Changes in the bacterial community and composition of fermentation products during ensiling of wilted Italian ryegrass and wilted guinea grass silages

To gain further insights into temperate and tropical grass ensiling, fermentation products and bacterial communities were examined at both the initial and late stages of ensiling of wilted Italian ryegrass and wilted guinea grass silages. 2,3‐Butanediol and ethanol fermentation were observed in wilted Italian ryegrass silage. Enterobacteria such as Rahnella sp. and Enterobacter sp. may have been involved in fermentation; however, alcohol production was intensified after the silage enterobacterial community overwhelmed the pre‐ensiled enterobacterial community. Pediococcus spp. appeared in silage stored for 4 months, when a significant increase in lactic acid content was seen compared with that at 2 months. Prolonged storage enhanced acetic acid fermentation in wilted guinea grass silage. The disappearance of Enterococcus sulfureus and appearance of Lactobacillus plantarum may have been associated with the increased acetic acid content. Although many species of enterobacteria were found in common between the pre‐ensiled crop and silages of Italian ryegrass and guinea grass, marked differences were seen in the type of fermentation from the initial stages. These results indicate that the bacterial community of pre‐ensiled crops may be immediately replaced by one that is adapted to ensiling environments, although metabolic changes may continue over the course of ensiling.     

Effects of ethanol,molasses and Lactobacillus plantarum on the fermentation quality,in vitro digestibility and aerobic stability of total mixed ration silages in the Tibetan plateau of China

In Tibet, it is common practice to make and relocate total mixed ration (TMR) silages before feeding due to the uneven distribution of forages temporally and spatially. This study was conducted to investigate the effects of Lactobacillus plantarum (L), molasses (M) or ethanol (E) on the fermentation quality and aerobic stability of local adaptive TMR silage. After 45 days of ensiling, pH and ammonia nitrogen in inoculated TMR silages were significantly lower than control. During the first 6 days of the aerobic exposure test, a small fluctuation in lactic acid concentration for all TMR silages was observed, and then silages with ethanol continued this trend, while lactic acid in silage without ethanol sharply decreased until the end of the aerobic exposure period. Meanwhile, pH gradually increased along the aerobic exposure; silages treated with ethanol showed lower pH after 9 days of aerobic exposure. The population of yeast gradually increased during 6 days of aerobic exposure, after that an accelerated rise was observed in TMR silages without ethanol. The combinational beneficial effect of L. plantarum and ethanol was found in combined addition of ethanol and Lactobacillus plantarum silages (EL), indicated by intermediate fermentation quality and higher aerobic stability.     

添加乙酸对西藏燕麦和紫花苜蓿混合青贮发酵品质和有氧稳定性的影响

为探讨不同水平乙酸对燕麦和紫花苜蓿(7∶3)混合青贮发酵品质和有氧稳定性的影响,试验设对照组和3个乙酸添加组(0.3%,0.4%,0.5%),青贮后第30,45和60天开窖取样,测定青贮饲料的发酵品质,同时60 d后打开剩余的所有实验室青贮窖,将青贮饲料暴露于空气中,测定青贮饲料有氧稳定性。结果表明,添加乙酸显著(P<0.05)降低了混合青贮饲料的pH,其中0.4%与0.5%乙酸处理组pH显著(P<0.05)低于0.3%乙酸处理组。青贮60 d后乙酸添加组乳酸含量显著(P<0.05)高于对照组,但处理组间差异不显著(P>0.05)。添加乙酸显著(P<0.05)降低了青贮过程中氨态氮/总氮,且氨态氮/总氮随着乙酸添加量的增加呈下降趋势(P>0.05)。各乙酸添加组水溶性碳水化合物均显著(P<0.05)高于对照组,其中0.4%乙酸添加组最高。在有氧暴露前10 d,各组pH和氨态氮/总氮基本保持稳定,其中乙酸添加组低于对照组。暴露10 d后各组pH均有上升,其中对照组显著(P<0.05)上升。在整个有氧暴露阶段,乳酸和水溶性碳水化合物含量逐渐下降,但各乙酸添加组均显著(P<0.05)高于对照组,其中0.4%乙酸添加组乳酸含量始终保持最高。综合考虑发酵品质和有氧稳定性,0.4%乙酸添加量最适宜。     

