枯草芽孢杆菌在发酵饲料中的应用研究进展

枯草芽孢杆菌是一种益生菌，在粗饲料中添加枯草芽孢杆菌进行发酵处理得到的饲料为发酵饲料。本文对枯草芽孢杆菌发酵饲料，几种发酵饲料原料和发酵饲料工艺，以及固态发酵、液体发酵和枯草芽孢杆菌发酵饲料在不同领域内的应用进行综述，并对枯草芽孢杆菌发酵饲料的应用前景进行展望。 [关键词] 枯草芽孢杆菌|发酵饲料|研究进展     

Effects of Compound Probiotics on Fermentation Quality of Total Mixed Ration

The study was aimed to investigate the influences of compound microbial on the quality of fermented TMR. There were 3 treatments:Control group (basal TMR),experimental group 1 (TMR with 0.5% compound microbial supplement (Lactobacillus, Bacillus subtilis, Bacillus cereus and yeast)), experimental group 2 (TMR with 0.5% supplement (Lactobacillus, Bacillus subtilis, Bacillus cereus and cellulolytic bacteria)), with 6 replicates in each group and 2 tankers per replicate. The experiment lasted 30 d. Water content of the materials in all the tankers were controlled at 50% and sealed airtightly for 30 d. Samples were cllected at 0,3,5,7,15 and 30 d. Mycotoxins, pH, ammonium nitrogen, aerobic stability and nutrient content were determined and analyzed. The results showed as follow:①During 0~30 d, the content of mycotoxins showed an upward trend in all treatments. On the 30th day, aflatoxin B₁ content and ochratoxin-A content in the control group were exceeded than the national standard. However, three kinds of mycotoxins were not exceeded in experimental groups 1 and 2 during the 30 d fermentation.② Aerobic stability and storage time were positively correlated, the aerobic stability of experimental group 1 was better than other treatments. ③ With the last of storage time, pH in 3 groups showed downward trend and ammonium nitrogen content showed an upward trend. pH value and ammonium nitrogen content in experimental group 1 was significantly lower than the control group during 7-30 d (P<0.05). ④ On the 30th day, DM content in control group was significantly lower than the other treatments (P<0.05);During 7-30 d, compared with the control group, CP content in experimental groups 1 and 2 were significantly decreased (P<0.05). The contents of NDF and ADF were negatively correlated with storage time, moreover, During 7~30 d, the levels of NDF and ADF in two experimental groups with compound microbial significantly decreased (P<0.05). In conclusion, the compound microbial supplement could prolong the storage time of TMR and strengthen its aerobic stability. In addition, the degradation of feed nutrient was limited. The compound probiotics, which was composed of Lactobacillus, Bacillus subtilis, Bacillus cereus and yeast was more effective.     

Effect of ensiling process of total mixed ration on fermentation profile,nutrient loss and in situ ruminal degradation characteristics of diet

This experiment aimed to determine the changes in chemical composition, fermentation profile, in situ disappearance characteristics, and nutrient losses of ensiled total mixed ration (TMR) containing steam‐flaked corn or brown rice (BR) during storage. TMRs for dairy cows, containing either steam‐flaked corn or BR at 31.9% with 15.2% rye silage, 40.5% alfalfa silage, 5.0% beet pulp and 7.0% soybean meal, were prepared (dry matter (DM) basis). Each TMR was placed in a plastic drum silo, stored at 23°C in an air‐conditioned room and sampled 0, 7, 14, 30, 90 and 210 days after preparation. In both grain sources, the fermentation products increased, while DM and starch storage losses increased and starch content greatly decreased during storage. The rapidly degradable fraction and effective ruminal degradability of DM, crude protein and starch increased during storage. These changes of dietary characteristics were large during 30 days of storage, but small after 90 days of storage. Replacing corn with BR led to increased fermentation products, starch loss and effective ruminal degradability of the ensiled TMR. These results indicate that the ensiling process of TMR changes the dietary characteristics and replacing corn with BR in TMR had a large impact on these dietary characteristics.     

