为研究不同组合酶菌制剂处理对水稻秸秆青贮饲料的营养成分、发酵品质及瘤胃降解特性的影响,试验共设9个处理组:对照组(CK)、复合酶制剂处理组(C)、果胶酶+漆酶处理组(PL)、复合酶制剂+果胶酶+漆酶处理组(CL)、植物乳酸杆菌处理组(LP)、布氏乳酸杆菌处理组(LB)、植物乳酸杆菌+布氏乳酸杆菌处理组(LPB)、复合酶制剂+果胶酶+漆酶+植物乳酸杆菌(CLP)、复合酶制剂+果胶酶+漆酶+植物乳酸杆菌+布氏乳酸杆菌处理组(CLPB),以水稻秸秆为研究对象,采用真空聚乙烯袋袋装发酵,贮藏45 d后取样,利用实验室化学分析和半体内法(in situ)对水稻秸秆青贮饲料的营养成分含量、发酵品质及瘤胃降解率进行测定分析.结果表明:(1)与对照组相比,酶制剂处理组(C、PL和CL)pH、乙酸含量、氨态氮/总氮、DM、ADF级纤维素含量显著降低(P<0.05),其DM、NDF、ADF和纤维素瘤胃有效降解率显著升高(P<0.05).(2)与对照组相比,菌制剂处理组(LP、LB和LPB)pH、氨态氮/总氮、NDF、ADF及纤维素含量显著降低(P<0.05),乙酸及DM、纤维素、CP瘤胃有效降解率显著提高(P<0.05).(3)与酶制剂、菌制剂及对照组组相比,复合酶菌制剂处理组(CLP和CLPB)pH和纤维素含量最低,乳酸含量及DM保存量最高,NDF、纤维素及CP的瘤胃有效降解率最高.综上所述,复合酶菌制剂组合添加能更好的改善水稻秸秆青贮饲料的发酵品质,提高其主要营养物质的瘤胃降解率.

本试验以酶制剂、酶-菌复合制剂对玉米秸秆进行生物发酵处理,分析其对玉米秸秆发酵品质、营养成分和纤维微观结构的影响,旨在探索通过打破纤维微观结构提高玉米秸秆利用率的作用机制.试验设置秸秆原料组(CS组)、青贮对照组(CK组)、复合酶制剂组(CPL组)、复合酶-单活菌组(CPLP组)、复合酶-双活菌组(CPLB组).使用真空包装机抽空玉米秸秆青贮袋中的气体,室温发酵45 d后,分析各组青贮玉米秸秆的营养成分和发酵品质;采用苯酚硫酸法+4,4'二羧酸-2,2'-喹啉(BCA)法、傅里叶转换红外光谱(FTIR)、X-射线衍射和伊红美兰法分析各组玉米秸秆纤维微观结构.结果表明:1)与CK组相比,CPL组的pH、氨态氮/总氮(NH3-N/TN)和乳酸/乙酸显著降低(P＜0.05),乳酸、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)、纤维素、半纤维素含量无显著差异(P＞0.05);CPLB组的乳酸含量显著增加(P＜0.05);CPLP和CPLB组的pH、NH3-N/TN、乳酸/乙酸以及NDF、ADF、纤维素、半纤维素含量均显著降低(P＜0.05).2)与CK组相比,CPL组的三级结构结晶度显著升高(P＜0.05),一级结构聚合度和四级结构比表面积无显著差异(P＞0.05),二级结构氢键作用力无明显变化;CPLP和CPLB组的一级结构聚合度显著降低(P＜0.05),四级结构比表面积显著增高(P＜0.05),二级结构氢键作用力减弱,三级结构结晶度无显著差异(P＞0.05).综上,复合酶-单活菌和复合酶-双活菌显著改善了玉米秸秆的化学组成,通过降低玉米秸秆纤维素的一级结构聚合度和三级结构中纤维素非结晶区,减弱二级结构分子间氢键作用力,增加四级结构比表面积,有效地破解了玉米秸秆细胞壁的微观结构,从而提高了秸秆的利用率.