Effect of grape pomace on fermentation quality and aerobic stability of sweet sorghum silage

The objective of this study was to evaluate the effect of grape pomace (GP) with different adding levels (0%, 5%, 10% and 15%, fresh matter basis), alone (GP‐LAB) or in combine with an inoculant LAB (GP+LAB), on the fermentation quality and aerobic stability of sweet sorghum silage. After 90 days of ensiling in vacuumized mini‐silos, silages were subject to a 7‐day aerobic stability test, in which chemical, microbial and polyphenol composition were measured. In the GP‐LAB group, adding GP decreased (P < 0.05) concentrations of water‐soluble carbohydrate (WSC) and butyric acid in silage. In the GP+LAB group, adding GP increased (P < 0.05) concentrations of lactic acid, WSC and crude protein, decreased (P < 0.05) final pH value, NH₃‐N ratio and butyric acid concentration in silage. Polyphenol level was reduced (P < 0.05) after silage fermentation. During aerobic exposure, the fungi count, pH value and silage temperature increased (P < 0.05), the levels of lactic acid, acetic acid and polyphenols (quercetin 3‐O‐glucoside and quercetin 3‐O‐glucuronid) decreased (P < 0.05) in silage. GP+LAB treated silage had a lag phase for aerobic spoilage. When the fermentation products, microbial counts, chemical and polyphenol composition were considered, the use of 10% GP+LAB at ensiling could provide a valuable source for improved fermentation quality and aerobic stability of sweet sorghum silage.     

Fermentation quality and aerobic stability of mulberry silage prepared with lactic acid bacteria and propionic acid

The objective of this study was to examine the fermentation quality and aerobic stability of mulberry (Morus alba L.) silage prepared with lactic acid bacteria (LAB) and propionic acid (PA). The selected LAB strains Lactobacillus (L.) plantarum LC365281 (L1) and L. brevis LC365282 (L2), and commercial inoculant strains L. plantarum Gaofuji (GF) and L. buchneri Fresh (FR), and PA were used as additives for silage preparation. Silage treatments were designed as control, L1, L2, GF, FR, PA, PA + L1, PA + L2, PA + GF, or PA + FR. After 30 days of ensiling, the fermentation quality of silages treated with PA + L1 was improved, with a lower (p < 0.05) pH and NH₃‐N content than those of other treatments. During the aerobic exposure, the PA + LAB‐treated silages displayed an aerobic stability with stable pH value and lactic acid content. The results confirm that L. plantarum L1 and PA were the best additive combination for ensiling mulberry.     

A third-generation esterase inoculant alters fermentation pattern and improves aerobic stability of barley silage and the efficiency of body weight gain of growing feedlot cattle

This study investigated the effects of a mixed bacterial inoculant possessing ferulic acid esterase (FAE) activity on silage fermentation characteristics, aerobic stability, and growth performance of growing feedlot steers. Whole-crop barley (Hordeum vulgare L.) forage (35% DM) was chopped and ensiled without a silage inoculant (UN) or with a mixed bacterial culture containing 1.0 × 10(11) cfu/g of Lactobacillus buchneri LN4017 that produces FAE, 2.0 × 10(10) cfu/g of Lactobacillus plantarum LP7109, and 1.0 × 10(10) cfu/g of Lactobacillus casei LC3200 at a combined rate of 1.3 × 10(5) cfu/g of fresh forage (IN) in mini and Ag-Bag (Ag-Bag Int. Ltd., Warrenton, OR) silos. Silages from the mini silos were assessed for the effect of inoculation on fermentation characteristics and aerobic stability, whereas silages from Ag-Bags were used to formulate 2 barley silage-based total mixed rations (UN and IN) that were fed to growing feedlot steers for 112 d. The IN silage exhibited a homolactic fermentation during the first 7 d of ensiling as reflected by an increased (P ≤ 0.02) lactic acid concentration and an accelerated rate (P < 0.01) of pH decline. Thereafter, fermentation of IN silage became more heterolactic, resulting in greater concentrations of acetic acid (P < 0.01) and pH (P < 0.01) but less (P < 0.01) lactic acid than UN silage. Inoculation did not affect DM losses (P = 0.52) from mini silos. The IN silage remained stable during 21 d, but temperature and yeasts counts in the UN silage increased after 5 d of aerobic exposure. Growing steers fed the IN silage diet had superior (P = 0.03) feed conversion efficiency compared with those fed UN silage. Inoculation of whole-crop barley silage with a mixed culture of homolactic lactic acid-producing bacteria and FAE-producing L. buchneri at ensiling changed fermentation from a homolactic to a heterolactic form during ensiling and improved aerobic stability of the silage and efficiency of BW gain of growing feedlot steers.     