添加复合益生菌对全混合日粮发酵品质的影响

本试验旨在研究添加复合益生菌对全混合日粮（total mixed ration,TMR）发酵品质的影响。试验设3组：对照组,TMR;试验1组,TMR+0.5%复合益生菌1（乳酸菌、枯草芽孢杆菌、蜡样芽孢杆菌和酵母菌复合物）;试验2组,TMR+0.5%复合益生菌2（乳酸菌、枯草芽孢杆菌、蜡样芽孢杆菌和纤维分解菌复合物）。每组6个重复,每个重复2个贮存罐,调整TMR含水量为50%,密闭发酵,试验期30 d。分别在发酵第0、3、5、7、15和30天测定TMR中霉菌毒素、pH、铵态氮、有氧稳定性及养分含量。结果表明：①不同处理TMR中霉菌毒素含量随发酵时间延长而呈上升趋势,发酵第30天时,对照组黄曲霉毒素B₁和赭曲霉毒素A含量超过国家标准。整个试验期内,试验1、2组TMR各时间点3种霉菌毒素含量均未超标;②各组TMR有氧稳定性随发酵时间延长而升高,在发酵第3、5、7、15、30天,试验1组有氧稳定性优于对照组和试验2组;③随着贮存时间延长,各试验组pH呈下降趋势,各处理TMR的铵态氮含量呈上升趋势。在发酵第7~30天,试验1组pH、铵态氮含量显著低于对照组（P<0.05）;④在发酵第30天,两试验组干物质含量显著高于对照组（P<0.05）;发酵第7~30天,试验1、2组TMR的CP含量均显著高于对照组（P<0.05）;各试验组的NDF和ADF含量随发酵时间延长而呈降低趋势,发酵第7~30天时,试验组NDF和ADF含量均低于对照组（P<0.05）。综上所述,添加复合益生菌发酵有利于延长TMR贮存时间,强化全混合日粮有氧稳定性并能在一定程度上降低营养损失。由乳酸菌、枯草芽孢杆菌、蜡样芽孢杆菌和酵母菌组成的复合益生菌处理效果最佳。     

Effect of Fermented Corn Stalks on Growth Performance and the Growth Promotion Mechanism in Otter Rabbit

This experiment was conducted to research the growth promoting effects of fermented corn stalks with compound bacteria on otter rabbit. The daily feed of otter rabbit was based on fermented corn stalks (roughage ration composed mostly of fermented corn stalks). The growth performance, intestinal tract bacteria and the digestive enzyme activities of otter rabbit were studied. A total of 150 health otter rabbits, 9 weeks old, weighted about (1.90±0.14) kg, were allotted to 2 groups (control group and experimental group) for 10 days preliminary trial period and 30 days trial period. The results were as follows:Compared with control group, the average daily gain (ADG) increased by 14.60% (P<0.05) and F/G decreased by 10.50% (P<0.05) of the experimental group; In intestinal tract of otter rabbit, the number of E.coli were reduced by 46.13% (P<0.01), the number of Lactobacillus, Bifidobacteria and Bacillus increased by 30.64% (P<0.05), 29.27% (P>0.05) and 39.23% (P<0.01),respectively; The activities of protease, amylase, cellulose enzyme and glucanase were increased by 23.20%(P<0.05), 32.96% (P<0.05), 12.63% (P<0.01) and 21.09% (P<0.05), respectively. In conclusion, the fermented corn stalks could promote the growth and improve the intestinal tract ecological environment of the otter rabbit. The results established the theoretical foundation for fermented corn stalks feeding on otter rabbit.     

发酵玉米秸秆对獭兔生长性能的影响及其促生长机理的研究

试验旨在研究经复合菌剂发酵后的玉米秸秆粗饲料对獭兔的促生长效果。用以发酵玉米秸秆为主要粗饲料配制的日粮饲喂獭兔,从试兔生长性能、肠道菌群结构、消化酶活力的变化来揭示发酵玉米秸秆对獭兔生长的影响。选择体况良好,9周龄、体重（1.90±0.14） kg獭兔150只,将其分为对照组（饲喂常规基础日粮）和试验组（发酵玉米秸秆为主要粗饲料的日粮）,预试期10 d,正试期30 d。结果显示,与对照组相比,试验组獭兔平均日增重（ADG）提高了14.60%（P<0.05）,料重比（F/G）降低了10.50%（P<0.05）;盲肠内容物中大肠杆菌数量降低了46.13%（P<0.01）,乳酸菌、双歧杆菌、芽孢杆菌数量分别提高了30.64%（P<0.05）、29.27%（P>0.05）和39.23%（P<0.01）;盲肠中蛋白酶、淀粉酶、纤维素酶、葡聚糖酶活力较对照组分别提高了23.20%（P<0.05）、32.96%（P<0.05）和12.63%（P<0.01）、21.09%（P<0.05）。综合以上结果,发酵玉米秸秆可促进獭兔生长,改善肠道微生态环境。试验结果可为发酵玉米秸秆在獭兔中的应用提供理论基础。     

