首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
An in vitro trial was conducted to investigate the effect of different inoculum sources (buffalo vs. cattle) on rumen fermentation and degradability. Incubations were carried out using rumen fluid obtained from buffalo or cattle fed the same diet [60% grass hay and 40% concentrate; 18 kg dry matter (DM)/day]. The fermentation kinetics of eight feeds commonly used in ruminant nutrition (alfalfa hay, barley meal, beet pulp, corn meal and silage, ryegrass hay and silage and soya bean meal s.e.) were studied with the in vitro gas production technique and rumen fermentation parameters (substrate disappearance, pH and volatile fatty acids production) were determined after 120 h of incubation. The linear relationship indicates that the microbial metabolic pathways of the two inocula for all the substrates were qualitatively similar, albeit often quantitatively different. In this in vitro study, a significant influence of rumen inoculum (buffalo vs. cow) on fermentation and degradability of the examined substrates was found. The differences in buffalo and cattle rumen fermentation can be explained with a different microbial activity of the two ruminant species, because of different amount of microbial population or microbial population constituted by different species of bacteria and protozoa.  相似文献   

2.
A 4 × 6 Youden square design was used to study manipulating effect of Yucca schidigera with or without nisin on rumen fermentation characteristics and microbial protein synthesis in sheep fed silage‐ and hay‐based diets. Four ruminally canulated wethers were given isonitrogenous diets of timothy silage and concentrate (85:15) (S), and timothy hay and concentrate (60:40) (H), on DM basis. The six experimental diets were: (i) S; (ii) S + 240 ppm of Yucca schidigera (SY); (iii) S + 240 ppm of Yucca schidigera + 6 mg/kg bodyweight (BW)0.75 of nisin (SYN); (iv) H; (v) H + 240 ppm of Yucca schidigera (HY); and (vi) H + 240 ppm of Yucca schidigera + 6 mg/kg BW0.75 of nisin (HYN). Rumen pH was higher (P < 0.01) in sheep fed SYN diet than those fed S diet. Concentration of ammonia‐N (NH3‐N) was significantly lower (P < 0.05) in sheep fed SY, SYN, HY, HYN than those of S and H. Total volatile fatty acids concentration was significantly lower (P < 0.05) in HYN than in H diet and tended to be higher in sheep fed H diets than those fed S diets. There was a significantly higher (P < 0.01) efficiency of microbial nitrogen synthesis in the rumen of sheep fed on HY diet than those fed on H diet.  相似文献   

3.
Six rumen-fistulated Merino sheep were used in a crossover design experiment to evaluate the effects of an exogenous fibrolytic enzyme preparation (12 g/d; ENZ), delivered directly into the rumen, on diet digestibility, ruminal fermentation, and microbial protein synthesis. The enzyme contained endoglucanase and xylanase activities. Sheep were fed a mixed grass hay:concentrate (70:30; DM basis) diet at a daily rate of 46.1 g/kg of BW(0.75). Samples of grass hay were incubated in situ in the rumen of each sheep to measure DM and NDF degradation. The supplementation with ENZ did not affect diet digestibility (P = 0.30 to 0.66), urinary excretion of purine derivatives (P = 0.34), ruminal pH (P = 0.46), or concentrations of NH(3)-N (P = 0.69) and total VFA (P = 0.97). In contrast, molar proportion of propionate were greater (P = 0.001) and acetate:propionate ratio was lower (P < 0.001) in ENZ-supplemented sheep. In addition, ENZ supplementation tended to increase (P = 0.06) numbers of cellulolytic bacteria at 4 h after feeding. Both the ruminally insoluble potentially degradable fraction of grass hay DM and its fractional rate of degradation were increased (P = 0.002 and 0.05, respectively) by ENZ treatment. Supplementation with ENZ also increased (P = 0.01 to 0.02) effective and potential degradability of grass hay DM and NDF. Ruminal fluid endoglucanase and xylanase activities were greater (P < 0.001 and 0.03, respectively) in ENZ-supplemented sheep than in control animals. It was found that ENZ supplementation did not affect either exoglucanase (P = 0.12) or amylase (P = 0.83) activity. The results indicate that supplementing ENZ directly into the rumen increased the fibrolytic activity and stimulated the growth of cellulolytic bacteria without a prefeeding feed-enzyme interaction.  相似文献   

