不同菌剂添加量对牧草青贮料有机酸的影响

以锡林郭勒盟典型草原牧草为青贮原料,在青贮其他条件一致的情况下,试验就菌剂添加量设计了3个处理,分别为（0．25g／kg、0．50g／kg、1．00g／kg）通过比较不同处理天然牧草青贮料之间有机酸的组成成分含量以及对有机酸的影响,为研究青贮饲料发酵特性和评价青贮饲料的品质提供理论依据。结果表明：天然牧草青贮后乳酸、乙酸和丙酸的含量在菌剂添加量为0．50g／kg时达到最大值,乳酸的含量为63．74mmol／g,乙酸为30.08mmol／g、丙酸为36．54,mmol／g,而丁酸的含量则降低到0mmol／g。     

不同青贮处理方式对甘蔗尾叶饲用品质的影响

试验旨在研究不同青贮方式对其青贮后甘蔗尾叶饲用品质的影响。不同青贮方法包括直接青贮甘蔗尾叶(对照组);分别添加0.6%、1.2%尿素青贮;添加0.1、0.2、0.4g/kg纤维素酶青贮;添加0.3、0.6g/kg甲酸青贮;添加0.5、1.0g/kg丙酸青贮。对青贮后甘蔗尾叶进行感官评定、常规营养成分分析和养分瘤胃降解率分析。结果表明,添加不同浓度的尿素、纤维素酶、甲酸、丙酸青贮甘蔗尾叶,与对照组直接青贮相比,青贮品质均有提高,瘤胃DM、NDF降解率有所提高。添加纤维素酶组的CP降解率显著高于其它处理组(P0.05),添加1.0g/kg丙酸青贮甘蔗尾叶后DM、NDF、OM的降解率显著高于其它组(P0.05)。试验结果表明,添加纤维素酶或1.0g/kg丙酸青贮,可以显著提高甘蔗尾叶饲用品质。     

添加甲醛对草木樨青贮品质的影响

在刚收获及收获后经过8h和30h晾晒的初花期草木樨(干物质含量分别为27．36％、38．69％和44．98％)青贮料中，加入甲醛(添加量分别为1．5g／kg、3．0g／kg和4．5g／kg)进行青贮。结果表明，草木樨低水分(DM为44．98％)青贮可以使青贮料的氨态氮含量降低，并保存更多的干物质、粗蛋白质和可溶性糖。草木樨添加甲醛青贮有助于降低青贮料的氨态氮含量，并保存较多的可溶性糖和粗蛋白质；但低水平(1．5g／kg)甲醛处理使青贮料发酵不良；草木樨青贮添加3．0g／kg和4．5g／kg的甲醛效果最好，晾晒30h添加4．5g／kg的甲醛效果最好。     

不同青贮方法对全株玉米型日粮发酵品质的影响

文章旨在探讨用不同添加剂对全株玉米型日粮化学成分、pH和发酵品质的影响。试验将常用的肉牛全混合日粮分成16份,每份1 kg,随机分为4组,每组4份,对照组不添加任何添加剂进行普通发酵,处理1组添加20 g/kg糖蜜,处理2组添加3 g/kg丙酸,处理3组为联合发酵组(20 g/kg糖蜜+3 g/kg丙酸),青贮6周后,收集样品进行后续分析。结果:糖蜜青贮组干物质、乳酸和乳酸菌含量较对照组分别显著提高11.94%、19.82%和23.20%(P<0.05),但处理组丁酸、中性洗涤纤维和酸性洗涤纤维含量显著低于对照组(P<0.05)。对照组全株玉米型日粮青贮7和14 d后pH显著降低(P<0.05)。青贮1 d和14 d,糖蜜组乳酸含量较对照组分别显著提高19.93%和71.77%(P<0.05),而青贮7 d,丙酸组乳酸含量较对照组显著提高17.42%(P<0.05)。青贮1、7和14 d,糖蜜组和丙酸组全株玉米型日粮氨氮与总氮比值均显著降低(P<0.05)。青贮1和7 d后糖蜜组全株玉米型日粮中乳酸菌含量均显著高于对照组(P<0.05),青贮14 d后,处理组乳酸菌数量较对照组分别显著降低了10.75%、16.05%和17.17%(P<0.05)。结论:在全株玉米型日粮中添加20 g/kg糖蜜可以提高青贮产物乳酸含量,同时改善发酵好氧稳定性,添加3 g/kg丙酸发酵虽然降低了青贮过程中乳酸产量,但提高了发酵产物水溶性碳水化合物含量。     