膨化秸秆微生物发酵饲料对杜寒杂交肉羊瘤胃发酵的影响

[目的]以粗饲料作为唯一变量,研究膨化秸秆微生物发酵饲料对杜寒杂交肉羊瘤胃发酵的影响.[方法]选择81只3月龄、体重为(23±1.0)kg的杜寒杂交羔羊,随机分为对照组(70％精料+30％干秸秆)、试验Ⅰ组(70％精料+30％膨化秸秆微生物发酵饲料)和试验Ⅱ组(70％精料+30％膨化秸秆微生物发酵饲料,再添加占日粮总蛋...     

不同精粗饲料比例对压缩型TMR颗粒饲料成型品质影响的研究

为研究不同精粗饲料比例对压缩型TMR颗粒饲料成型品质的影响,试验设计3个不同水平的精粗饲料比5∶5、4∶6、3∶7,粗饲料选用玉米秸秆和苜蓿干草,两者比例分别为1∶2、1∶1、2∶1,采用双因子多水平试验设计,按照压缩TMR颗粒饲料生产工艺流程生产压缩型TMR颗粒饲料,比较不同水平下,精粗比对压缩型TMR颗粒饲料感官性质、含粉率、粉化率、硬度、容重、密度、长度和直径等物理指标的影响。试验结果表明：随着饲料中精饲料比例的降低,粗饲料比例的增加,压缩型TMR颗粒饲料的感官品质下降,颗粒含粉率和粉化率显著增加（P < 0.05）,硬度显著降低（P < 0.05）,容重和密度显著降低（P < 0.05）,颗粒长度显著增加（P < 0.05）,对颗粒直径没有显著影响（P > 0.05）|不同粗饲料组成玉米秸秆与苜蓿干草比对饲料成型品质影响不显著（P > 0.05）|不同精粗比与粗饲料组成的交互作用对颗粒含容重和密度有显著影响（P < 0.05）。 [关键词] 压缩型TMR颗粒饲料|感官性质|物理指标     

裹包青贮技术在产奶牛用全混合日粮贮存中的应用研究

为使中小奶牛养殖场和奶牛养殖小区的奶牛养殖户用上营养平衡的全混合日粮（TMR）,研究利用拉伸膜包裹TMR饲料成品后贮存的效果。该研究对高产奶牛和中产奶牛用两种TMR进行裹包贮存,并于0d、3d、7d、15d、30d和60d分别取样进行裹包贮存外观评定、感官评定及营养物质含量和发酵指标的测定。试验结果表明,两种TMR裹包贮存后外观质量和感官质量良好;随贮存时间的延长,干物质含量有所降低,而粗蛋白、粗脂肪、粗纤维、粗灰分等营养指标有所增加;随贮存时间的延长裹包TMR的pH值显著降低（P〈0．05）,氨态氮含量显著上升（P〈0．05）。综合外观和感官评定及各项营养指标、发酵指标的变化,TMR裹包贮存技术可以为TMR饲喂技术在中小奶牛养殖场和奶牛养殖小区中应用提供技术支持。     