This experiment was conducted to investigate the effects of effects of corn straw silage ensilaged u-sing different methods on slaughter performance, tissue and organ development and serum biochemical indices of mutton sheep. Eighty Dorper×small-tailed Han crossbred F1male lambs with initial body weight of(24.00± 2.42)kg were randomly divided into four groups with five replicates in each group and four lambs per repli-cate. Lambs in different groups were fed dried corn straw(blank control group,BC group),corn straw silage without additive(group Ⅰ), corn straw silage with enzyme-bacteria preparation(group Ⅱ)and Chinese wildrye(Chinese wildrye control group,CC group)as roughage,respectively. The experiment consisted of an 8-day of pre-trial period and a 60-day trial period. The results showed as follows: 1)dry matter intake, live weight before slaughter(LWBS), carcass weight of group Ⅰ and group Ⅱ were significantly higher than those of BC group(P<0.05),and feed/gain was significantly lower than that of BC group(P<0.05);dress-ing percentage of group Ⅱ was significantly higher than that of BC group(P<0.05), feed/gain was signifi-cantly lower than that of group Ⅰ(P<0.05); no significant differences were found in carcass weight and dressing percentage among groupⅠ,groupⅡand CC group. 2)Except liver and rumen weight of groupⅠ, group Ⅱand CC group were significantly higher than those of BC group(P<0.05),no significant differences were found in other tissue and organ weight, as well as their percentage of LWBS(P>0.05). 3)No signifi-cant differences were found in serum biochemical indices among groups(P>0.05). In conclusion,feeding val-ue of corn straw silage was improved after enzyme-bacteria preparation treatment,which has the same effects in promoting growth, tissue and organ development of mutton sheep compared with Chinese wildrye.

In order to find the way to effectively utilize wheat straw,the effect of bacteria and enzyme treatments of wheat straw on growth performance and slaughter performance were studied.80 Dorper×Small-tailed Han crossbred male lambs with initial body weight of (24.00±2.42) kg were randomly divided into four groups with five replicates per group and four lambs per replicete, which were control group (dry wheat straw),treatment group Ⅰ (wheat straw with bacteria and enzyme compound preparations),treatment group Ⅱ (dry wheat straw with enzyme preparations),and Chinese wildrye group (Chinese wildrye).The experiment lasted for 60 d with 8 d of adaptation period.The results showed that the net gain and average daily gain of treatment groups Ⅰ,Ⅱ and Chinese wildrye group were significantly higher than those in control group (P<0.05),and F/G were significantly lower than control group (P<0.05),but those in the three groups were not significantly difference (P>0.05);There were no significant differences of slaughter performance among different groups (P>0.05).Compared with control group,the liver weight in the treatment groups Ⅰ,Ⅱ and Chinese wildrye group were increased 10.74% (P>0.05),13.79% (P<0.05),8.52% (P>0.05), and the percentages of liver weight to live weight before slaughter were significantly higher than that in control group (P<0.05).The other indexes of issues and internal organ (rumen,reticulum,omasum,abomasum,small intestine,large intestine,lung,kidney,head,feet and skin+wool) showed no significant difference (P>0.05).The growth performance of sheep were significantly increased by wheat straw with bacteria and enzyme treating,while the slaughter performance and development of tissues and organs were not significantly affected.The nutrient value of wheat straw with biological treatment was close to Chinese wildrye.