4.
饲粮中添加燕麦干草对绵羊体外发酵的影响   总被引：1，自引：0，他引：1  
为明确燕麦干草不同添加量对绵羊瘤胃体外发酵的影响,选用6头体况相似、体重 (70.24±2.03) kg且装有永久性瘤胃瘘管的杂种(美利奴♂×蒙古羊♀)公羊作为瘤胃液供体动物进行体外发酵试验,按粗饲料中燕麦干草和青贮玉米比例(干物质基础)将饲粮分为C1组(精料+100%玉米青贮),C2组(精料+50%玉米青贮+50%燕麦干草)和C3组(精料+100%燕麦干草)。饲粮精粗比为35∶65。结果表明:1)饲粮中加入燕麦干草显著提高了体外发酵的产气量和甲烷产量(P<0.05);2)饲粮中加入燕麦干草对体外培养液pH没有明显影响,但显著提高了培养液NH3-N浓度(P<0.05),未明显改变试羊瘤胃丙酸摩尔比,但TVFA浓度、乙酸、丁酸摩尔比以及乙酸/丙酸上升;3)燕麦干草的加入显著提高了绵羊瘤胃体外发酵的IVDMD和IVCPD,对饲粮中营养物质的降解有促进作用;4)多项指标综合指数以C2组最高,C1组最低。由此可知,在精料水平相同的条件下,燕麦干草与青贮玉米1∶1混合作为粗饲料能改善绵羊的瘤胃内环境,提高瘤胃发酵能力,得到最大组合效应。  相似文献   

5.
The objective of the present study was to investigate the effects of α‐cyclodextrin‐allyl isothiocyanate (CD‐AI) on ruminal microbial methane production and rumen fermentation of corn starch, soluble potato starch or hay plus concentrate (1.5:1) by mixed rumen microorganisms. Diluted rumen fluid (30 mL) was incubated anaerobically at 38°C for 6 and 24 h with or without CD‐AI (0, 0.4, 0.8, 1.6 and 3.2 g/L). The pH of the medium was unchanged by CD‐AI in all substrates. The molar proportion of acetate was decreased and propionate was increased with a corresponding decrease in acetate : propionate ratio (P < 0.05). Total volatile fatty acids and butyrate were increased (P < 0.05). Ammonia‐N was decreased (P < 0.05). Except with soluble potato starch, numbers of protozoa were unchanged after 6 h. As concentration of CD‐AI increased from 0 to 3.2 g/L, fermentation of corn starch, soluble potato starch and hay plus concentrate resulted in decreased (P < 0.05) methane production of 49–100% (6 h) and 14–100% (24 h); 39–100% (6 h) and 16–100% (24 h); and 45–100% (6 h) and 17–100% (24 h), respectively. When hay plus concentrate was used as substrate, methanogenic bacteria were decreased (P < 0.05) with 0.8 g/L of CD‐AI after 6 h. Excluding the lower dose level (0.4 g/L) of CD‐AI, digestibility of neutral detergent fiber of hay plus concentrate was decreased (P < 0.05) after 24 h. A suitable level of CD‐AI could therefore be used as a supplement to inhibit methane production and improve rumen fermentation without detrimental effects on fiber digestion.  相似文献   

6.
The effects of monensin, 2-bromoethanesulfonic acid (2-BES) and pyromellitic diimide (diimide) on gas and volatile fatty acid (VFA) production by the rumen microbiota were compared in mixed culture. Oat hay, a hay-concentrate mixture (48% hay, 43% concentrate) and a soluble carbohydrate mixture were used as substrates for microbial growth. The highest concentrations of diimide (10 ppm) and 2-BES (30 microM) decreased methanogenesis by 97 and 76%, respectively, while H2 accumulation was increased 30- and 20-fold, respectively. The effect of monensin on methanogenesis was less dramatic as 10 ppm decreased CH4 accumulation 16% and H2 did not accumulate. Diimide and 2-BES decreased the acetate:propionate ratio with the hay (P less than .05) and soluble carbohydrate mixture (P less than .025). The numbers of saccharolytic, cellulolytic and methanogenic bacteria from sheep fed a diet with diimide (60 ppm) did not differ significantly from sheep fed a control diet. Semicontinuous culture incubations indicated that the mixed rumen microbial population could adapt and degrade diimide after 24 h of incubation.  相似文献   