不同青贮添加剂对去油芳樟枝叶青贮饲料营养成分、青贮发酵品质和瘤胃体外发酵特性的影响

本试验旨在探讨不同青贮添加剂对去油芳樟枝叶青贮饲料营养成分、青贮发酵品质和瘤胃体外发酵特性的影响.采用单因素试验设计,共设4个组:对照组(不添加任何青贮添加剂)、葡萄糖组(添加20 g/kg葡萄糖)、混合有机酸组(按照7:1:2的体积比例将甲酸、乙酸和丙酸混合,添加6 mL/kg)和纤维素酶组(添加2 g/kg纤维素酶...     

不同青贮添加剂对苜蓿青贮品质的影响

以紫花苜蓿为材料,采用随机区组设计,研究不同添加水平添加剂,甲酸（5．0ml／kg、5．5ml／kg和6．0ml／kg）、蔗糖（10g／ks、20g／kg和30g／ks）、发酵汁PFJ（1．5ml／kg、2．0ml／kg和2．5ml／kg）和不同比例无芒雀麦（25％、33％和50％）混合青贮对青贮pH值、氨态氮（NH3-N）含量及乳酸产量的影响。结果表明：蔗糖（30g／ks）添加效果最好,甲酸（6．0ml／kg）次之,以下依次为混合青贮、直接青贮和PFJ青贮。     

添加剂对呼伦贝尔草甸草原牧草青贮品质与体外消化率的影响

以呼伦贝尔草甸草原牧草为材料,分别添加1ml/kg、1.5ml/kg、2ml/kg甲酸,1ml/kg、1.5ml/kg、2ml/kg丙酸,0.02g/kg、0.04g/kg、0.06g/kg纤维素酶,0.2g/kg、0.4g/kg、0.6g/kg乳酸菌剂后青贮,60d后开袋测定发酵品质、营养品质和体外消化率。结果显示:(1)添加甲酸1.5ml/kg后,青贮pH值、AN/TN含量显著降低,LA、CP、WSC含量显著升高(P0.05)。(2)添加2ml/kg丙酸后,青贮pH值、AN/TN均显著低于CK,LA含量显著高于CK(P0.05)。(3)添加0.06g/kg纤维素酶后,青贮饲料品质得到有效改善,pH值、AN/TN显著降低,LA、CP、WSC含量显著升高(P0.05)。(4)添加0.5g/kg乳酸菌剂后,青贮pH值、AN/TN、CP含量显著降低,未检测出BA成分,PA、WSC含量显著增加(P0.05)。综合考虑,添加剂分别为甲酸1.5ml/kg、丙酸2ml/kg、纤维素酶0.06g/kg、乳酸菌剂0.4g/kg,可在促进天然牧草青贮发酵的同时有效保存天然牧草的营养成分。     

处理方式对天然牧草青贮料有机酸的影响

以锡林郭勒盟典型草原牧草为青贮原料,设计不同含水量、不同菌剂添加量、不同密度3种处理方式,通过比较不同处理间有机酸的组成成分含量以及对有机酸的影响,为研究青贮饲料发酵特性和评价其品质提供理论依据。结果表明:天然牧草青贮后乳酸的含量在天然牧草含水量为65%~70%时达到最大值46.74 mmol/g,乙酸和丙酸的含量随天然牧草含水量的增加而增加,丁酸的含量则相反;天然牧草青贮后乳酸、乙酸和丙酸的含量在菌剂添加量为0.50 g/kg时达到最大值,乳酸的含量为63.74 mmol/g,乙酸为30.08 mmol/g、丙酸为36.54 mmol/g,而丁酸的含量则降低到0 mmol/g;天然牧草青贮的密度达到300 kg/m³时,天然牧草青贮料中的有机酸组成最佳。     

