 (hybrid x maturity; P < 0.10). Processing increased (P < 0.01) starch digestibility but decreased (P < 0.01) NDF and ADF digestibility, resulting in no processing effect on DM digestibility. There was a numerical trend for processing to increase starch digestibility more for latethan for early-maturity corn silage (maturity x processing; P = 0.11). Processing increased in situ rates of DM and starch disappearance and maturity decreased in situ disappearance rates of starch and fiber. These data indicate that hybrid, maturity, and processing all affect corn silage digestibility. Mechanical processing of corn silage increased starch digestibility, which may have been associated with the observed decreased fiber digestibility. 相似文献
15.
H F Tyrrell D J Thomson D R Waldo H K Goering G L Haaland 《Journal of animal science》1992,70(10):3163-3177
First-growth orchardgrass and alfalfa were harvested at two stages of maturity, treated with formic acid plus formaldehyde, and ensiled as direct-cut silage during 1978 and 1979. The 1978 silages were fed to eight yearling Holstein heifers (average BW 273 kg), and the 1979 silages were fed to eight yearling Holstein steers (average BW 264 kg) in replicated 4 x 4 Latin square experiments to measure total energy and N balance using the Beltsville open-circuit respiration calorimeters. Silage was offered daily at 70 g of DM/kg.75 BW, a rate that was essentially ad libitum for late-maturity orchardgrass, but restricted for the other three silages within each experiment. Cattle fed alfalfa used ME for growth with greater efficiency (55%) than did cattle fed orchardgrass (40%). Cattle fed orchardgrass achieved the same tissue N retention at a lower total N intake than did cattle fed alfalfa. Differences in tissue N retention were accounted for by differences in N intake insoluble in autoclaved ruminal fluid, but soluble in acid detergent, a fraction termed available N. At equal intake of ME and available N, cattle fed alfalfa gained more tissue energy than those fed orchardgrass and gained tissue protein similarly to cattle fed orchardgrass. Fractions composing digestible OM were different between forage types but similar within forage type between maturities at harvest. More efficient use of ME for growth by animals fed alfalfa compared with orchardgrass may be related to differences in digestible OM composition, load of digestive tract content, and composition of absorbed nutrients. 相似文献
16.
Two experiments were conducted using laboratory mini-silos to study the effect of ensiling and silage additives on fatty acid (FA) composition, including minor or unusual FA, of ryegrass and corn silages. Ryegrass was ensiled for 12 wk with no additives, with the addition of a bacterial inoculant or formic acid. Corn was ensiled for 9 wk without additives, with the addition of a bacterial inoculant or calcium formate. Ensiling affected both total FA content and FA composition of ryegrass silages. Total FA concentration increased (P < 0.001) during ryegrass ensiling. The proportions (g/100 g of total FA) of the major unsaturated FA, 18:3n-3 and 18:2n-6, were not affected (P > 0.05) by ensiling. However, their concentration (mg/g of DM) in silages was greater (P=0.017 and P=0.001, respectively) than in fresh ryegrass. Two 18:2 FA (trans-11,cis-15 and cis-9,cis-15) that were not originally present in the fresh ryegrass were detected in silages. Silage additives affected the FA composition of ryegrass silages, mostly by increasing the proportions of SFA, but not on total FA concentration. Ensiling did not affect (P=0.83) total FA content of corn silages; however, FA composition was affected, mostly by decreasing the proportions of 18:2n-6 and 18:3n-3. Silage additives had no effect on corn silage FA composition. Exposing corn silages to air resulted in no oxidation of FA or reduction in total FA content or composition. 相似文献
17.
Merry RJ Lee MR Davies DR Dewhurst RJ Moorby JM Scollan ND Theodorou MK 《Journal of animal science》2006,84(11):3049-3060
Two experiments were carried out to determine the effects of feeding grass silages differing in their water-soluble carbohydrate content, with or without red clover silage, on the efficiency of nutrient use. High-sugar grass, control grass, and red clover were ensiled in laboratory silos for use in an in vitro experiment (Exp. 1). For an in vivo experiment (Exp. 2), the same forage types were baled and ensiled. All silages were well preserved; within experiments the grass silages had similar composition, except for greater (P < 0.05) water-soluble carbohydrate concentrations in the high-sugar than the control grass silage. In Exp. 1, high-sugar grass, control grass, and red clover silages were fed alone or as mixtures (30:70, 50:50, or 70:30 on a DM basis, respectively) of each grass with the red clover silage to a simulated rumen culture system. There were no significant differences in microbial N flow or efficiency of microbial protein synthesis between individual forages. However, the corresponding values for the 70:30 ratio of high-sugar grass:red clover silage were greater (P < 0.05) than for the red clover silage. The value for the efficiency of N use (g of microbial N/g of feed N) was greater (0.86; P < 0.05) for high-sugar grass silage than the control grass silage. In addition, the high-sugar grass:red clover silage mixtures all gave greater (P < 0.05) values for the efficiency of N use than red clover silage alone; this difference was not achieved with the control grass mixture. Experiment 2 was an incomplete Latin square design conducted with 6 Here-ford x Friesian steers (163 +/- 5.9 kg of BW) with rumen and duodenal cannulas fed the following 5 silage diets: high-sugar grass silage; control grass silage; high-sugar grass and red clover silage (50:50 DM basis); control grass and red clover silage (50:50 DM basis); and red clover silage. Rumen NH3-N concentration was lowest (P < 0.05) with the high-sugar grass silage. Microbial N flows to the duodenum and efficiency of microbial protein synthesis were greater (P < 0.05) for steers fed the high-sugar grass silage than for control grass and red clover silages, and mixing red clover with grass silages increased (P < 0.05) these values compared with red clover silage alone. In both experiments, the efficiency of incorporation of silage N into microbial N was more than 20% greater (P < 0.05) for high-sugar grass than for control grass silage. These data suggest that grass silage with high-sugar content provides a forage-based strategy for balancing N and energy supply and improving the efficiency of use of grass silage N in the rumen. 相似文献
18.
