柱花草菠萝皮混合青贮发酵品质研究

研究柱花草菠萝皮不同比例混合青贮发酵品质。试验设4个处理，分别为100 %柱花草单独青贮(CK)、70 %柱花草+30 %菠萝皮(SP1)、60 %柱花草+40 %菠萝皮(SP2)、50 %柱花草+50 %菠萝皮(SP3)，青贮30 d后开窖取样，测定青贮饲料发酵品质。结果表明：与对照组相比，柱花草与菠萝皮混合青贮显著提高了乳酸含量，显著降低了pH值、丁酸和氨态氮/总氮，提高了发酵品质；各混合组随菠萝皮混合比例增大，乳酸增多，pH值和丁酸降低；SP2、SP3处理组pH值、乙酸、丙酸、挥发性脂肪酸和氨态氮/总氮无显著差异。从发酵品质和菠萝皮利用角度出发，50 %菠萝皮和柱花草混合青贮是可行的。     

不同添加剂对柱花草青贮品质的影响

以热研2号柱花草为原料， 通过直接青贮（CK）、 添加山梨酸（0.2％）、 蔗糖（2％）、 青贮宝（0.1％）等处理， 30 d后测定了柱花草青贮饲料pH值、 乳酸、 乙酸、 丙酸、丁酸等含量并分析其主要营养成分含量。结果表明： 柱花草直接青贮品质较差， 添加山梨酸、 蔗糖、 青贮宝等处理能降低pH值和提高乳酸含量， 添加2％蔗糖能极显著降低pH值(p<0.01)、 提高乳酸含量(p<0.05)， 改善青贮品质， 提高营养价值。     

添加酶制剂对饲用苎麻与麦麸混合青贮品质的影响

为了探究酶制剂对苎麻混合青贮品质的影响,本试验在苎麻与麦麸(80%苎麻+18%麦麸+2%蔗糖)混合青贮中分别添加10 mL蒸馏水(对照组)、纤维素酶2 g/kg、纤维素酶2 g/kg+半纤维素酶0.4 g/kg、纤维素酶2 g/kg+半纤维素酶0.4 g/kg+果胶酶0.7 g/kg,30天后开包取样分析各项指标。结果表明,苎麻与麦麸混合青贮发酵品质和营养品质均较好。与对照相比,添加酶制剂显著提高了碳水化合物、干物质和粗蛋白含量(P<0.05),显著降低了中性洗涤纤维、酸性洗涤纤维、粗纤维的含量和氨态氮/总氮比值(P<0.05),但是对pH值、乳酸、乙酸和丙酸含量无显著影响(P<0.05)。本试验条件下,添加酶制剂能够有效提高苎麻混合青贮的品质,单独添加纤维素酶与复合酶制剂无显著性差异,从节约成本角度考虑,单独添加纤维素酶组为最佳选择。     

添加有机酸改善木薯叶青贮品质和营养成分

为了改善木薯叶青贮品质,研究有机酸对木薯叶青贮品质及营养成分的影响,以确定青贮木薯叶最适合的有机酸种类及添加量。本研究以华南7号木薯幼嫩茎叶为原料进行青贮试验,设对照组、甲酸（0.2%）、乙酸（0.2%）和丙酸（0.2%）处理组,30 d后测定木薯叶青贮饲料pH、乳酸（LA）、乙酸（AA）、丙酸（PA）和丁酸（BA）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,添加有机酸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）。添加有机酸可以改善木薯叶青贮品质并提高营养价值,添加乙酸（0.2%）和丙酸（0.2%）青贮品质较好,可作为木薯叶青贮添加剂。     

