首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
Alfalfa and orchardgrass herbages of similar digestibility were harvested at early and late maturity from primary growth and conserved as direct-cut silage using formic acid and formaldehyde simultaneously. Major compositional differences between the silages were lower NDF (principally hemicellulose) and a greater N content in alfalfa than in orchardgrass. An initial group of eight steers was slaughtered with a mean BW of 222 kg, and each of the four silages was fed to comparable groups of eight Holstein steers. Ad libitum DMI per unit of metabolic BW for alfalfa silages was 128% of that for orchardgrass silages. The ADG of steers fed alfalfa silages was 132% of that of steers fed orchardgrass silages. Despite greater ad libitum intake, total gut fill, as a percentage of BW, on alfalfa silages was 77% of that on orchardgrass silages. Daily empty BW gain of steers fed alfalfa silages was 158% of that of steers fed orchardgrass silages. Daily energy retention of steers fed alfalfa silages was 180% of that of steers fed orchardgrass silages. Steers fed alfalfa silages retained 140% more protein than steers fed orchardgrass silages did, but steers fed alfalfa silages retained only 71% as much protein energy relative to their total energy retention compared with steers fed orchardgrass silages. Differences in composition of daily energy retained were almost totally a result of differences in the total daily energy retention. Late alfalfa silage produced a greater daily gain than orchardgrass silage cut 2 wk earlier because greater intake compensated for lower digestibility.  相似文献   

2.
Alfalfa and orchardgrass herbages were each harvested at two maturities (May 22 to 25 vs June 5 to 7) in primary growth and directly ensiled with 5 kg of a mixture of 30% formic acid and 25% formaldehyde per metric ton of fresh herbage in upright conventional silos. Alfalfa silage contained less NDF (71%) and more N (150%) and hot-water-insoluble N (117%) than orchardgrass silage did. Major differences between silages were that orchardgrass contained 20.4 percentage units more NDF and 1.10 percentage units less N than alfalfa. The NDF increased 104% and total N decreased to 86% with advancing maturity. Twenty-eight yearling Holstein heifers (223 kg BW) were given ad libitum access to the four silages with trace mineral salt, and growth rate was measured in a 119-d period. Daily DE intake was 297 kcal/kg.75 BW for heifers fed alfalfa silage compared with 202 kcal/kg.75 BW for heifers fed orchardgrass silage. Daily gain was 992 g for heifers fed alfalfa compared with 661 g for heifers fed orchardgrass. Gross efficiency, or gain per unit of DE, was similar for heifers fed orchardgrass and alfalfa. Rate of gain was primarily a function of ad libitum intake of DE. Heifers fed alfalfa had greater plasma essential amino acid concentrations (122%) than those fed orchardgrass did. Late alfalfa produced greater ADG than orchardgrass harvested 2 wk earlier.  相似文献   

3.
Formaldehyde- and formic acid-treated alfalfa or orchardgrass silage were fed at 65 and 90 g DM/kg BW.75.d) to growing Holstein steers (209 +/- SE = 35 kg) fitted with permanent ruminal and duodenal cannulas in a 4 x 4 latin square. Alfalfa had higher (P less than .01) concentrations of cell solubles, total N and rumen-soluble N than did orchardgrass. Digestible energy (Mcal/d), total N and soluble N intake (g/d) were higher (P less than .05) for steers fed alfalfa than for those fed orchardgrass. Total duodenal OM, DM, NDF, N and non-NH3-N flows were greater (P less than .001) for steers fed alfalfa than for those fed orchardgrass and were greater (P less than .001) at high vs low intake. Duodenal bacterial N flow (g/d) was greater (P less than .001) for steers fed alfalfa than for those fed orchardgrass, and bacterial N synthesis (g/kg DM truly digested in the rumen) was 58 and 32, respectively (P less than .001). Ruminal concentrations of NH3-N (P less than .001) and VFA (P less than .05) were greater for steers fed alfalfa than for those fed orchardgrass. Total tract DM, energy and N digestibilities were higher (P less than .05) for steers fed alfalfa vs orchardgrass, whereas total tract NDF digestibility was lower (P less than .01). Tissue N retention tended to be greater (P less than .1) for steers fed alfalfa than for those fed orchardgrass. Regression analysis indicated that duodenal non-NH3-N flow was related to intake of metabolizable energy and soluble N (R2 = .939). Improved performance and higher efficiency of use of ME for tissue gain by steers fed alfalfa rather than orchardgrass is related to lower ruminal acetate:propionate, higher microbial efficiency and greater duodenal DM and N flows.  相似文献   