添加葡萄糖对木薯叶青贮品质和营养成分的影响

为改善木薯叶青贮品质,研究葡萄糖对木薯叶青贮品质及营养成分的影响,以确定青贮木薯叶葡萄糖最佳添加量。以华南7号木薯幼嫩茎叶为原料,设对照组(直接青贮)和添加5、10、20和40g/kg的葡萄糖处理组,青贮30d后分析木薯叶青贮饲料pH、乳酸、乙酸、丙酸、丁酸含量以及主要营养成分含量。结果表明:木薯叶直接青贮品质较差,添加葡萄糖处理与对照相比显著降低青贮饲料的pH和丁酸含量(P<0.05),降低中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)含量(P<0.05),提高了饲料相对值(RFV)。研究结果表明,添加葡萄糖可以改善木薯叶青贮品质并提高营养价值,综合考虑葡萄糖添加量为20g/kg效果最好。     

丙酸铬对猪生产性能和胴体品质的影晌研究

本试验旨在研究在猪日粮中添加丙酸铬对其生产性能和胴体品质的影响。将108头初始体重为29±3kg的约克夏猪随机分组。共包含2个不同水平含量的丙酸铬（0和2001μg／kg）和3个不同来源的油脂组（不添加油脂、优质油脂和普通油脂）。每个处理组设置6个重复,每个重复3头猪。猪的生长育成共分成4个阶段。各处理组日粮组成具体为：1）对照组不添加丙酸铬和油脂：2）对照组基础上添加4％的普通油脂：3）对照组基础上添加4％的优质油脂;4）对照组基础上添加200／μg／kg的丙酸铬：5）日粮2基础上添加200μg／kg的丙酸铬;6）日粮3基础上添加200μg／kg的丙酸铬。试验结果显示,丙酸铬的添加几乎没有影响猪的生产性能．但却降低了猪第10肋骨的背膘厚度（P=O．05）,而油脂的添加可明显提高猪的饲料报酬（G：F）和降低猪的ADFI（P=0．03）。     

两种防霉剂与丙酸的组合对青贮牧草根霉菌毒力的研究

采用抑菌圈法研究了75%百菌清、50%多菌灵与99.5%丙酸在不同浓度下组合对高寒地区青贮饲草根霉菌的毒力。结果表明:丙酸(200mg/kg) 百菌清(400mg/kg)、丙酸(200mg/kg) 多酸灵(300mg/kg)、丙酸(100mg/kg) 多菌灵(300mg/kg)组合对根霉菌的毒力没有显著差异,但其毒力均极显著地高于其他处理;以丙酸(200mg/kg) 百菌清(400mg/kg)组合对青贮牧草根霉菌的抑菌作用最佳,其毒力分别是丙酸(200mg/kg) 多菌灵(300mg/kg)组合的1.05倍和丙酸(100mg/kg) 多菌灵(300mg/kg) 组合的1.20倍。     

不同能量水平对断奶至2月龄肉兔生产性能、氮利用、免疫和盲肠发酵的影响

将 8 0只断奶肉兔随机分成 5组 ,饲喂 5种消化能不同 (9.4 6 ,10 .4 6 ,11.4 6 ,12 .4 6和 13.4 6MJ/kg)的日粮。结果表明 :能量水平对 2月龄体重、断奶至 2月龄日增重无显著影响 (P >0 .0 5 ) ,2月龄体重、断奶至 2月龄日增重以能量水平为 10 .4 6MJ/kg时最高 ,分别为 16 38g和 2 5g;能量消化率和脾脏指数随能量水平不同而变化差异显著(P <0 .0 5 ) ;盲肠pH值、NH3 N浓度、丙酸含量、TVFA和乙酸 /丙酸比组间差异极显著 (P <0 .0 1) ,乙酸和丁酸含量组间差异显著 (P <0 .0 5 )。以日增重、蛋白质消化率等指标为依据 ,断奶至 2月龄肉兔适宜消化能水平为 10 .4 6MJ/kg。     