热研2号柱花草和热研4号王草混合青贮对其营养成分及发酵品质的影响

为合理开发和利用热带牧草资源，研究热研2号柱花草和热研4号王草混合青贮对其营养成分及发酵品质的影响，以期筛选出适宜的混合青贮比例，为调制高品质的青贮饲料提供理论依据。本研究将热研4号王草和热研2号柱花草混合青贮比例分别设置为100∶0(CK)、85∶15(A1)、70∶30(A2)、55∶45(A3)4组，青贮30 d后开封取样检测。结果表明：A2组混合青贮感官评价最佳，随着热研2号柱花草比例的升高，pH和氨态氮/总氮（NH3-N/TN）值逐渐升高，A1、A2、A3组与CK组差异显著（P<0.05）；乳酸（LA）含量逐渐降低，A3组显著低于CK组（P<0.05）；各试验组乳酸/乙酸（LA/AA）值均大于2.6；且A2组丁酸（BA）显著低于其他各处理组（P<0.05）。随着热研2号柱花草比例升高，各处理组粗蛋白（CP）、干物质（DM）和粗脂肪（EE）含量随之升高，且显著高于CK组（P<0.05）；水溶性碳水化合物（WSC）含量呈上升趋势，且各试验组差异不显著（P>0.05）；中性洗涤纤维（NDF）逐渐降低，且各处理组间差异不显著（P>0.05）；各试验...     

王草菠萝皮混合青贮发酵品质研究

研究了王草菠萝皮不同比例混合青贮发酵品质。试验设5个处理,分别为王草单独青贮(CK)、90 %王草+10 %菠萝皮(KP1)、80 %王草+20 %菠萝皮(KP2)、70 %王草+30 %菠萝(KP3)、60 %王草+40 %菠萝皮(KP4)。青贮后第1、3、5、7、14、30天开窖取样,测定青贮饲料发酵品质。结果表明：与对照相比,王草与菠萝皮混合青贮显著提高了乳酸含量,显著降低了pH值和氨态氮/总氮;各混合处理组均未检测到丁酸,pH值、乙酸、丙酸、挥发性脂肪酸和氨态氮/总氮无显著差异。从发酵品质和菠萝皮利用角度出发,40 %菠萝皮和王草混合青贮是可行的。     

添加蔗糖和甲酸对红麻青贮饲料品质的影响

探讨甲酸和蔗糖两种添加剂对红麻青贮的影响。以刈割后的红麻为青贮原料,添加不同计量的蔗糖(10 g/kg,15 g/kg和20 g/kg)和甲酸(3 m L/kg,6 m L/kg和9 m L/kg),并分别设空白对照,密封青贮60 d后分析。结果显示,添加蔗糖或者甲酸能够显著提高粗蛋白含量(P0.05)和可溶性碳水化合物含量(P0.05)降低红麻青贮饲料的PH值,实验组p H均小于4.0,乳酸含量显著增加(P0.05),氨态氮含量显著降低(P0.05),实验组均没有检测到丁酸含量,青贮发酵品质良好;且在本实验研究范围内认为,添加20 g/kg的蔗糖得到的红麻青贮饲料的品质优于其他实验组,添加9 m L/kg的甲酸得到的红麻青贮饲料的品质优于其他实验组。     