4.
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   

5.
不同添加剂对陇东紫花苜蓿青贮品质的影响   总被引：1，自引：0，他引：1  
生物添加剂在促进牧草青贮发酵过程中有益菌和酶的活性、提高消化率和改善发酵品质等方面发挥着重要作用。本研究以初花期刈割的第1茬陇东紫花苜蓿(Medicago sativa)为原料,分析不同添加剂(甲酸、蔗糖、EM菌液和纤维素酶)对青贮发酵品质的影响。结果表明,4种添加剂处理组苜蓿青贮饲料感官评定得分均高于无添加剂对照组,pH、乙酸和氨态氮(NH3-N)/总氮(TN)含量均显著(P<0.05)低于对照组,乳酸含量均显著(P<0.05)高于对照组,且未检测到丁酸和丙酸。4种添加剂处理组的粗蛋白质含量均显著(P<0.05)高于对照组,酸性洗涤纤维含量均显著(P<0.05)低于对照组。蔗糖组、EM菌液组和纤维素酶组的中性洗涤纤维含量均显著(P<0.05)低于甲酸组和对照组。粗灰分含量各组间无显著差异(P>0.05)。4种添加剂处理组的有氧稳定性均显著(P<0.05)高于对照组。上述结果说明,4种添加剂都可以提高陇东紫花苜蓿青贮的发酵品质、营养价值,延长有氧稳定性。但以纤维素酶组pH、乙酸和NH3-N/TN含量最低,乳酸含量最高,青贮发酵品质最佳,建议在生产实践中大量推广应用。  相似文献   

6.
Energy retention was compared in Holstein steers fed either alfalfa or orchardgrass silages for 164 d at either 65 or 90 g DM/kg.75 BW daily in a 2 x 2 factorial. Energy retention was estimated by slaughter-balance using an initial kill of eight steers at 216 kg and a final kill of eight steers per treatment at 326 kg. The ADG was not affected (P greater than .05) by silage, but steers fed alfalfa gained less (P less than .001) gut fill (they lost gut fill) and gained more (P less than .001) of the following than steers fed orchardgrass: empty body, 23%; fat, 50%; fat-free matter, 18%; protein, 16%; water, 17%; ash, 43%; gross energy, 31%; and carbon, 38%. With retained energy at 1.15 Mcal/d, retained energy was equally distributed between fat and protein. Increments of daily retained energy greater than 1.15 Mcal were deposited as 76% to fat and 24% to protein; this distribution was not affected by silage. The energy requirement for maintenance, with BW adjusted to equal gut fill, was not different (P greater than .05) at 130 kcal ME/kg.75 BW for steers fed alfalfa vs 125 for steers fed orchardgrass. Although not significant (P greater than .05), retained energy/ME intake above maintenance was 13% greater for steers fed alfalfa (.261) than for steers fed orchardgrass (.230), which supports the difference observed by calorimetry. The difference in dietary protein (25.6 vs 20.5%) did not contribute to the difference in energy retention because the differences in fat and protein retention could be explained totally by differences in daily energy deposition. The higher NDF of orchardgrass, or other fiber components, seems to be the most probable cause of its somewhat lower partial energetic efficiency relative to alfalfa.  相似文献   