复合乳酸菌对全株玉米青贮及有氧暴露后微生物及饲料品质的影响

为探讨不同复合乳酸菌对全株玉米青贮及有氧暴露后青贮饲料中微生物数量及其发酵品质的影响,进一步筛选出可提高青贮饲料品质和有氧稳定性的复合乳酸菌接种剂,共设置3个不同组合乳酸菌分别添加全株玉米进行青贮,并设空白对照,测定青贮3、7、15和30 d,开袋有氧暴露1、3、7、15和30 d时微生物数量、发酵品质和营养成分的变化情况。结果表明,分别添加异型乳酸菌组合(Hetero)、同型乳酸菌组合(Homo)和同型+异型乳酸菌组合(Homo+Hetero)的各处理组均能有效地增加青贮过程和有氧暴露后饲料中乳酸菌的数量、乳酸(LA)和乙酸(AA)的含量,减少好氧细菌、酵母菌和霉菌数量,降低pH和氨态氮(NH₃-N)含量,减少粗蛋白(CP)损失,显著改善青贮饲料发酵品质,抑制青贮饲料有氧暴露后的二次发酵,其中Homo+Hetero效果最好,Homo处理组好于Hetero处理组。     

Effects of inoculants and environmental temperature on fermentation quality and bacterial diversity of alfalfa silage

To investigate the effects of inoculants and environmental temperature on fermentation quality and bacterial diversity of alfalfa silage, first‐cut alfalfa was ensiled with or without two screened lactic acid bacteria (LAB) strains, Lactobacillus plantarum, LP, and Lactobacillus casei, LC. Each treatment was divided into three parts and stored at 20°C, 30°C, 40°C, respectively. After 60 days ensiling, fermentation characteristics were measured and bacterial diversity was investigated by 16S ribosomal RNA gene sequencing using Illumina MiSeq platform. LP and LC decreased pH, coliform bacteria counts and increased lactic acid content at 20°C, and the two strains decreased pH, ammonia‐N concentration, coliform bacteria counts at 30°C. When the environmental temperature was 40°C, silage treated with LC showed lower LAB and coliform bacteria counts and higher lactic acid content than the untreated and LP treated silages. Butyric acid mainly appeared in silages stored at 40°C. The relative abundance of Lactobacillus in alfalfa silages stored at 20°C and 30°C was highest and increased after LP and LC were added. Garciella was another dominant genus in silages stored at 40°C. In conclusion, LP and LC improved fermentation quality of alfalfa silage by increasing Lactobacillus proportions at 20°C and 30°C; ensiling alfalfa at 40°C was difficult because of Garciella.     