苜蓿与直穗鹅观草混贮发酵品质研究 总被引：4，自引：0，他引：4
以苜蓿(Medicago sativa)与直穗鹅观草（Roegneria turczaninovi）为原料,按不同比例混贮,通过分析发酵品质和营养成分,优化混合青贮比例。结果表明,苜蓿青贮后干物质（DM）和中性洗涤纤维（NDF）含量增加,粗蛋白（CP）、 酸性洗涤纤维（ADF）、可溶性碳水化合物（WSC）含量降低,直穗鹅观草青贮后DM、NDF、CP及ADF含量增加,粗脂肪（EE）和WSC降低;混贮处理CP和Ca含量显著高于直穗鹅观草单贮,而显著低于苜蓿单贮,DM、NDF、ADF含量显著低于直穗鹅观草单贮;随直穗鹅观草在混贮比例中的提高,pH值呈降低趋势,混贮中乳酸占总酸含量居于两种牧草单贮之间,苜蓿与直穗鹅观草3∶7混贮乙酸含量占总酸含量显著高于其他处理（P＜0.05）,为33.9%,混贮处理丁酸产生较少;苜蓿与直穗鹅观草混贮氨态氮占总氮含量显著低于苜蓿单贮（P＜0.05）,且显著高于直穗鹅观草单贮（P＜0.05）;青贮后各处理乳酸菌数达到106 cfu/g（以鲜物质为基础）,较青贮前提高,各混贮处理乳酸菌和霉菌数高于两种牧草单贮;直穗鹅观草单贮发酵品质评分为97分,且氨态氮含量较低,为最佳处理。 相似文献
19.
Two silages were prepared from the primary growth (PG) of timothy-meadow fescue sward at early (E) and late (L) stage of growth. The subsequent regrowth (RG) areas were further harvested at early (EE and LE) and late (EL and LL) stages of growth resulting in six silages in total. The silages were fed ad libitum to 24 lactating Finnish Ayrshire cows and supplemented with 8 or 12 kg concentrate per day in a cyclic change-over experiment with four 21-day periods and 6 × 2 factorial arrangement of treatments. The quality of silages varied markedly within and between the harvests although variation was greater within PG than RG. Postponing the harvest in PG decreased silage dry matter (DM) intake by 0.48 kg and energy corrected milk yield (ECM) by 0.61 per 10 g decrease in silage D-value (concentration of digestible organic matter in DM), while responses and the range between the diets were clearly smaller when RG silages were fed. On average, ECM yield was higher when PG rather than RG silages were fed. The mean response to increased concentrate DM intake was 0.62 kg ECM using diets based on PG. The response increased with increasing growth stage of grass being 0.34 and 1.01 kg ECM / kg additional concentrate DM for E and L, respectively. The difference was mainly mediated by the differences in substitution rates (reduction in silage DM intake per increase in concentrate DM intake, kg/kg), which were 0.71 and 0.22 for E and L, respectively. The ECM response to increased concentrate allowance was on average greater when RG rather than PG silages (0.92 vs. 0.62 kg/kg concentrate) were fed. Milk production of dairy cows reflected the intake of metabolizable energy and no differences in the utilization of it were found between diets based on silages harvested from PG and RG. However, intake of RG silages was slightly lower than that of comparable PG silage, but definite reasons for that could not be identified. 相似文献
20.
不同添加剂对苜蓿青贮品质动态变化的影响 总被引：4，自引：1，他引：3
以生长第2年的紫花苜蓿为材料,设计4个试验组,每组分别添加不同水平甲酸（5．0,5．5和6．0mL／kg）、蔗糖（10,20和30g／kg）、发酵汁（1．5,2．0和2．5mL／kg）和不同比例无芒雀麦（25％,33％和50％）,同一水平设3个重复。分别在青贮第2、8、15和45d测定青贮料pH值、氨态氮／总氮（NH3-N／TN）及乳酸产量,以揭示不同添加物不同青贮时间对苜蓿品质动态变化规律的影响。结果表明：在青贮的整个过程,分别添加不同添加物的青贮料pH值呈不同程度下降,NH3-N含量则呈现上升趋势。5．5和6．0mL／kg的甲酸抑制青贮的自然发酵过程,在青贮第2、8、15和45d的乳酸测定值均显著低于对照。20和30g／kg的蔗糖为乳酸茵的生长繁殖创造了良好的条件,青贮各时间点NH3-N／TN较对照显著降低,青贮品质最好。综合分析,蔗糖应是苜蓿青贮的首选添加剂。 相似文献