不同精粗比日粮对雷州山羊体外瘤胃发酵的影响

本试验通过体外发酵法,探讨皇竹草和精料以不同比例配制成的全混合日粮（TMR）对雷州山羊体外瘤胃发酵的影响。试验采用精料与皇竹草按干物质0：100（Ⅰ组）、10：90（Ⅱ组）、20：80（Ⅲ组）、30：70（Ⅳ组）和40：60（V组）比例配制日粮,在体外发酵的第4、8、12、24和48 h取样分析其发酵参数的变化,为皇竹草在雷州山羊TMR中的应用提供参考。结果显示,①随着精粗比的提高,粗蛋白质含量逐渐增高,纤维物质、粗灰分含量逐渐降低,且4、8、24、48 h累积产气量呈现极显著增长（P<0.01）。②随着发酵时间和精料添加比例的增加,瘤胃pH呈下降趋势,同一时间点,Ⅳ、Ⅴ组pH均显著低于Ⅰ、Ⅱ组（P<0.05）;干物质降解率呈上升趋势,同一时间点,Ⅳ、Ⅴ组的降解率均极显著高于Ⅰ、Ⅱ组（P<0.01）;48 h的氨态氮浓度均高于4 h,4、24 h时各组间均无显著差异（P>0.05）。③pH与累积产气量和干物质降解率呈显著或极显著的负相关,累积产气量与干物质降解率呈显著或极显著的正相关（P<0.05;P<0.01）;各个发酵时间pH与干物质、粗灰分、粗纤维、中性洗涤纤维和酸性洗涤纤维呈显著或极显著正相关,与粗蛋白质呈显著或极显著负相关（P<0.05;P<0.01）;累积产气量和干物质降解率与TMR日粮粗蛋白质含量呈显著或极显著正相关,与干物质、粗灰分、粗纤维、中性洗涤纤维和酸性洗涤纤维呈显著或极显著负相关（P<0.05;P<0.01）。综上,在本试验条件下,精料和皇竹草的比例为30：70时,可获得较好的发酵效果,且可节约成本。     

Effects of Diets with Different Concentrate to Forage Ratios on in Vitro Rumen Fermentation of Leizhou Goats

This study was conducted to study the effect of different ratios of concentrate to Pennisetum sinese Roxb in diet on in vitro rumen fermentation in Leizhou goats. In vitro fermentation method was used and diets with different concentrate to Pennisetum sinese Roxb were prepared which the ratio were 0:100 (group Ⅰ),10:90 (group Ⅱ),20:80 (group Ⅲ),30:70 (group Ⅳ) and 40:60 (group Ⅴ),respectively, and the samples were analyzed after fermented for at 4,8,12,24 and 48 h. The results showed that:①With the increase of the concentration to roughage ratios,the crude protein content of TMR diets increased and the fiber material and crude ash contents decreased gradually. With the increase of concentration,the gas production at 4,8,24,48 h were extremely significantly increased (P<0.01).②With the increase of fermentation time and the concentration to roughage ratios,the pH of rumen fluid were decreased,and pH of groups Ⅳ and Ⅴ were significantly lower than groups Ⅰand Ⅱ at the same time (P<0.05).And the dry matter degradation were increased,and that of groups Ⅳ and Ⅴ were extremely significantly higher than groups Ⅰand Ⅱ at the same time (P<0.01). The NH₃-N content at 48 h was higher than that at 4 h and there was no siginificant difference among groups at 4 and 24 h (P>0.05).③The correlation between pH and accumulated gas production, dry matter degradation rate were significantly or extremely significantly negative,that between accumulated gas production and dry matter degradation rate were significantly or extremely significantly positive (P<0.05;P<0.01).The correlation between pH and dry matter, crude ash, crude fiber, neutral detergent fiber and acid detergent fiber were significantly or extremely significantly positive,that with crude protein was significantly or extremely significantly negative (P<0.05;P<0.01).And the correlation between cumulated gas production,dry matter degradation rate and crude protein was significantly or extremely significantly positive,while that with the dry matter,crude ash,crude fiber, neutral detergent fiber and acid detergent fiber were significantly or extremely significantly negative (P<0.05;P<0.01). In summary, under the conditions of this test, the appropriate ratio of concentrate to Pennisetum sinese Roxb was 30:70 in which Leizhou goat could get a better fermentation effect and cost savings.     

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.     

甘草风味发酵乳的研制

[目的]以复原乳为原料,利用甘草提取液、瑞士乳杆菌、嗜热链球菌和保加利亚乳杆菌,发酵制备风味发酵乳。[方法]通过单因素试验,研究甘草液添加量、白糖添加量和发酵时间对试验产品感官品质影响。利用正交试验,设计甘草风味发酵乳的最佳工艺参数。[结果]甘草风味发酵乳的最佳发酵条件：接种量3%,甘草提取液添加量20%,白砂糖添加量6%,42℃发酵6 h。发酵乳风味良好,凝乳状态均匀,有较好的15天贮藏期稳定性,有较好感官品质,保持活菌数在6.5×108 CFU/mL以上。[结论]本文经过试验研制新口味发酵乳,拓宽发酵乳市场,满足消费者需求。     