砂仁茎叶和‘热研4号’王草混合青贮对其营养成分及发酵品质的影响

为有效利用热区农业废弃物砂仁茎叶及优质牧草资源,添加不同比例的砂仁茎叶与‘热研4号’王草混合青贮,研究其对王草营养成分和发酵品质的影响,筛选最佳混合青贮比例,以期提高饲料营养品质。按照完全随机设计试验,鲜重基础条件下,‘热研4号’王草和砂仁茎叶的混合比例依梯度分为100∶0（对照组）、90∶10（A₁组）、80∶20（A₂组）、70∶30（A₃组）,每组均加入10 mg/kg的EM菌,青贮30 d后开封进行检测分析。结果表明：各试验组乳酸（LA）/乙酸（AA）比值均大于2,均有少量丙酸（PA）和丁酸（BA）检出。A₂和A₃组感官品质为优良;随着砂仁茎叶比例升高,青贮料pH显著升高,各处理组的干物质（DM）、粗蛋白（CP）、粗脂肪（EE）和粗灰分（ASH）均呈现上升趋势;铵态氮/总氮（NH₃-N/TN）、LA和AA含量逐渐降低,且A₃组NH₃-N/TN显著低于CK和A₁组（P<0.05）;各处理组LA和AA含量显著低于对照组（P<0.05）,但各处理组间LA和AA含量差异不显著（P>0.05）;A₃组的DM、CP、EE和ASH含量显著高于CK（P<0.05）,水溶性碳水化合物（WSC）含量显著低于CK（P<0.05）,且A₁、A₂和A₃组间差异不显著（P>0.05）,中性洗涤纤维（NDF）和酸性洗涤纤维（ADF）含量显著低于CK（P<0.05）;从营养价值和发酵品质考虑,建议砂仁茎叶与‘热研4号’王草以30∶70比例混合青贮较为适宜。     

播期对青贮大麦产量和青贮品质的影响

为探究新疆北部地区播期对青贮大麦产量、青贮原料品质和青贮品质的影响,以3个大麦品种(系)(垦啤麦13、P13-3和甘啤4号)为材料,分别于3月18日、4月2日、4月17日播种,对其青贮农艺性状、干草产量、青贮原料营养成分和青贮品质进行分析。结果表明,随着播期的推迟,青贮大麦生育期大幅度缩短,4月17日播种时生育期较3月18日缩短22~23 d。晚播会显著降低大麦干草产量,晚播(4月17日)时3个品种(系)干草产量比早播(3月18日)降低15.2%~24.2%,其中垦啤麦13降幅最大。推迟播种使垦啤麦13和甘啤4号茎、穗的干物质分配比例下降,叶的干物质分配比例上升。晚播使P13-3和甘啤4号洗涤纤维含量(中性和酸性)和粗脂肪含量分别显著上升和下降,显著降低P13-3的粗蛋白含量,提高甘啤4号可溶性碳水化合物含量。播期对青贮品质影响因品种(系)而异,晚播降低了甘啤4号青贮的pH值、氨态氮含量,提高乳酸含量,对其他品种(系)无显著性影响。总体来看,新疆青贮大麦在外界条件允许的条件下,应适当早播。     

利用糖蜜和甜菜粕开发固态发酵饲料的初步探索

甜菜粕和糖蜜作为甜菜糖厂的两大主要副产物,有效提升其附加值对甜菜糖厂具有重要意义。由于甜菜湿粕的含水量偏高,不宜保存,而糖蜜下游客户单一,液体形态在运输储运上也存在不便之处,价格偏低。本文以甜菜粕和糖蜜为共同原料,通过添加乳酸菌种开展固态发酵试验,检测发酵后的理化指标并结合感官评价以综合评价固态发酵的质量。研究表明,在甜菜粕发酵中同时添加乳酸菌种和一定量糖蜜,发酵终产物的粗蛋白含量可达14.49%,粗纤维含量可达12.30%,干物质消化率可达82.14%,表明发酵进程可以强化甜菜粕原料的营养价值,提高动物对饲料的消化利用。此外,乳酸含量有所提高,可达2.65%,有利于降低发酵体系pH值,抑制杂菌生长,并且添加糖蜜的发酵甜菜粕感官品质也得到提升,具有酸香气味,整体感官评价达到了优等级。通过将甜菜粕与糖蜜共同发酵,可以提升发酵甜菜粕的品质,并有助于解决甜菜粕贮藏期短和糖蜜储存运输不便的问题。     

Effect of silage additives and wilting on silage fermentation, digestibility and intake, and on liveweight change of young cattle