本文旨在研究菌、酶混合制剂和复合酶制剂处理的水稻秸秆,对肉用绵羊营养物质表观消化率与血清生化指标的影响,进而探索对水稻秸秆有效的生物处理方法.采用单因素试验设计,选取体重为(24±2.42)kg的杜泊×小尾寒羊杂交F1代公羔羊80只,随机分为4个处理,每个处理5个重复,每个重复4只.对照组饲喂干水稻秸秆,处理组Ⅰ饲喂添加菌、酶复合青贮制剂水稻秸秆,处理组Ⅱ饲喂添加酶制剂水稻秸秆,处理组Ⅲ饲喂干羊草,预饲期8 d,正式期为60 d.结果表明:处理组Ⅰ试验羊DM、OM、NDF、ADF消化率较对照组分别提高38.40%、22.02%、50.45%、91.97%(P<0.05),其他指标与羊草组差异不显著(P>0.05);处理组Ⅱ试验羊DM、NDF、ADF消化率较对照组分别提高32.02%、42.24%、100.12%(P<0.05),其他指标均与羊草组差异不显著(P>0.05);处理组Ⅰ、Ⅱ各项指标之间差异不显著(P>0.05).试验羊血清生化指标各组间差异不显著(P>0.05).综上,合理的菌酶配伍或酶制剂的合理组合均有利于促进营养物质的消化利用,效果达到或超过羊草水平.

In order to achieve the high-efficiency degradation of crop straw and improve its nutritional value, high efficient degrading enzymes for silage fermentation were used to investigate their effects of microstructure of rice straw silage. Silage control ( S group) , compound enzyme preparation treated ( C group) , pectinase+laccase treated ( PL group) , compound enzyme preparation+pectinase+laccase treated ( CPL group) and raw material ( M group) were used and samples were packaged by vacuum packager in polyethylene bags. After storing at room temperature for 45 d, changes of the silage quality and nutrients content were analyzed using la-boratory testing methods, and changes of microstructure were analyzed using phehol-suffufic acid colorimetry, bicinchoninic acid disodium salt ( BCA) method, fourier transform infared spectroscopy ( FTIR) , X-ray dif-fraction analysis and eosin-methylene blue method. The results showed as follows: 1 ) compared with the S group, the lactic acid ( LA) content in PL, C and CPL groups was significantly increased ( P<0.05) , the pH, ratio of ammonia nitrogen to total nitrogen and content of acetic acid and cellulose were significantly decreased (P<0.05); the crude protein (CP) content in C and CPL groups was significantly decreased (P<0.05). 2) Compared with the S group, the polymerization degree of rice straw silage in PL group was significantly de-creased (P<0.05), which was lowered by 30.26%, the intermolecular hydrogen bond binding force was fa-ded, and specific surface area and crystallinity did not change (P>0.05); the polymerization degree of rice straw silage in C group was significantly decreased (P<0.05), which was lowered by 27.11%, the intermo-lecular hydrogen bond binding force was faded, and specific surface area and crystallinity did not change ( P>0.05); the polymerization degree of rice straw silage in CPL group was significantly decreased (P<0.05), which was lowered by 56.32%, the intermolecular hydrogen bond binding force was faded, and specific sur-face area and crystallinity trend increased ( P>0.05) . In conclusion, CPL group has the best effect, it can ef-fectively break the lignin-cellulose-hemicellulose composite structure and cellulose degraded into available sug-ar, improve the nutrient content of rice straw silage fodder, reduce the degree of polymerization and the crys-tallinity, increase the specific surface area, so as to improve the digestibility and utilization of the straw.

The ruminal dry matter digestibility of corn stalks treated with different biological agents was evaluated by in vitro gas production and in situ methods.The objective of the present study was conducted to determine the the best results of biological agents and effective evaluation method.Treatments were corn stalks (CON),corn stalks silage(CS),composite enzyme(CPL),composite enzyme+Lactonacil lus plantarum(CPLP),composite enzyme+ Lactonacillus plantarum+ Lactonacillus Buchneiri(CPLB).In vitro gas production(GP),in vitro dry matter digestibility(IVDMD) and in situ dry matter degradability (DMD) of corn stalks were measured by in vitro method and in situ method,respectively,and the correlation analysis was carried out.The results showed that:① The GP72h and the theoretical maximum gas production of CPLP were the highest,and the GP72h of CPLP was 52.33 ml,which was significantly higher than CON,CS and CPL group (P＜0.05).There was no significant difference between CPLP group and CPLB group (P＞0.05),the 72 h cumulative net gas production of corn stalk was:CPLP＞ CPLB＞CPL＞CS＞CON;② The degradation rate of DM72h and the effective degradation of CPLB were the highest,and the degradation rate of CPLB was higher than CON,CS and CPL 41.80％,15.26％,23.69％,respectively;(The correlational analysis were conducted that the correlation coeffiencients between DMD24 h and GP24h,IVDMD24h were 0.827 and 0.751,respectively.The correlation coeffiencients between DMD24h and GP48h,IVDMD48 h were 0.847 and 0.745,respectively.The correlation coeffiencients between DMD48 h and GP24 h,IVDMD24 h were 0.804 and 0.828,respectively.The correlation coeffiencients between DMD48h and GP48 h,IVDMD48 h were 0.842 and 0.830,respectively.In conclusion,the in vitro gas production and in situ methods showed that the feed value of CPLP group and CPLB group was significantly better than CPL group,CS group and CON group.There were significant relationships between in vitro gas production and in situ methods indicating that the in vitro gas production method could be used to determine the ruminal dry matter degradation of corn stalks.