7.
Two in vivo digestibility trials with sheep were conducted to identify the minimum period length of feeding a new diet to obtain reproducible values of nutritional variables onward and the minimum length of collection period as to obtain maximal precision for each variable. Trial 1 was conducted with ten Polwarth male sheep (34 ± 5 kg body weight (BW)) throughout three 21‐day periods, in a completely randomized two‐way crossover design. The animals were divided into two groups (Group A and B, n = 5 per group) which were fed ad libitum with a sequence of the following diets throughout the periods: Group A: hay – hay plus concentrate – hay; Group B: hay plus concentrate – hay – hay plus concentrate. The concentrate was included in a proportion of 0.33 of the total diet. The intake, and the faecal and urinary excretion were measured daily throughout the experiment. For evaluating rumen fermentation variables, in Trial 2 four Santa Inês male sheep (65 ± 5 kg BW) fitted with ruminal cannula were used. The animals were randomly divided into two groups (n = 2 per group), and the trial was conducted through four 21 days experimental period, in a three‐way crossover design, using experimental diets and feeding management similar to Trial 1. The results indicated that, even though no clear or consistent steady‐state condition was identified for rumen fermentation or urinary excretion variables, the adaptation period for measuring OM digestibility in in vivo trials with sheep fed ad libitum where the diet shifts from one of only hay to another containing concentrate, or vice‐versa, should be at least 12 days long. Moreover, although no precision improvement was obtained by increasing the collection period above 1 day for measuring OM digestibility, the minimal length of collection period should be 4 days for measuring faecal excretion variables and 7 days for measuring urinary excretion variables.  相似文献   

8.
为探索红花油对瘤胃微生物发酵动力学的可能影响,试验以安装有永久性瘤胃瘘管的中国美利奴羊作为瘤胃微生物的供体动物,采用体外产气量法研究饲粮添加不同水平的红花油对绵羊瘤胃发酵动力学的影响。红花油的添加水平分别设0(对照组)、1%、2%和3%。结果表明:日粮添加2%和3%的红花油使产气速率和最大产气量明显低于对照组(P<0.05)。不同水平的红花油并未显著改变发酵液pH值、NH3-N浓度、CMCase及XYLase活性(P>0.05)。3%组的DM降解率略低于对照组(P<0.05),但与其他2个处理组差异不显著(P>0.05)。各处理组的NDF降解率较对照组也略有降低(P<0.05)。总挥发酸(TVFA)浓度、乙酸、丙酸摩尔百分比和乙丙酸比等指标各组间均差异不显著(P>0.05)。综上所述,饲粮中添加不超过3%水平的红花油对绵羊瘤胃发酵动力学没有负面影响。  相似文献   

9.
Two‐phase olive cake (2POC) is the by‐product obtained from the so called ‘two‐phase’ procedure to extract olive oil by mechanical methods. After the mechanical extraction the 2POC is dried and most of the remaining oil extracted by chemical means. The production of the crude by‐product may reach more than 4 millions t/year in Spain ( MAPA, 2003 ), most of it in areas (Southeast) with shortage of pastures and conventional feeds for ruminants. Six continuous fermenters, inoculated with ruminal liquor from wethers or goats, were fed lucerne hay (LH); LH plus a concentrate including dried two‐phase olive cake (LHCO) and; diet LHCO added with polyethylene glycol (LHCOP). The highest pH values and ammonia N (NH3‐N) output were found in fermenters fed diet LH (6.19 and 6.35 for pH, and 53.7 and 68.9 mg NH3N/day, respectively, in fermentes inoculated with rumen liquor from sheep and goats) without differences due to the inoculum origin. The digestibility of carbohydrates (CHO) was affected (p < 0.001) by inoculum (67.0 and 58.8%, respectively, for goats and wethers) the lowest values being for diet LHCO (53.2 and 57.0% with inoculum from wethers and goats, respectively). The main volatile fatty acid (VFA) was acetic acid with higher (p < 0.01) values in fermenters with inoculum from goats than from wethers (80.2 and 63.0 mmol/day respectively). The efficiency of bacterial protein synthesis (EBS) was not different (p > 0.05) with inoculum from wethers and goats [26.4 and 28.1 and 35.2 and 33.5 g bacterial N/kg digested CHO, respectively, obtained by using diamino pimelic acid (DAPA) and purine bases (PB) as microbial markers]. The lowest (p < 0.05) values were found in fermenters fed diets LHCOP and LH, estimated, respectively, from DAPA and PB (21.9 and 29.0 g bacterial N/kg digested CHO). The substitution of a part of lucerne hay by a concentrate including dried 2POC does not seem to cause important differences in efficiency of VFA production. Results concerning bacterial protein synthesis are not so clear since values estimated from DAPA and PB did not show similar trends. Neither inoculum origin nor PEG had important effects on fermentation characteristics. The DAPA could be an adequate marker in continuous fermenters, with comparative purposes, as protozoa are not present and, estimated protein synthesis values are similar to those obtained in vivo with similar diets using urinary excretion of PD ( Yáñez Ruiz et al., 2004b ). Further research is needed to state the optimal proportion of 2POC in practical diets for ruminants at both maintenance and production stages.  相似文献   