晾晒时间和青贮时间对青贮玉米发酵品质的影响

目的 探究不同晾晒时间和青贮时间对全株青贮玉米发酵品质的影响。方法 以玉米（Zea mays L.）青贮品种“曲辰9号”为试验材料,将乳熟末期的青贮玉米全株收获粉碎后,在阴凉处分别晾晒0（对照,CK）、1、2、3、4 d,然后在塑料桶（5 L）中分别进行青贮,待青贮60、90、120 d时进行发酵品质的评定。结果 青贮玉米的含水量随着晾晒时间的增加而降低,在晾晒2、3、4 d后含水量显著（P<0.05）低于CK;用晾晒2、3、4 d的全株青贮玉米原料进行青贮,pH值显著（P<0.05）高于CK,晾晒2 d青贮120 d处理除外。晾晒时间对乳酸、丁酸、中性洗涤纤维（NDF）和酸性洗涤纤维（ADF）含量均产生显著（P<0.05）影响,青贮时间仅对乳酸、丁酸产生显著（P<0.05）影响,其中,乳酸含量随着青贮时间的延长而增加,丁酸含量在原料晾晒之后明显增加。CK处理中,青贮90、120 d的NDF含量显著（P<0.05）高于青贮60 d处理。利用氨态氮、乙酸、丙酸、丁酸开展V-Score分析,晾晒导致青贮玉米发酵品质降低,试验中品质较优的青贮为原料粉碎后未经晾晒的处理（CK）。结论 在未经晾晒处理下进行青贮60 d的青贮玉米,综合品质较高。在青贮玉米原料含水量为74%时,不建议粉碎之后通过晾晒降低含水量再青贮。     

多菌灵在果园白三叶青贮中的降解及其对微生物群落的影响

为了解白三叶青贮后不同浓度多菌灵农药的降解情况和果园喷施多菌灵对白三叶青贮过程中细菌多样性的影响,扩大具有农药残留的果园覆盖植物利用途径,在喷施不同浓度［2.0 （RU^-）,2.5 （RU）,3.0 g·L^-1 （RU⁺）］的多菌灵后进行白三叶青贮,以喷水为对照,发酵60 d。采用Miseq高通量测序技术,分别在青贮开始前、青贮第3和60天取样,对白三叶中细菌群落多样性进行研究。结果表明,青贮后多菌灵降解率达到59.6%以上,喷施量越高,降解率越高;多菌灵处理显著（P<0.05）增加了白三叶青贮发酵的乳酸、乙酸、丙酸含量,乳酸在多菌灵RU^-、RU、RU⁺浓度下分别增加了47.55%、63.24%、71.08%,乙酸分别增加了24.49%、44.90%、46.94%,丙酸分别增加了66.67%、187.50%、250.00%,有利于白三叶青贮饲料营养成分的保留;多菌灵喷施显著（P<0.05）改变了白三叶青贮菌群群落构成,增加了青贮的菌群丰度、多样性;多菌灵处理中乳球菌属、魏斯氏菌属、泛菌属、Rosenbergiella、假单胞菌属、寡养单胞菌属、肠杆菌属、芽孢杆菌属菌群丰度增加,不利于青贮发酵,但随着青贮时间的推移,寡养单胞菌属、肠杆菌属、芽孢杆菌属等菌群丰度减少。喷施多菌灵后有利于青贮发酵微生物菌群的丰度增加,对青贮发酵有害菌、多菌灵降解菌群丰度及青贮微生物多样性产生影响,青贮后多菌灵残留高于欧洲食品安全局规定的作物类动物饲料中农药最大残留量,达不到饲用标准。研究结果可为具有农药残留的白三叶青贮饲料的饲用安全性和果园覆盖植物资源的开发利用提供理论依据。     

Effects of chlorpyrifos and chlorantraniliprole on fermentation quality of alfalfa (Medicago sativa L.) silage inoculated with or without Lactobacillus plantarum LP

The effects of pesticides and Lactobacillus plantarum (LP) on fermentation quality of alfalfa (Medicago sativa L.) silage were investigated. Chlorpyrifos and chlorantraniliprole were sprayed on the surface of alfalfa plants at 658.6 and 45.0 g active ingredient/ha, respectively. Alfalfa plants were harvested on day 5 post‐application and ensiled with or without LP. Chlorpyrifos and chlorantraniliprole decreased the yeast count of alfalfa material (P < 0.05). Both pesticides increased the butyric acid content of alfalfa silage (P < 0.001). Chlorpyrifos increased pH and decreased lactic acid, acetic acid and short‐chain fatty acid contents (P < 0.05). LP decreased pH and butyric acid content, and increased lactic acid and short‐chain fatty acid contents of alfalfa silage treated with pesticides (P < 0.05). LP increased the concentration of chlorpyrifos residue in alfalfa silage (P < 0.05). Chlorpyrifos and chlorantraniliprole affected the microbial communities of the material before ensiling, especially coliform bacteria and yeast; the two pesticide residues were reduced after the fermentation of alfalfa silage and affected the fermentation process, whereas LP improved the fermentation quality of pesticides‐contaminated alfalfa silage and slowed down the dissipation of chlorpyrifos.     