Data from thirty-three experiments conducted at three ADAS Experimental Husbandry Farms were used to compare unwilted non-additive-treated silage with silage treated with formic acid, a formalin and formic-acid mixture, a calcium-formate and sodium-nitrite mixture, a formalin and sulphuric-acid mixture and wilted silage made without or with formic acid or a formalin and formic-acid mixture.
Formic acid significantly reduced pH and wilting significantly increased silage pH compared with other treatments. Formalin-acid mixtures significantly reduced pH compared with untreated silage. Formic acid in conjunction with formalin or wilting significantly increased water-soluble carbohydrate in silage compared with other treatments except wilting. Formic acid either alone or combined with either formalin or wilting significantly reduced silage butyric acid content compared with other treatments. Formic acid treatment either alone or combined with formalin significantly increased lactic acid as a proportion of total silage acids compared with other treatments except sulphuric acid-formalin.
All treatments significantly increased silage dry matter (DM) intake compared with untreated silage and intakes of wilted silage were significantly greater than of unwilted silage. Daily liveweight gains on all treatments were significantly higher than on untreated silage.
Herbage water-soluble carbohydrate necessary for successful preservation as silage without additive use was approximately 30 g (kg DM)⁻¹ and with additives containing formic acid it was approximately 25 g (kg DM)⁻¹.
It is suggested that formic acid application to unwilted silage either alone or in conjuction with formalin was the best treatment for improving subsequent preservation as silage, and that animal performance was enhanced by addition of acid-formalin additives to unwilted herbage or formic-acid application to unwilted or wilted herbage.     

Feeding Value and In situ Digestibility of Edible Canna for Silage

Abstract

To assess the potentiality of edible canna (Canna edulis Ker-Gawl.) as economically and environmentally sound animal feed, the feeding value of silage prepared from aboveground parts was examined, in parallel with studies on in situ digestion in the rumen among three local varieties. Contents of crude protein, acid and neutral detergent fibers and crude ash in canna silage were significantly higher, and that of nonstructural carbohydrate was significantly lower than in corn silage. The pH of corn and ‘yellow flower’ canna silages were significantly lower (3.8~3.9) than either ‘green stem’ or ‘red stem’ canna silage (4.4~4.9). The contents of lactic acid, acetic acid, total organic acid and the Flieg’s score of ‘yellow flower’ canna silage were equivalent or superior to those of corn silage. The rate of disappearance of dry matter in the rumen was significantly higher for corn silage than for canna silage, while the disappearance of neutral detergent fiber in canna silage was more rapid during the first 12 hours of incubation, but less rapid thereafter. The effective degradability of dry matter and organic matter of canna silage in the rumen was significantly higher than that of corn. Silage made from edible canna has a potential as a feed for ruminants.     

The influence of the carbohydrate fraction and additives on silage quality

Respiration losses, effect of sugar content, formic acid addition and inoculation were evaluated in relation to initial fermentation and silage quality in three experiments. Changes in the content of fermentable substrate during post–harvest respiration and initial fermentation were studied in the laboratory. Soluble carbohydrates were estimated as glucose, fructose, sucrose, fructans and starch by an enzymatic method.
About 70% of the sugars remained after 30 h of conventional wilting, as opposed to less than 50% in a chopped sample kept in the dark. During the first days of fermentation the metabolic activity was very intensive. Sugars, which accounted for 10% of the dry matter, were fermented within 4 d. There were indications, mainly in clover silages, that substances other than water-soluble carbohydrates were used as energy sources.
Low-sugar crops were obtained by shading the fields. After 3 d the sugar in the grass had decreased to half of the original content. This effect was less pronounced in clover. The amount of available substrate and dry matter (DM) content had a major influence on silage quality. In an unwilted crop at least 25 g of water-soluble carbohydrate was needed per kg of fresh material to obtain an acceptable silage quality in the controls, while 20 g was sufficient in inoculated silage. Formic acid addition makes the fermentation less sensitive to water–soluble carbohydrate content. Inoculation of willed silage increased lactic acid production and decreased the pH. There was also less variation in silage quality.     