7.
李真真  白春生  余奕东  玉柱 《草业学报》2016,25(11):167-172
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.
Three experiments were conducted to evaluate the effects of roughage source and concentration on intake and performance by finishing heifers. In Exp. 1, 12 medium-framed beef heifers (average BW = 389 kg) were used in three simultaneous 4 x 4 Latin square intake trials to evaluate the effects of dietary NDF supply from alfalfa hay, sudan hay, wheat straw, or cottonseed hulls fed in each Latin square at 5, 10, or 15% of dietary DM. Within each roughage concentration, roughage NDF accounted for the majority of variation in NEg intake/kg of BW0.75 among the roughage sources. Averaged across roughage concentrations, NEg intake/kg of BW0.75 tended to be greater (P < 0.10) when heifers were fed cottonseed hulls, sudan hay, or wheat straw than when they were fed alfalfa. In Exp. 2, six medium-framed beef heifers (average BW = 273 kg) were used in a 3 x 3 Latin square design to determine whether diets containing 10% (DM basis) alfalfa, cottonseed hulls, or sudan silage differed in eating rate. Average DM eating rates did not differ (P > 0.10) among roughage sources, which we interpreted to suggest that 90% concentrate diets containing alfalfa, cottonseed hulls, and sudan silage do not differ in the amount of chewing required during eating. In Exp. 3, 105 medium-framed beef heifers (average BW = 275 kg) were used in a 140-d finishing trial to evaluate three methods of dietary roughage exchange. Alfalfa at 12.5% of the dietary DM (ALF12.5) was used as a standard, and cottonseed hulls and sudan silage were each fed at three different levels: exchanged with ALF12.5 on an equal percentage DM basis, an equal NDF basis, or an equal NDF basis, where only NDF from particles larger than 2.36 mm (retained NDF) were considered to contribute to the NDF. No differences (P > 0.10) in ADG, DMI, gain:feed ratio, or NEg intake/kg of BW0.75 were detected between alfalfa and cottonseed hulls exchanged on an equal NDF basis. For sudan silage, exchanging with ALF12.5 on an equal retained NDF basis resulted in no differences (P > 0.10) in ADG, DMI, or NEg intake/kg of BW0.75. These data provide a preliminary indication that depending on the roughage sources evaluated, roughage NDF content and(or) roughage NDF from particles larger than 2.36 mm might provide a useful index of roughage value in high-concentrate finishing diets.  相似文献   

9.
Tifton 81 bermudagrass was harvested and ensiled either directly (D; 32.4% DM) or wilted (W; 44.1% DM). Four treatments applied to each harvesting method were 1) control (C), or no additive; 2) dried cane molasses (M) at 5% of DM; 3) microbial inoculant (I; Pioneer 1174); and 4) a combination of Treatments 2 and 3 (MI). Wilting reduced the rate of decline of silage pH (P = .001) and produced silages with greater lactic acid concentrations (P = .069), lower acetic acid (P = .001) and ammonia contents (P = .001), and greater in vitro OM (IVOMD; P = .001) and ADF digestibilities (IVADFD; P = .001). These high-quality silages were less stable under aerobic conditions, as evidenced by greater average temperatures (P = .001) and greater yeast and mold counts (P = .001). Adding M to D forage resulted in silage with lower pH (P = .001), greater concentration of lactic acid (P = .001), greater IVOMD (P = .092), and lower acetic acid (P = .009) and ammonia concentrations (P = .002) than inoculated D silage. Wilted silage treated with MI averaged lower pH (P = .025), greater lactic acid content (P = .001) and IVOMD (P = .001), and lower acetic acid (P = .001) and ammonia concentrations than silages treated with M or I alone. These results indicate that wilting improved bermudagrass silage the most, and that the addition of molasses and inoculant to wilted bermudagrass further enhanced silage quality.  相似文献   

10.
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   

11.
Our objective was to measure the utilization of energy (E) and N by Holstein steers when fed alfalfa and orchardgrass silages offered at 65 and 90 g DM/kg live weight (LW).75 daily. Twelve steers adapted to the Beltsville respiration chambers were assigned to three Latin squares with 42-d periods. Steers in one square had permanent catheters in the portal and two mesenteric veins. Energy and N balance were measured during a 7-d collection of feces and urine that included a 3-d measurement of respiratory exchange. Energy and N variables were not different between catheterized and uncatheterized steers. Apparent digestibilities of DM, OM, CP, neutral detergent solubles and permanganate lignin were higher (P less than .01) and digestibilities of NDF and ADF, hemicellulose and cellulose were lower (P less than .01) for steers consuming alfalfa compared to orchardgrass silage. When fed alfalfa, steers' daily gross energy intake, DE, urine energy, ME, heat production and tissue energy retention were greater (P less than .01) and fecal energy losses were less (P less than .01) than when they were fed orchardgrass. Partial efficiency of ME use for tissue energy (TE) was greater (P less than .01) for steers when fed alfalfa (46.1%) than when fed orchardgrass (35.6%). Apparent ME (kcal/LW.75) required for maintenance of TE was similar for steers when fed alfalfa (133.9) and orchardgrass (131.2) silages. Nitrogen retention (g/d) was 48% greater (P less than .01) for steers when fed alfalfa (30.6) than when fed orchardgrass (20.7). This study demonstrates that steers used ME from alfalfa more efficiently for TE deposition than ME from orchardgrass.  相似文献   