Effect of varying fermentation conditions with ensiling period and inoculum on photosynthetic pigments and phytol content in Italian ryegrass (Lolium multiflorum Lam.) silage

This study aimed to investigate the effect of an ensiling period (Experiment 1) and adding lactic acid bacteria (LAB, Experiment 2) on the changes in carotenoid, chlorophyll, and phytol in ensiled Italian ryegrass (IR, Lolium multiflorum Lam.). In Experiment 1, the IR herbage ensiled into plastic bags was analyzed for the contents of photosynthetic pigments and phytol over a 5‐week period. During the ensiling process, the β‐carotene content decreased (p < .05), whereas the lutein content did not change. Although the chlorophyll content decreased (p < .05) after ensiling, the phytol content barely changed until week 5. In Experiment 2, IR herbage was ensiled without additive, as a Control, or with LAB for 60 days. The pH was lower (p < .05) and lactic acid content was higher (p < .05) for the LAB silage than for the Control. The chlorophyll content in silage was not affected by the LAB; however, the β‐carotene content was higher (p < .05) for the LAB silage than for the Control. Phytol and lutein contents in the herbage did not change after ensiling. These results indicate that phytol and lutein in IR herbage can be preserved well in silage, irrespective of their fermentation condition.     

笋壳替代全株玉米TMR发酵品质及有氧稳定性研究

本试验旨在探讨不同比例笋壳逐步替代全株玉米对全混合日粮(total mixed ration,TMR)发酵品质、营养价值和有氧稳定性的影响,确定适宜的笋壳替代水平。试验设对照组、15%笋壳组、25%笋壳组和35%笋壳组。青贮后第5, 7, 14, 30, 90天开窖取样,测定其发酵品质、营养成分及微生物变化;同时将青贮90 d的发酵TMR暴露到空气中,用多通道温度记录仪记录温度变化,并分别在有氧暴露第3, 6, 9和14天取样分析,评定其有氧稳定性。结果表明,尽管在整个青贮过程中随着笋壳替代比例的增加,各组乳酸含量逐渐降低,pH显著(P<0.05)升高,氨态氮/总氮逐渐上升,但青贮90 d后15%和25%组具有较高的乳酸含量(60.16~64.94 g/kg DM)、较低的pH(4.15~4.20)、氨态氮/总氮(55.56~58.73 g/kg TN)和极少量的丁酸含量(1.05~1.47 g/kg DM),仍显示良好的发酵品质。有氧暴露期间,对照组在有氧暴露第9天pH开始急剧上升,乳酸、乙酸和水溶性碳水化合物含量大幅度下降,发生有氧腐败,而笋壳处理组在有氧暴露14 d内pH缓慢上升,乳酸、乙酸和水溶性碳水化合物含量逐步降低,且温度也未超过环境温度2℃,与对照组相比有氧稳定性明显提高。其中15%组和25%组不仅有良好的发酵品质而且有氧稳定性高。从对笋壳资源的最大化利用角度出发,用25%的笋壳替代TMR中的全株玉米最为适宜。     

青贮密度和青贮时间对紫花苜蓿发酵品质及营养成分的影响

为研究不同青贮密度和青贮时间对紫花苜蓿(Medicago sativa L.)发酵品质及营养成分的影响,本试验以第二茬初花期(10%植株开花)刈割的紫花苜蓿为原料,采用双因素试验设计,分别设计青贮密度550,600和650 kg·m^-3以及时间30,60和120 d,对不同处理青贮料的发酵品质和营养成分进行分析。结果表明：除乙酸和粗蛋白(Crude protein, CP)含量外,青贮密度和时间的交互作用显著影响了苜蓿的发酵品质和营养成分(P<0.05);与密度为650 kg·m^-3的处理组相比,密度为600 kg·m^-3的处理组青贮30和60 d后,乳酸和干物质(Dry matter, DM)含量增加,酸性洗涤纤维(Acid detergent fiber, ADF)和可溶性碳水化合物(Water soluble carbohydrate, WSC)含量减少;在密度为600 kg·m^-3下,与青贮30 d相比,青贮60 d的样品中乳酸、乙酸、DM,CP和粗脂肪(Ether extract, ...     