发酵工艺参数对发酵豆粕营养成分的影响

为探讨发酵豆粕生产的最适条件,本研究测定不同的菌种接种量、发酵温度、水分、发酵时间、辅料等几种因子对豆粕发酵效果的影响。结果显示枯草芽孢杆菌、酿酒酵母菌、乳酸菌的添加比例分别为3‰、2‰、1‰,蛋白酶添加量为2‰,菌种活化时间为0.5 h,发酵的初始水分为38%,温度保持在30~42 ℃时,发酵豆粕的理化指标最优,其中小肽含量可达20%以上,乳酸含量可达3.5%以上,并且质量稳定。     

Effects of enzyme supplementation of a total mixed ration on microbial fermentation in continuous culture, maintained at high and low pH

A dual-flow continuous culture system was used to investigate the effects of pH and addition of an enzyme mixture to a total mixed ration (TMR) on fermentation, nutrient digestion, and microbial protein synthesis. A 4 x 4 Latin square design with a factorial arrangement of treatments was used, with four 9-d periods consisting of 6 d for adaptation and 3 d for measurements. Treatments were as follows: 1) high pH with control TMR, 2) high pH with TMR treated with enzyme, 3) low pH with control TMR, and 4) low pH with TMR treated with enzyme. Ranges of pH were 6.0 to 6.6 and 5.4 to 6.0 for high and low, respectively. Fermenters were fed twice daily a TMR consisting of 30% alfalfa hay, 30% corn silage, and 40% rolled corn (DM basis). The silage was milled fresh and the TMR was fed to the fermenters in fresh form (64% DM). The enzyme mixture was a commercial product of almost exclusive protease activity; it was applied daily to the fresh TMR and stored at 4 degrees C for at least 12 h before feeding. Degradability of OM, NDF, ADF, and cellulose was decreased (P < 0.05) by low pH. Hemicellulose and protein degradation were not affected by pH. Enzyme addition increased (P < 0.01) NDF degradability (by 43% and 25% at high and low pH, respectively), largely as a result of an increase in hemicellulose degradation (by 79% and 51% at high and low pH, respectively). This improvement was supported by an increase (P < 0.05) in the xylanase and cellulase activities in the liquid phase of the fermenter contents. Total VFA were decreased (P < 0.05) by low pH, but were not affected by enzyme addition. Total bacterial numbers were increased (P < 0.03) at low pH and tended (P < 0.13) to increase with enzyme addition. Cellulolytic bacteria in effluent fluid were decreased (P < 0.02) at low pH but were unaffected by enzyme addition. Despite a large increase (P < 0.001) in protease activity, protein degradation was only numerically increased by enzyme addition. Microbial protein synthesis was higher (P < 0.10) at high pH but was not affected by enzyme addition. Methane production, expressed as a proportion of total gases, was decreased (P < 0.001) at low pH but was not affected by enzyme addition. It is concluded that it is possible to adapt the continuous culture system to use fresh feeds instead of dried feeds. Overall, the results indicate that the enzyme product used in this study has a potential to increase fiber degradability without increasing methane production.     

Influence of Process Parameters on Nutritional Components of Fermented Soybean Meal

To study the optimal condition of fermented soybean meal production, several factors were selected to study the effects of different strains inoculation quantity, fermentation temperature, moisture content, fermentation time and accessories on soybean meal fermentation.The results showed that when Bacillus subtilis, Saccharomyces cerevisiae and Lactobacillus addition proportions were 3‰, 2‰, 1‰, respectively, proteinase supplementation was 2‰, strains activation time was 0.5 h, initial moisture content was 38%, fermentation temperature kept at 30 to 42 ℃, physical and chemical indexes of fermented soybean meal were optimal, the contents of small peptide and lactic acid could reach more than 20% and 3.5%, respectively, and at the same time, quality of fermented soybean meal was very stable.     