Crop straw is an important source of roughages for ruminants,but its complex cell wall structure hinders its effective degradation in the rumen.The main ways to improve utilization rate of crop straw are physical,chemical and biological treatment.Bio-fermented straw as roughage is widely used in the ruminant diet and has an irreplaceable advantage,which is highly valued by cattle and sheep farmers.Systematical and objective evaluation of the feeding value of bio-fermented straw is of great significance for its use in the diet.This paper mainly summarized the concept,application and evaluation methods of bio-fermented crop straw.

In order to find the way to effectively utilize biological enzymes, the effects of different biological treatments of rice straw on growth performance, slaughter performance and organ development of mutton sheep were investigated in this experiment. Eighty "Dorper×small-tailed Han" F1 crossbred male lambs with the ini-tial weight of (24.00±2.42) kg were randomly divided into four groups with five replicates in each group and four lambs per replicate. Lambs in blank control group were fed a rice straw diet, lambs in group Ⅰ were fed the rice straw diet which treated with bacterial and enzyme compound silage preparation, lambs in group Ⅱwere fed the rice straw diet which treated with compound enzyme preparation, and lambs in Leymus chinensis group wwere fed a Leymus chinensis diet. There was a adaptation period of 8 days followed by an experimental period of 60 days. The results showed as follows: the average daily gain and dry matter intake of sheep in group Ⅰ, group Ⅱ and Leymus chinensis group were significantly higher than those in blank control group (P<0.05), and the ratio of feed to gain was significantly lower than that in blank control group (P<0.05), but those in group Ⅰ, groupⅡ and Leymus chinensis group were not significantly different ( P>0.05) . There was no significant difference in dressing percentage of sheep among all groups ( P>0.05) . The weight of head, feet, skin+wool, lungs, kidneys, reticulum, omasum, abomasum, small intestine and large intestine and their weight percentage of live weight before slaughter of sheep had no significant difference among all groups ( P>0.05) , the liver and rumen weights of sheep in group Ⅰ, group Ⅱ and Leymus chinensis group was signifi-cantly higher than those in blank control group ( P<0.05) . In conclusion, the rice straw is improved by bacteri-al and enzyme compound silage preparation, and the growth performance, slaughter performance and organ de-velopment of mutton sheep are close to the feeding effect of Leymus chinensis.

Corn straw, wheat straw and rice straw are the most abundant agricultural by-products and also the potential roughage resources for ruminants. However, due to the low digestibility, they are hard to be utilized,therefore, how to improve their feeding values in agriculture and animal husbandry is a hot topic home and abroad.This article mainly summarized the research advance in the biodegradation technigue of wheat straw and rice straw with an aim to provide references for a better utilization.