RESEARCH NOTE

Data from twenty-two experiments conducted at tour ADAS Research Centres during 1980–92 were used to compare untreated silages with silages treated with formic acid, with or without added formalin, commercial inoculants or molasses. The sillages were made from herbage whose dry-matter (DM) and water-soluble carbohydrate (WSC) contents were 277 (s.e. 0.46) g DM kg⁻¹ and 36 (s.e. 8.1) g kg⁻¹ respectively. Inoculant use significantly decreased silage pH and ammonia-N, significantly increased lactic acid and total acid content, and decreased butyric acid and total short-chain fatty acids. Formic acid use significantly increased silage lactic acid and total acid content, and decreased butyric acid content, whereas formic acid+formalin significantly decreased silage ammonia-N level. Molasses had little effect upon silage fermentation. Improvements in silage fermentation, however, produced little benefit in terms of either silage DM intake or liveweight gain when the silages were offered to growing lambs.
It is suggested from the results that inoculant- and formic acid-based additives can be used to improve the fermentation of big-bale silages.     

A quantitative model of the ensilage process in lactate silages

A model of the ensilage process is presented which can be used to predict silage quality in lactate silages. The model simulates the major microbial and biochemical processes during ensilage, including aerobic respiration, hydrolysis of hemicellulose. growth and death of lactic acid bacteria and their production of lactic and acetic acids, reduction in pH, change in soluble sugar content, increase in osmotic potential, and proteolysis. The model is designed to operate on mixtures of grasses, legumes, or whole-plant corn. Parameters for the model are developed from published silage experiments and pure-culture bacterial studies. The model gives reasonably accurate predictions of key silage quality parameters, but further experimental work is needed on growth of lactic acid bacteria and on plant-enzyme proteolysis. Predicted final pH depends primarily on the pH at which bacterial growth and death rates are equal. Initial bacterial concentration affects the time to rapid pH change, while maximum bacterial growth rate affects the rate of decline thereafter.     

The effect of an additive containing non-protein nitrogen on some fermentation characteristics of maize silage

A non-protein nitrogen additive containing ammonia, molasses and minerals was applied to precision-chopped forage maize to raise the crude protein content of the ensiled crop from approximately 8% to 10, 14 or 16%. The dry matter content, total nitrogen, water-insoluble nitrogen, and water-soluble nitrogen concentrations were measured at ensiling and 2 and 8 weeks later. The pH and lactic, acetic, propionic and butyric acid contents of the resultant silage were determined 2 and 8 weeks after ensiling. The levels of crude protein achieved were 10.8, 11.5 and 14.2%, which are equivalent to recoveries in the silages of 108, 82 and 89% of the applied nitrogen. After 8 weeks the water-insoluble nitrogen content of the treated silages had increased while the water-soluble nitrogen content had decreased. The increase in water-insoluble nitrogen may have been due to either decreased proteolysis or increased levels of microbial protein. There was a significant increase of 0.6 units in the pH of the silage when comparing the control to the highest rate of additive application. The additive increased the levels of lactic and acetic acid in the maize silage.     