Devitalization of salmonellae in fish meals with propionic acid

Animal protein feeds are regarded as a potential source of salmonellae for the animal and human population. Decontamination is carried out by various methods. At the present time, propionic acid is recommended for this purpose but different levels of concentration have been given by various authors. In our experiments broth cultures of the following serotypes were used for artifical contamination: Salmonella typhimurium, S. taksony and S. senftenberg. The infected fish meal always contained 200,000 salmonellae in 1 g. The addition of 3% propionic acid resulted in an immediate devitalization of salmonellae. The addition of 2% propionic acid caused devitalization within 49 days. Salmonella senftenberg was found to be the most resistant of the three serotypes tested. The active substance must be perfectly homogenized. The addition of 0.3% propionic acid has proved effective in broth.     

Effect of organic acids on numbers of yeasts and mould fungi and aerobic stability in the silage of corn

The aim of these studies was to assess the effect of chemical conservants (FA = formic acid, PA = propionic acid, FPA+i = formic acid, propionic acid and ammonium ions) on the cell counts of yeasts and mould fungi in silage. The silage was prepared from corn (Zea mays L), cultivar Buran FAO (240). The effect of the applied conservants on silage aerobic stability was also assessed. The performed chemical analyses comprised the determination of: the content of dry matter (DM), lactic acid (LA), acetic acid (AA), ethanol, water soluble sugars (WSC), crude protein (CP) and pH. The applied preparations were found to reduce the number of yeast and mould fungi cells in all the examined silages. The growth of fungi was inhibited most strongly by the FPA+i preparation (containing a mixture of formic and propionic acids and ammonium ions). The yeast cell counts dropped (P<0.05) from 8.50 107 CFU g(-1) silage in the control (CCS = control corn silage) to 2.60 107 CFU g(-1) in silage treated with FPA+i, whereas counts of the mould fungi cells - from 15.20 104 CFU g(-1) silage in the control to 4.60 104 CFU g(-1) in silage treated with FPA+i. The applied conservants increased (P<0.05) the content of DM from 255.00 g kg(-1) in control to 266.60 g kg(-1) with PA, WSC from 27.10 g kg(-1) DM to 30.50 g kg(-1) DM with FPA+i and ethanol from 9.10 g kg(-1) DM to 11.21 g kg(-1) DM with FPA+i in the silage. The additives decreased concentrations of lactic acid, acetic acid and crude protein concentration after opening the barrels. The diversifying factors decreased the pH value in the examined silage. The experimental conservants were found to improve the aerobic stability of silages after 7 days of air exposure.     

The effect of fermentation quality on the voluntary intake of grass silage by growing cattle fed silage as the sole feed

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.     

玉米秸秆酶解液发酵生产丙酸联产益生菌

分别以葡萄糖和玉米秸秆酶解液作为碳源,研究了利用玉米秸秆酶解液发酵生产丙酸的可行性。考察了秸秆酶解液糖浓度对丙酸发酵的影响,建立了丙酸和益生菌联产的补料分批发酵工艺,有效解决了高糖秸秆酶解液对丙酸发酵的抑制问题,提高了丙酸产量和菌体量。补料分批工艺:初始糖浓度为15 g/L,通过间歇补料维持葡萄糖浓度在15 g/L以下,用氨水调节pH为6.8~7.0,发酵周期130 h,丙酸产量可达19.97 g/L,丙酸产生速率为0.15 g/L.h,活菌数达到6.90×1012 cfu/mL。     