A study has been undertaken to investigate the effects of probiotics on the fermentation quality,nu-trition composition and in situ ruminal degradability of corn stalk silage.Green corn stalk without ears (dry matter=42%-44%)was chopped to 2 cm lengths and then 1 kg of chopped corn stalk was packed with addi-tives (zymin,fungus-preparation,and a mixture of the zymin and fungus-preparation)in polyethylene bags (24 cm×40 cm)using a vacuum packager.After 45 days of fermentation at room temperature,the corn stalk si-lage’s fermentation quality,nutrition composition and in situ ruminal degradability were analyzed using labora-tory chemical methods and in situ technology.The results showed that,compared to the control,the pH value and ammonia nitrogen (NH 3-N)content of the two lactobacillus (LAB1 and LAB2 )treatments decreased (P <0.05),whereas contents of lactate acid (LA),organic matter (OM),water soluble carbohydrates (WSC),and the in situ ruminal degradability of DM,OM and crude protein (CP)increased significantly (P <0.05).The addition of lactobacillus increased WSC content (P <0.05)compared with the control and cellulase treatments. Compared with the control,the pH value,NH 3-N content,neutral detergent fiber (NDF),acid detergent fiber (ADF),and cellulose content of the cellulase treatments (CE1 and CE2 )significantly decreased (P <0.05 ). Furthermore,the acid detergent lignin (ADL)content had a decreasing trend (P >0.05).The mixture of cel-lulase and lactobacillus treatments (MCL1 and MCL2 )had the lowest pH value and the highest in situ degrada-tion of NDF and cellulose compared with other treatments (P <0.05).In addition,in situ degradation of ADL increased but did not reach significance (P >0.05).Compared with the control,the NDF,ADF and cellulose contents of the cellulase and lactobacillus mixture treatments significantly decreased (P <0.05).In conclusion, the application of cellulase and lactobacillus mixtures to the fermentation of corn stalk contributed to the break-down of lignin-cellulose-hemicellulose composite structures and the improvement of fermentation quality, which consequently resulted into high nutrient digestibility and utilization efficiency.The MCL2 treatment had the best effect in this regard.

The basic composition of straw could be revealed from the molecular level by the microstructure of cellu-lose.It could also explain the effect of crack of plant cell wall and provide effective evidence for improving straw utiliza-tion.This paper summarized the quarternary structure of cellulose and related methods to break down this structure ,which provided theoretical basis and guidance for the application of straw feed.

To improve the silage quality and reduce the silage additive cost, the present experiment was designed to evaluate the potential of applying the fermented juice of epiphytic lactic acid bacteria (FJLB) as an additive in alfalfa silage. The effects of FJLB on the fermentation quality, carbohydrate and protein fractions, and aerobic stability of alfalfa silage wilted under five different conditions were investigated and compared with commercial lactic acid bacteria (CLAB) and the control. The FJLB application decreased the pH value, the volatile fatty acids and non-protein nitrogen content, and the loss of sugar by 9.9%, 22.9%, 19.6% and 9.6%, respectively; it increased the lactic acid concentration by 29.5% and the aerobic stability by 17 h in comparison to the control. The FJLB application also decreased the pH value (4.44 vs. 4.66) and volatile fatty acid content (38.32 vs. 44.82) and increased the lactic acid concentration (68.99 vs. 63.29) in comparison to the CLAB-treated silage. However, the FJLB treatment had lower aerobic stability (254 h vs. 274 h) than the CLAB treatment. The FJLB application improved silage quality in comparison to the control; in addition, its effect as a fermentation stimulant may be comparable to or even better than CLAB.

The objective of the present study was to investigate the effects of ensiling process of corn stalk si-lage on its sensory indicators, fermentation quality, nutrition composition and bacteria composition and abun-dance in phylum, class, order, family and genus.Green and dough stage corn stalk without ear was chopped to 1 to 2 cm with water content of 65%to 70%.Each three samples were collected and packaged by vacuum packager in polyethylene bags before and after ensiling process.After being stored at room temperature for 45 days, changes of the silage quality and bacteria composition were analyzed using laboratory testing methods and MiSeq sequencing technology.The results showed as follows:1) the corn silage was yellow-green and had the good texture and smell after ensiling 45 days.The pH was rapidly increased ( P<0.05) , the lactic acid content was significantly increased ( P<0.05) , while the content of neutral detergent fiber ( NDF) and acid detergent fiber ( ADF) had the downward trend ( P>0.05) .2) After ensiling of corn silage, the numbers of Proteobac-teria plylum, Gammaproteobacteria class, Enterobacteriales order, Enterobacteriaceae family and Weissella ge-nus were significantly decreased ( P<0.05) , while the numbers of Firmicutes phylum, Bacilli class, Lactoba-cillales order, Lactobacillaceae family, and Pediococcus and Lactobacillus genus were significantly increased ( P<0.05) .In conclusion, ensiling process can improve the sensory indicators, fermentation quality, nutrition composition with effectively reducing the amount of harmful bacteria and increasing the number of beneficial bacteria, which can reduce the potential risk to animal health pathogens exist.Combing laboratory testing meth-ods and MiSeq sequencing technology can provide the information of silage quality and the composition and a-bundance of bacteria, which can provide the basis for the regulation of the fermentation process.