砂仁精油对紫花苜蓿青贮品质的影响

为了研究砂仁精油(Amomum villosum Lour. essential oil,AVEO)对紫花苜蓿(Medicago sativa L.)青贮发酵品质和营养品质的影响,本试验分别在紫花苜蓿中添加了0.5% AVEO和1% AVEO进行青贮,以添加等量蒸馏水的紫花苜蓿为对照组(CK),在15 d和30 d开袋取样,并对青贮的发酵参数和营养成分进行分析。结果表明,AVEO显著降低了紫花苜蓿青贮的pH值(P<0.01),提高了干物质含量、干物质回收率和真蛋白含量(P<0.01)。此外,在青贮第15 d,1% AVEO显著减少了紫花苜蓿青贮中的大肠杆菌的数量(P<0.05);在青贮第30 d,1% AVEO显著提高了紫花苜蓿青贮的乳酸的含量(P<0.05)。因此,添加AVEO对紫花苜蓿进行青贮有利于改善紫花苜蓿青贮的发酵品质和营养品质。     

添加糖蜜和乙酸对西藏发酵全混合日粮青贮发酵品质及有氧稳定性影响

为研究乙酸和糖蜜对发酵全混合日粮(FTMR)品质及有氧稳定性的影响,试验以全混合日粮(TMR)为发酵原料,设对照组、乙酸(A)、糖蜜(M)、乙酸和糖蜜组合添加(AM)4个处理,发酵45 d后分析FTMR的发酵品质,同时将所有FTMR暴露到空气中,分别在第6,9和12天取样评定其有氧稳定性。结果表明,与对照相比,A和AM组降低了乳酸含量(P>0.05),各组仅检测到微量的丙酸、少量的丁酸和较低的氨态氮/总氮,表明各组FTMR发酵品质均良好。有氧暴露6 d后,各组乳酸、乙酸和水溶性碳水化合物含量均呈不同程度的下降,对照和M组pH值在第12 天显著(P<0.05)上升至5.70和6.50,具有较高的氨态氮/总氮和酵母菌数量。而A和AM组乳酸含量均呈先上升后下降的变化趋势,且好氧性微生物和酵母菌数量在整个有氧暴露的过程中始终维持在较低水平,有氧暴露12 d后pH值仍维持在4.50左右,延长了有氧稳定时间。综合考虑,为了获得品质优良的FTMR饲料,可在TMR中添加0.3%乙酸,既不影响发酵品质,也可提高其有氧稳定性。     

添加剂对玉米秸秆和莴笋叶混贮品质的影响

借鉴青贮原理,将干玉米秸秆与水分含量较高的废弃莴笋叶进行混贮,分析不同添加剂对二者混贮品质的影响。设置了对照组(CK)、德氏乳杆菌组(LD)、甲酸组(FA)、复合添加剂组(LD+FA)4个处理,每个处理3次重复,连续贮存50 d,每间隔10 d对干物质和木质纤维组分含量、发酵品质及微生物数量进行分析,比较筛选适宜的添加剂。结果表明,50 d贮存期内,与CK组相比,FA组的干物质损失最小,且添加甲酸青贮后显著降低了纤维素、半纤维素和酸性洗涤木质素、氨态氮/总氮含量和青贮pH(P<0.05),乳酸含量显著增加(P<0.05),V-score评分表现良好;LD组的干物质损失、氨态氮/总氮含量显著高于CK组(P<0.05),青贮pH均高于4.2,V-score评分表现最差;LD+FA组在前30 d的贮存品质较好,之后氨态氮/总氮含量显著增加(P<0.05),贮存品质变差。从延长贮存时间和提高贮存品质等角度考虑,甲酸可以作为干玉米秸秆与莴笋叶混合贮存的添加剂,但应用过程中需要注意成本问题。     