10.
In this study, the relative contribution of different microbial groups to ruminal metabolism was investigated for different diets. The rumen microbial cultures included whole rumen fluid, fungi + protozoa, bacteria + protozoa, protozoa and bacteria + fungi and were established by physical and chemical methods. Gas production, short‐chain fatty acid (SCFA) and ammonium production were measured at 24 hr in in vitro incubations using the Hohenheim gas test (HGT) procedure. Seven donor animal diets with different concentrate‐to‐roughage ratios (C:R: 10:90, 30:70, 50:50, 70:30, 70:30BC (BC = NaHCO3), 90:10 and 90:10BC) and five HGT diets (C:R: 10:90, 30:70, 50:50, 70:30 and 90:10) were formulated. Incubations in the HGT were always based on inoculum from sheep diets with the respective C:R ratio. Gas and ammonium production increased (p < 0.001) as a result of a gradual increase in concentrate proportion of the diets. In general, SCFA production followed the same trend. Whole rumen fluid and bacteria + fungi produced approximately 50% higher gas volume than protozoa and fungi + protozoa fractions, whereas gas production with bacteria + protozoa was at an intermediate level. Coculture of protozoa either with bacteria or with fungi produced more ammonium. Populations without bacteria were characterized by a particularly high acetate/propionate ratio. Although an interaction between microbial group and diet was observed for several variables, no clear direction could be established. Manipulating rumen fluid by selectively suppressing specific rumen microbial groups may be a helpful tool in elucidating their role in nutrient degradation and turnover in vitro.  相似文献   

11.
本试验旨在明确燕麦干草与全株玉米青贮按不同比例组合对绵羊瘤胃发酵的影响。选用9头体重为(70.24±2.03)kg、体况相似且装有永久性瘤胃瘘管的杂种(美利奴×蒙古羊♀)公羊作为试验动物,按过渡期称重结果分成3组,每组3只。按燕麦干草和全株玉米青贮占粗饲料比例(干物质基础)将饲粮分为A1(100%全株玉米青贮)、A2(50%全株玉米青贮+50%燕麦干草)和A3(100%燕麦干草)3种,3种饲粮精粗比均为35∶65。采用3×3拉丁方设计,进行3期试验,每期22 d(预试期15 d,正试期7 d),正试期最后3 d采样。结果显示:1)与100%全株玉米青贮相比,以50%全株玉米青贮+50%燕麦干草或100%燕麦干草为粗饲料对绵羊瘤胃液p H和总氮浓度平均值没有产生显著影响(P0.05),但显著降低了瘤胃液氨态氮(NH3-N)、尿素氮和血浆尿素氮浓度平均值(P0.05),同时以50%全株玉米青贮+50%燕麦干草为粗饲料还显著提高了瘤胃液蛋白氮浓度平均值(P0.05)。此外,A2组的瘤胃液p H和总氮浓度平均值稍高于A3组,瘤胃液蛋白氮浓度平均值较A3组增加了8.97%,瘤胃液和血浆尿素氮浓度平均值稍低于A3组,但差异均不显著(P0.05),而瘤胃液NH3-N浓度平均值则显著低于A3组(P0.05)。2)粗饲料中燕麦干草的加入并未显著改变绵羊瘤胃液总挥发性脂肪酸浓度和丙酸摩尔比平均值(P0.05),升高了瘤胃液乙酸、丁酸摩尔比以及乙酸/丙酸平均值,且A3组与A1组差异显著(P0.05)。由此可知,在精料相同、精粗比为35∶65的条件下,用50%全贮玉米青贮和50%燕麦干草混合作为粗饲料可以改善绵羊的瘤胃内环境而适宜瘤胃微生物生长,提高瘤胃微生物活性及其对氨(NH3)的利用率,有助于微生物蛋白的合成,升高瘤胃乙酸的摩尔比及乙酸/丙酸。  相似文献   