The pH optimum and thermostability of both exopeptidases and endopeptidases were investigated in this study to elucidate the possible role of plant proteases in proteolysis during ensiling of alfalfa herbage. Proteolytic activities of 4 classes of endopeptidases (i.e., serine, metallo, aspartic, and cysteine peptidase) and 5 classes of exopeptidases (i.e., aminopeptidase, carboxypeptidase, dipeptidase, dipeptidyl-peptidase, and tripeptidyl-peptidase) were examined within pH values of 3 to 9, and within temperatures from 20 to 90°C. Serine and metalloproteases, the principal endopeptidases that hydrolyzed most of the protein to nonprotein nitrogen in alfalfa silage, had optimum activities at pH 4. Among the major exopeptidases contributing protein degradation in ensiled alfalfa, dipeptidase and tripeptidyl-peptidase had stable activities between pH 4 and 6, and carboxypeptidase activity was optimal at pH 5. The optimum temperature for most peptidase activities was 40°C. Proteolytic activities of both endo- and exopeptidases increased with the elevation of incubating temperature from 20 to 40°C. The pH value in well-preserved alfalfa silage is often above 4.0, and the temperatures in the ensiled mass range from 25 to 40°C. Therefore, high proteolytic activities between pH 4 and 6 and the temperature range of ensiled alfalfa suggest that plant peptidases play a role in hydrolyzing protein during prolonged storage.

The effect of epiphytic microorganisms and exogenous Lactic Acid Bacteria (LAB) on the formation of Non-Protein Nitrogen (NPN) components during the ensiling process was investigated. All silages were prepared in mini-silos of 100 mL polypropylene centrifuge tubes and kept in an incubator at 30 degrees C and tubes of each treatment were opened after 1, 3, 7, 14 and 35 days of ensiling. Treatments included three variations: nothing added (control); epiphytic microorganisms killed (treated with Ultraviolet (UV) rays) and xogenous lactic acid bacteria (inoculants of lactic acid bacteria after treatment with UV rays) added.

Lawn grasses play an increasing role in urban greening and environment conservation.Shade tolerance is a particularly serious problem for lawn grasses resulting from tall city buildings.Tall fescue and Kentucky bluegrass are two main cool-season lawn grasses.The technology of improving shade tolerance of lawn grasses are discussed in this paper.Both lawn grasses under 57% shade stress are treated using ABA,sucrose and silicon.Each treatment includes four difference concentrations(ABA: 0,0.02,0.06,0.10 mmol·L-1,sucrose: 0,600,800,1000 mg·L-1,silicon: 0,0.50,1.00,1.50 mmol·L-1).Results indicate that ABA is not suitable for enhancing shade tolerance of either lawn grasses,but both sucrose and silicon can promote shade tolerance for both lawn grasses.The best concentration of sucrose is 800 mg·L-1 for tall fescue and 600 mg·L-1 for Kentucky bluegrass.The best concentration of silicon is 0.50 mmol·L-1 for tall fescue and 1.50 mmol·L-1 for Kentucky bluegrass.