12.
This study was designed to separate the effect of fermentation quality on voluntary intake of grass silage from other feed factors affecting intake. Variations in DMI were quantified, and the impact on intake was modeled. The relationships between individual silage components and intake were examined. A partially balanced changeover experiment with 30 Norwegian Red steers (137 +/- 16.4 kg of BW) was carried out to determine the intake of 24 silages and of hay harvested from the same parent crop within 60 h. Five forages were fed at a time in each of five 3-wk periods. Every 3-wk period was preceded by 2 wk of feeding a standard silage. Silage DMI ranged from 1.79 to 2.65, with a mean of 2.38 kg x 100 kg of BW(-1) x d(-1). Hay DMI averaged 2.43 kg x 100 kg of BW(-1) x d(-1). Ranges (mean) for the composition of silages were as follows: DM, 166 to 237 (213) g/kg; water-soluble carbohydrates, 16.3 to 70.9 (33.0) g/kg of DM; acetic acid, 11.5 to 64.7 (28.6) g/kg of DM; propionic acid, 0 to 5.2 (1.0) g/kg of DM; butyric acid, 0 to 25.1 (6.0) g/kg of DM; lactic acid, 2.2 to 102 (49.3) g/kg of DM; and NH3-N (not corrected for additive-derived N), 89.3 to 255 (153) g/kg of total N. Silage DMI was closely (P < 0.05) related to DM, ADL, VFA, lactic acid, total acids, the lactic acid:total acids ratio, ADIN, NH3-N (not corrected), histamine, tryptamine, cadaverine, and the total sum of amines (the explained variation in intake ranged from 14 to 53%). The 2 best models describing silage DMI included concentrations in the silage of propionic acid, butyric acid, and lactic acid, and these models explained 75 and 84% of the variation in DMI. The strong correlation (r = 0.84, P < 0.05) between total NH3-N and butyric acid concentrations in silages indicates that these variables described the same variation pattern. The inclusion of NH3-N in the equations describing the effect of fermentation quality on DMI of low-DM grass silage was less useful than that of butyric acid. This was due to the confounded relationship between the NH3-N concentration in silages and the use of ammonium-containing preservatives and to difficulties in correcting for the added ammonium.  相似文献   

13.
Two experiments were conducted to evaluate digestion kinetics of alfalfa (Medicago sativa L.) substitution for grass hay in beef cattle. In Exp. 1, forage combinations evaluated in situ consisted of 0% alfalfa-100% big bluestem (Andropogon gerardi Vitman), 25% alfalfa-75% big bluestem, 50% alfalfa-50% big bluestem, and 100% alfalfa-0% big bluestem. Nonlinear regression was used to determine the immediately soluble fraction A, the potentially degradable fraction B, the undegraded fraction C, and the disappearance rate of DM and NDF. Dry matter fraction A increased linearly (P = 0.03), and DM and NDF fraction B decreased linearly (P = 0.01) with increasing alfalfa substitution. Rate of DM and NDF disappearance increased linearly (P /= 0.23) on total tract apparent digestibility of all nutrients except CP. Steers fed orchardgrass plus alfalfa had 33% greater (P = 0.01) total tract apparent digestibility for CP than those fed orchardgrass alone. Lag time of DM and NDF disappearance was not affected (P >/= 0.20) by alfalfa supplementation or intake level. Rate of DM and NDF disappearance of orchardgrass was faster (P 相似文献   

14.
选用辣椒采收后的秧秸为原料，试验设含水量（75％，65％和55％）和甲酸（0．5％，1．0％和1．5％）2个因素不同水平，塑料瓶青贮45d，研究水分和甲酸对辣椒秧青贮品质影响，结果显示：水分、甲酸及二者交互作用显著（P〈0．05）影响青贮辣椒秧的pH、NH3-N／TN、ADF、NDF和WSC含量；辣椒秧的青贮品质在中（65％）、高（75％）水分条件下优于低（55％）水分处理；甲酸的添加显著提高了WSC含量（P〈0．05），限制了丁酸的产生，降低了青贮料的PH和NH3-N／TN含量，并不同程度影响青贮辣椒的CP，ADF和NDF等养分含量。综合分析，含水量65％～75％，1．5％甲酸处理效果最佳。  相似文献   