Effects of hybrid and bacterial inoculation on fermentation quality and fatty acid profile of barley silage

This study estimated the effects of hybrid and bacterial inoculant on fermentation quality and fatty acid profile of barley silages. Yuyeon (Silkless) and Youngyang (Silking) barley hybrids were harvested at 24.9 and 27.1% dry matter, respectively, and chopped to 10 cm lengths. Each hybrid was treated with or without an inoculant (2 × 10⁴ colony‐forming units/g of Lactobacillus plantarum). A total of 48 silos were prepared in an experiment with a 2 × 2 (hybrid × inoculant) treatment arrangement with four replications and three ensiling durations (2, 7 and 100 days). After 100 days of ensiling, Yuyeon silage had higher (P < 0.05) in vitro dry matter digestibility and C18:3n‐3 than Youngyang silage. Youngyang silage had higher (P < 0.05) acetic acid and C18:2n‐6 than Yuyeon silage. Inoculation reduced the C18:3n‐3 concentration of both hybrids and increased (P < 0.05) the C18:2n‐6 of Youngyang. However, fermentation quality was not improved by the inoculant. These results indicate that Yuyeon hybrid might have better potential benefits on animal performances due to its smooth awn and silkless nature, and higher in vitro dry matter digestibility. Its higher C18:3n‐3 would be better for improving fatty acid profile of meat or milk than Youngyang hybrid.     

Comparative analysis of ensiling characteristics and protein degradation of alfalfa silage prepared with corn or sweet sorghum in semiarid region of Inner Mongolia

This study was conducted to evaluate silage fermentation and protein degradation of alfalfa prepared with corn or sweet sorghum (SS) at different mixing ratios. The chemical composition, ensiling characteristics, and protein degradation of alfalfa prepared with and without corn or SS at mixing ratios of 7:3, 1:1, and 3:7 on a fresh matter (FM) basis were studied. The alfalfa had the highest crude protein (CP) content and lactate buffering capacity (LBC), but lower water‐soluble carbohydrate (WSC) content than corn and SS. After 60 days of ensiling, the corn and SS silages had good quality, with lower pH and ammonia‐N content, and higher dry matter (DM) content than the alfalfa silages. In the alfalfa and corn mixture silages, the DM contents linearly increased with an increase in the proportion of corn, while the pH, non‐protein N (NPN), ammonia‐N, and peptide‐N contents linearly decreased. In the alfalfa and SS mixture silages, the DM and NPN contents linearly increased with an increase in the proportion of SS, while the pH, lactic acid, and ammonia‐N contents linearly decreased. This study suggests that alfalfa silage prepared with corn has more positive effect on fermentation quality and inhibiting protein degradation than addition of SS.     

不同乳酸菌添加剂对青贮黑麦草和青贮玉米发酵产物和有氧稳定性的影响

在青贮黑麦草(Lolium perenne)和青贮玉米(Zea mays)中添加鼠李糖乳杆菌和布氏乳杆菌,研究其对发酵产物与有氧稳定性的影响.青贮饲料贮藏时间为14,56和120 d.无添加青贮黑麦草发酵产物中乙醇含量较多,在14 d开封时,乙醇和2,3-丁二醇含量为乳酸和挥发性脂肪酸总和的7倍.添加鼠李糖乳杆菌与布氏乳杆菌可以抑制乙醇型发酵,使乳酸型与乙酸型发酵占主导.无添加青贮黑麦草与添加鼠李糖乳杆菌的黑麦草发生了有氧腐败,但是添加布氏乳杆菌的黑麦草保持了有氧稳定.在青贮玉米中,添加鼠李糖乳杆菌未影响发酵品质,但添加布氏乳杆菌增加了发酵产物中乙酸含量,降低了乳酸含量.添加布氏乳杆菌的青贮玉米从56 d开封开始保持了有氧稳定,其它组在120 d开封时保持了有氧稳定,所有组乙酸含量都增加.