Total mixed ration silage containing elephant grass for small‐scale dairy farms

Alternatives need to be addressed for reducing losses in elephant grass (EG; Pennisetum purpureum) silages. Furthermore, smallholders lack information on the nutritional aspects of dairy farms. The aim of this study was to evaluate total mixed ration silage (TMR) combining fresh EG and concentrate ingredients, creating the following treatments: (i) EG silage (control); (ii) EG, corn and soya bean meal; (iii) EG, corn, soya bean meal and molasses; (iv) EG, citrus pulp and soya bean meal; and (v) EG, citrus pulp, soya bean meal and molasses. Five replicates of each treatment were ensiled in 15‐L plastic jars. The fermentation profile, chemical composition, microbial counts and aerobic stability were assessed. Three contrasts were tested, as follows: (i) control vs. TMR; (ii) TMR with corn vs. TMR with citrus pulp; and (iii) TMR with molasses vs. TMR without molasses. Variables were analysed through the PROC MIXED procedure of the SAS at the 5% level. The TMR had better fermentation profile, lower effluent production and longer aerobic stability compared to control. When the effect of corn was compared to citrus pulp among the TMR, silages with citrus pulp showed lower fermentation losses, non‐protein nitrogen and effluent production. The aerobic stability also improved with citrus pulp. Molasses did not affect the fermentation profile. Overall, lactic acid was the primary acid in all TMR. Nitrogen source (e.g., soya bean meal) can be used without compromising the fermentation process. TMR with citrus pulp showed better results than corn. TMR may be an alternative to optimize the use of EG on smallholdings.     

Voluntary feed intake and metabolism of sheep when lactic acid is administered in the feed or intraruminally

Four sheep in a 4 × 4 Latin Square experiment were offered ad libitum grass meal pellets alone or supplemented with lactic acid at 600, 800 or 1000 mmol per kg dry matter (DM) intake, either mixed into the feed or continuously infused intraruminally for 6-d periods. When added to the feed lactic acid did not significantly affect DM intake but when infused intraruminally it significantly reduced DM intake especially at the highest rate of infusion. In a second 4 × 4 Latin Square experiment, four sheep were offered ad libitum grass meal pellets alone or supplemented with lactic acid mixed into the pellets at 900, 1200 and 1500 mmol per kg DM for 15-d periods. There was a small reduction in intake on the three lactic acid treatments but this was not significant. In a third experiment the effects of intraruminal infusion with lactic acid was studied further with four sheep which received infusions of lactic acid at a fixed daily rate of 40 mmol per kg W^?0·75 per d or of an equal volume of distilled water for 3-d periods while being offered grass meal pellets ad libitum. Infusion with lactic acid resulted in reduced DM intake but the effect was less consistent than in Experiment 1. In all three experiments lactic acid supplementation had little effect on the pH and total volatile fatty acid concentration of rumen     

Protein supplementation of formic acid- and enzyme-treated silages. 1. Digestibilities, organic matter and fibre digestion

Two silages were made from perennial ryegrass ensiled without wilting in 2-t capacity silos with the application of either formic acid or an enzyme mixture of cellulases and hemicellulases. Effluent losses were monitored over the ensiling period. Subsequent silage analysis showed that the enzyme-treated silage had higher concentrations of residual water soluble carbohydrate, lactic acid and acetic acid, and lower concentrations of cellulose, ADF and NDF. Effluent production was higher with the enzyme silage (formic acid, 211 1 t^?1; enzyme, 2671 t^?1). The silages were either offered as the sole diet or supplemented with rapeseed meal at two levels (60 or 120 g fresh weight kg^?1 silage DM offered) to growing steers equipped with rumen cannulae and T-piece duodenal cannulae. Apparent whole tract digestibilities for DM, OM, N, ADF and NDF were similar for all diets although nitrogen retention (g d^?1) was increased with supplementation of both silages (formic acid, 21·1; formic acid + 60 g, 23·5; formic acid+ 120 g, 28·5; enzyme, 22·6; enzyme + 60 g, 25·8; enzyme+ 120 g, 31·6). Rumen pH, ammonia and total volatile fatty acids patterns were similar. Supplementation increased the amount of organic matter apparently digested in the rumen (ADOMR) with formic acid-treated silage but not with enzyme-treated silage. Liveweight gains were similar for both unsupplemented silages (0·49 kg d^?1). These increased to 0·55 and 0·65 kg d^?1 for formic + 60 and formic + 120 respectively. Liveweight gains for the corresponding enzyme-treated supplemented diets were 0·81 and 0·91 kg d^?1 respectively. Liveweight gains on supplemented enzyme-treated diets were significantly (P < 0·05) greater than those on formic acid-treated diets.