豆基发酵乳的制备及过程机理分析

以轴流磨工艺所制豆浆、白砂糖、乳糖、葡萄糖、乳酸菌为原料制备豆基发酵乳,工艺设计实验结果表明：豆浆1000mL、白砂糖90g、乳糖10g、葡萄糖2g、乳酸菌0．2g,42℃发酵76h,产品品质佳。该豆基发酵乳产品在4℃、24h冷藏保质期内,活菌数平均值达3．0×10^CFU／g,蛋白质3．6％,脂肪2．5％,酸度90．05。T,pH4．52,大肠菌群79个／mL,脲酶阴性,致病菌未检出,符合国标GB19302-2010《发酵乳》要求。同时,该豆基发酵乳具有新鲜、操作方便、适合商业生产应用等优点,具有广泛的商业前景。     

奶牛饲喂不同精粗料比TMR对排泄粪尿和氮磷的影响

将18头荷斯坦产奶牛随机分为试验6组,每组3头,试验Ⅰ～Ⅵ组奶牛依次饲喂不同精粗料比（精料：粗料）的TMR1（20∶80）、TMR2（30∶70）、TMR3（40∶60）、TMR4（50∶50）、TMR5（60∶40）、TMR6（70∶30）的日粮,探讨不同精粗料比TMR对奶牛粪尿、N、P的排泄量和CH4释放量的影响。结果,饲喂TMR4与饲喂TMR1和TMR6的奶牛相比,每头奶牛每年CH4释放量减少15.20Kg和89.84Kg;粪便排泄量减少1.37t和1.41t;N降低3.71kg和17.50kg;P减少2.59kg和4.07kg,比TMR1FCM提高10.54%（P〈0.05）;乳脂率增加9.67%（P〈0.05）;乳糖增加7.26%（P〈0.05）,能减少奶牛对土壤水源及空气的污染,提高奶牛的生态效益和经济效益。     

发酵天数对裹包全混合日粮发酵品质及有氧稳定性的影响

本试验旨在研究运用裹包发酵技术对全混合日粮(TMR)进行裹包发酵,确定适宜发酵天数,为裹包发酵全混合日粮(FTMR)在牧场中应用提供理论依据。试验以新鲜TMR为原料裹包发酵,于发酵0、3、7、15、30 d取样,分别设为D0、D3、D7、D15、D30共5个处理组,每组8个重复,测定其发酵品质、营养成分及微生物变化;同时将FTMR暴露到空气中,用多通道温度记录仪记录温度变化,并在1、3、5 d后取样分析,评定其有氧稳定性。结果表明:发酵7 d后乳酸含量为3.31%~3.52%DM(干物质基础),pH为4.43~4.39,氨态氮(NH_3-N)占总氮(TN)比例为2.58%~3.33%,丙酸在D7和D30处理组检出且小于0.2%DM,说明FTMR在D7、D15和D30发酵品质良好;有氧暴露期间,D0和D3组在暴露5 d后霉菌和酵母菌数大于5 log10CFU/g,样品温度高于环境温度2℃,说明已发生腐败;而D7、D15和D30组未出现上述状况,说明具有较高的有氧稳定性。综上表明,FTMR在发酵7 d后表现出良好的发酵品质,并具有较高的有氧稳定性。     

TMR制作粒度对肉牛增重与瘤胃微生物发酵的影响

为研究不同粒度全混合日粮(TMR)对肉牛增重和瘤胃发酵的影响,试验选取新疆褐牛(♂)与哈萨克牛(♀)杂交一代、体重为(305.6±5.6)kg的公牛70头,随机分为2组,预试期14 d,正试期44 d。日粮为不同搅拌时间的TMR,使用宾州筛进行粒度分布测定。对照组TMR搅拌时间为30 min,平均粒度为7.1 mm;试验组TMR搅拌时间为40 min,平均粒度为6.1 mm。结果表明:与对照组相比,试验组第1层(>19 mm)比例下降了6.3个百分点,第2层(>8 mm)和底层(≤1.18 mm)比例下降了3个百分点(P<0.01);结合剩料粒度分析结果研究发现,虽然延长搅拌时间后没有提高TMR总采食量,但提高了肉牛对TMR中粒度大于8 mm长纤维饲料的进食量,并提高了肉牛育肥全期平均日增重(P<0.05),饲料转化效率提高了12.7%(P=0.01);对TMR及宾州筛各层样品采用体外瘤胃发酵测试结果表明,延长TMR搅拌时间对体外干物质消化率、发酵产气量与产气速率、氨氮和挥发性脂肪酸(VFA)生成量无影响;但随着筛分粒度的下降,总VFA生成量升高(P=0.02),其中乙酸比例下降而丁酸比例升高(P<0.05)。综上所述,通过延长搅拌时间降低TMR粒度虽未能提高采食量,但可促进肉牛生长继而显著提高饲料转化效率,并有利于维持瘤胃微生物的正常发酵功能。