添加不同水平阴离子盐对人工瘤胃液理化指标的影响

本试验采用人工瘤胃模拟装置研究了添加不同水平阴离子盐0、-50mEq/kg、-100mEq/kg和-150mEq/kg的日粮对瘤胃消化代谢的影响。通过对瘤胃液pH值、NH3-N、VFA浓度的测定,结果表明,添加阴离子盐水平在-150mEq/kg内,对瘤胃pH值和氨氮浓度有一定影响,但差异不显著(p>0.05);当添加水平在-100mEq/kg和-150mEq/kg时,对乙酸浓度、丙酸浓度及乙酸/丙酸比例影响差异均为显著(P<0.05)。     

Disappearance and passage of propionic acid from the rumen of the beef steer

Studies were conducted to define steady state pH, propionic acid concentrations and fluid turnover in the rumen of steers fed every 3 h and to determine whether rates of ruminal propionic acid disappearance were linearly related to their in situ production rates. Ruminally fistulated beef steers (326 +/- 11 kg; n = 3) were fed eight times daily a 54% mixed hay: 46% corn-based concentrate diet to meet maintenance energy requirements. Maximal acceptable variations from the mean at steady state conditions of pH, propionic acid concentrations and specific activity, and liquid flow (Cr marker concentrations) were defined as 4%, 20%, 30% and 10%, respectively, across 4 h of observation. In situ production of propionic acid, determined by pulse-continuous infusion of 1-14C-propionic acid, was 142 mmol/h (CV = 8.4%). The ruminal half-life of propionic acid was estimated to be 1.5 h and the liquid flow rate was 3.8 liters/h. Propionic acid production rates subsequently were elevated by continuous intraruminal infusion of buffered propionic acid. Irrespective of production (basal and infusion) rate, approximately 66% disappeared (i.e., presumed absorption) and 34% passed from the rumen to the lower tract in the liquid phase. Ruminal disappearance of propionate was linearly related with its production rate, and propionate concentrations and production rates also were linearly related. Liquid passage was linearly related to production rate, but there was insufficient evidence to conclude that fractional dilution rate or ruminal volume were similarly related. When ruminal production of propionic acid is elevated, the rumen has additional absolute capacity to remove propionate, but the fractional removal appears to be constant. The digestive tract distal to the rumen is likely an important site of propionate absorption in cattle when propionate production is high.     

Influence of fibrolytic enzymes in total mixed ration containing urea-molasses-treated sugarcane bagasse on the performance of lactating Holstein–Friesian crossbred cows

The aim of this study was to determine the effect of different levels of fibrolytic enzyme on nutrient utilization and milk production in dairy cows. Four multiparous early-to-mid-lactation Holstein–Friesian crossbred cows were randomly allocated in a 4 × 4 Latin square design. Cows were fed a balanced total mixed ration (TMR) on a dry matter (DM) basis containing 0, 1.2, 2.4, and 3.6 g/kg DM of fibrolytic enzyme in TMR, where the TMR comprises 60% concentrate supplemented with a fibrolytic enzyme at 0, 2, 4, and 6 g/kg DM of concentrate, and 40% urea-molasses-treated sugarcane bagasse (UMSB) was used as a roughage source. Fibrolytic enzyme supplementation in TMR containing UMSB did not affect dry matter intake (DMI) of dairy cows (p > 0.05). There was a quadratic effect of fibrolytic enzyme levels on the digestibility of DM, organic matter (OM), neutral detergent fiber (NDF), and acid detergent fiber (ADF) (p < 0.05), and the maximal response was reached at 1.2–2.4 g/kg DM of fibrolytic enzyme added in the TMR. Furthermore, 3.5% fat-corrected milk, milk fat, total volatile fatty acids, and propionic acid were greater in a cow fed with 1.2–2.4 g/kg DM of fibrolytic enzyme, resulting in a lower ratio of acetic acid to propionic acid (p < 0.05). In conclusion, adding a fibrolytic enzyme in TMR containing UMSB improved nutrient utilization, rumen fermentation, and milk production of lactating dairy cows.