The experiment was conducted to investigate the exopeptidase classes in alfalfa (Medicago sativa L.) leaves, and to determine their contribution to the formation of nonprotein nitrogen (NPN) components during ensiling. Six classes of inhibitors that included bestatin (aminopeptidase inhibitor), potato carboxypeptidase inhibitor (PCI, carboxypeptidase inhibitor), 1,10-phenanthroline (dipeptidase inhibitor), diprotin A (dipeptidyl-peptidase inhibitor), butabindide (tripeptidyl-peptidase inhibitor), and dipeptide Phe-Arg (peptidyl-dipeptidase inhibitor) were used. To determine the contribution of each exopeptidase to the formation of NPN products, aqueous extracts of fresh alfalfa were fermented to imitate the proteolytic process of ensiled alfalfa and to ensure that each class of exopeptidase inhibitor would have immediate contact with the proteases in the alfalfa extract. Five classes of exopeptidases; namely, aminopeptidase, carboxypeptidase, dipeptidase, dipeptidyl-peptidase, and tripeptidyl-peptidase, were shown to be present in alfalfa leaves, each playing a different role in alfalfa protein degradation. Aminopeptidase, carboxypeptidase, and dipeptidase were the main exopeptidases contributing to the formation of NH(3)-N. Among the 5 exopeptidases, tripeptidyl-peptidase appeared to be the principal exopeptidase in hydrolyzing forage protein into peptides, whereas carboxypeptidase and dipeptidase appeared to be more important in contributing to the formation of amino acid-N. Dipeptidyl-peptidase and tripeptidyl-peptidase did not play a role in the formation of NH(3)-N or amino acid-N. Dipeptidase, carboxypeptidase, and tripeptidyl-peptidase were the principal exopeptidases for hydrolyzing forage protein into NPN during ensilage, and treatment with a mixture of the 5 inhibitors reduced the total NPN concentration in the fermented alfalfa extract to about 45% of that in the control after 21 d of fermentation.

为探讨金属肽酶在苜蓿青贮过程中对蛋白的降解作用，以苜蓿（Medicago stativa L.）绿汁发酵液模拟青贮发酵过程，添加金属肽酶抑制剂后，测定发酵后第0.5、1、1.5、2、2.5、3、4、5、7和14天时绿汁发酵液的蛋白组分。结果表明，在苜蓿发酵液发酵过程中添加金属肽酶抑制剂能够降低pH值、非蛋白氮、游离氨基酸和氨态氮含量，增加乳酸含量；发酵第14天时，抑制剂处理组非蛋白氮、游离氨基酸和氨态氮质量分数为483.98 g/kg TN，256.98 g/kg TN和26.11 g/kg TN，与对照组相比分别降低28.92%，38.59%和67.08%。金属肽酶对苜蓿发酵液蛋白降解起着一定的作用；添加金属肽酶抑制剂能够提高发酵液发酵品质。

The effects of different additives, including lactic acid bacteria inoculants, acremonium cellulase and mixtures of lactic acid bacteria inoculants and acremonium cellulase on changes of nutritive components and in vitro digestibility of Ceratoides arborescens during ensiling were investigated. The silages of each treatment were prepared in plastic film bags, kept in an incubator at 30 degrees C and bags were opened after 1, 3, 5, 10, 30 and 45 days at room temperature. The results show that addition of additives and ensiling time did not affect acid detergent lignin content during ensiling (P>0.05). With ensiling time, pH value decreased (P<0.05), whereas the concentrations of lactic acids, acetic acid, propionic acid, butyric acid and ammonia nitrogen increased (P<0.05). At 45 days of fermentation, the silages treated with the mixture of 50 mg lactic acid bacteria and 200 mg acremonium cellulase showed the lowest (P<0.05) pH value, neutral detergent fiber and acid detergent fiber contents, and the highest (P<0.05) in vitro digestibility of neutral detergent fiber and acid detergent fiber, water soluble carbohydrate and lactic acids concentrations compared to other treatments. Lactic acid bacteria can improve C. arborescens silage fermentation quality; cellulase had a positive effect on in vitro digestible of neutral detergent fiber. There was favorable interaction between the addition of lactic acid bacteria and cellulase on the silage fermentation quality and chemical composition of C. arborescens.