15.
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   

16.
青贮菌剂在苜蓿裹包青贮中的应用效果   总被引：5，自引：0，他引：5  
在苜蓿裹包青贮中添加3种不同青贮菌剂JD6、MMD3、X3Q2,分析青贮苜蓿的营养品质,微生物数量以及瘤胃降解率的变化,以研究3种青贮菌剂在裹包青贮条件下对苜蓿青贮的影响。结果表明,青贮5个月后,添加青贮菌剂可以显著降低pH值(P<0.05)、NH3/TN值(P<0.05),减少丁酸含量(P<0.01),有利于保存青贮物的营养成分,提高青贮品质。添加青贮菌剂对青贮物的NDF、ADF含量没有影响,对青贮产物干物质和NDF的瘤胃降解率没有影响。添加青贮菌剂可以提高青贮产物中乙酸含量(P<0.05),减少酵母菌和霉菌数量(P<0.05)。3种青贮菌剂在苜蓿裹包青贮试验中,有利于抑制有害微生物,保存苜蓿营养成分,提高苜蓿青贮品质和有氧稳定性。  相似文献   

17.
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   

18.
Six nonpregnant Friesian heifers (516 kg avg BW) with ruminal and duodenal cannulas were used to examine intake of direct cut (DC) or wilted (W) grass silage in relation to chewing behavior, ruminal characteristics and site and extent of digestion. Dry matter content of the silages was 20.3% and 40.3%, and feed intake averaged 1.88% and 2.17% of BW (P less than .01), respectively. Mean ruminal osmolality was 291 mosm/liter for the DC and 318 mosm/liter for the W silage (P less than .05), with extreme values exceeding 350 mosm/liter for the W silage at 1 h to 2 h postfeeding. There was a shift from eating to ruminating on W silage associated with a longer duration of the average rumination bolus cycle (P less than .01). Duration of chewing time per kilogram of DM intake was 103.5 min and 91.7 min (P less than .05) for the DC and W silages, respectively. Fecal mean particle length was 2.2 times greater (P less than .01), accompanied by higher spread coefficients (P less than .001), for the W silage. No differences occurred between silages in ruminal digestibility of OM and NDF. In the total digestive tract, apparent digestibilities of OM and NDF were depressed after wilting grass prior to ensiling (P less than .01), but the proportion of digestible OM apparently digested in the rumen was .74 for both silages.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

19.
对所筛选的三种青贮菌剂和一种国外青贮菌荆分别添加于苜蓿青贮中,从苜蓿青贮营养成分、微生物数量、有氧稳良陛和瘤胃降解率多方面对这4种青贮菌剂进行综合评价。结果表明：自选青贮菌剂和商品青贮菌剂苜蓿青贮效果相近,各青贮菌剂添加处理的pH值、丁酸含量,酵母菌和霉菌的数量显著低于对照（p〈0．05）,提高了苜蓿青贮品质。添加三种自选青贮菌剂的苜蓿NH3／TN值显著低于对照（p〈0．05）,有效地抑制了蛋白质水解。添加自选青贮菌剂的青贮苜蓿在有氧的条件下,CO2产生量显著小于对照处理和商品青贮菌剂处理（p〈0．05）,可以提高青贮苜蓿的有氧稳定性。添加自选青筘菌剂和商品青贮菌剂对苜蓿青贮NDF、ADF含量没有显著影响,对青贮苜蓿DM和NDF的瘤胃降解率没有显著影响。  相似文献   

20.
Defined mixtures of two grass (orchardgrass, perennial ryegrass) and two legume (alfalfa, red clover) hays, harvested in two cuttings in 2 yr, were fed in digestibility, intake and mineral balance trials to wether lambs. Each mixture was fed in ad libitum amounts to six crossbred wether lambs weighing 35 to 45 kg. The effect of increasing proportion of legume in mixtures on dry matter digestibility (DMD), neutral detergent fiber digestibility (DNDF) and digestible dry matter intake (DDMI) differed with species combination. For all combinations, a quadratic regression (P less than .05) for DMD and DNDF indicated a small, negative associative effect for mixtures of grasses and legumes compared with pure species. Dry matter intake (DMI) showed a quadratic increase with level of legume inclusion, indicating a positive associative effect. The observed increase of DMI was approximately 6 to 7% over predicted values with 25 or 50% legume in the mixture. Intake of NDF also showed a quadratic response to level of legume, but lambs tended to eat to a fairly constant intake of 42 to 43 g NDF/kg wt.75. Mineral utilization (apparent absorption, retention) differed (P less than .05) with cutting but not species combination, and generally improved with increasing legume content in the mixture. With the exception of calcium retention (negative quadratic effect), there was little evidence for significant associative effects between grasses and legumes in mineral utilization.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号