12.
The effects of feeding different levels of forages and concentrate, in a discontinuous feeding pattern, on the efficiency of feed utilisation and rumen function were studied using rumen fistulated sheep. Experiment 1 was a 4 × 4 latin square design to determine the whole tract digestibility and rumen characteristics of diets comprising 15% (C15), 25% (C25), 35% (C35) and 45% (C45) concentrate (energy-dense dairy pellets) with the rest of the diet being a combination of fresh short rotation ryegrass (Lolium mutiforum) and conserved (lucerne hay and maize silage) forages. In Experiment 2, the rumen degradation characteristics of feed ingredients were determined using the nylon bag technique. Daily dry matter intake (either expressed as g/kg LW or g/kg W 0.75) was 10% lower (p = 0.03) for the C15 diet compared with C25, C35 and C45 diets. The apparent in vivo digestibility of dry matter (DM) for C15 diet was 4% higher (p = 0.04) than the C35 and C45 diets which may be attributed to the high quality of the forage (ryegrass) used.Fibre digestibility decreased as proportion of concentrate in the diet increased. However, this was unlikely due to changes in the rumen fermentation pattern, as neither pH (6.1 ± 0.23) nor ammonia concentration (24.4 ± 6 mg/dl), were different (p > 0.05) among diets. Instead, the lower fibre digestion was most likely the result of different type and proportion of fibre among diets, as total rumen degradability and rate of fibre degradation in the rumen were higher (p = 0.001) for ryegrass than for other feedstuffs. There was no significant difference in total nitrogen balance and urinary allantoin excretion among diets, which indicated similar total microbial protein synthesis (MPS). The asynchrony observed, for N and energy availability in the rumen for different diets using Sinclair et al. [Sinclair, L.A., Garnsworthy, P.C., Newbold, J.R., Buttery, P.J., 1993. Effect of synchronizing the rate of dietary energy and nitrogen release on rumen fermentation and microbial protein synthesis in sheep. J. Agric. Sci. 120, 251–263] equation, was due to the feeding pattern used in this study leading to excess of N in relation to total organic matter digested in the rumen. In conclusion, feeding concentrates in the diets as PMR with conserved forages in a discontinuous feeding pattern may be valuable to develop feeding strategies in a pasture based system for high producing dairy cows without affecting the rumen system.  相似文献   

13.
The feeding value of a mixture of sorghum and soybeans plants, either fresh or ensiled, was evaluated with sheep. Sorghum and soybeans were harvested during the Cuban rainy season and ensiled in a ratio of 0.6/0.4 (w/w, as feed) with molasses and a bacterial inoculant. Silos were opened between 162 and 182 d post ensiling during the Cuban dry season and silages were fed to six pelibuey sheep (including two fistulated). Six other sheep (also including two fistulated) were fed sorghum and soybean in the same proportion, but freshly harvested during the dry season. The experiment lasted 21 d (14 d adaptation and 7 d data collection period). Silage quality parameters included pH, ammonia, lactate, and short chain fatty acids (SCFA). Further, both fresh and ensiled diets were offered to study the rumen fermentation characteristics (pH, ammonia, lactate, SCFA, in situ degradability and methane), duodenal flow of microbial protein (assessed through urinary purine derivatives secretion), fecal degradability of nutrients and urinary N excretion. From these measurements ME value and degradable CP supply at the small intestine (DCPSI) were estimated. Silage was of excellent quality. Compared to fresh forage feeding silage increased molar propionate proportion and rumen microbial protein synthesis and reduced methane emission. Fresh forage showed lower rumen degradability and total digestibility. Further, the higher ME concentration (11.2 vs. 10.3 MJ/kg DM) and DCPSI (84.7 vs. 56.1 g/kg DM) of the silage would allow a higher milk production or daily gain as compared with fresh forage available during the Cuban dry season.  相似文献   

14.
The interaction of retention time in the rumen and concentrate diet on methane production in vitro and acetate:propionate ratio was examined. Twenty-four fistulated sheep were used in a complete factorial design with the sheep randomly divided into 4 groups. The sheep had a 5-wk acclimatization period on an oaten chaff diet, followed by two 3-wk diet phases. Two of the 4 groups were maintained on the oaten chaff diet for the duration of the experiment, with pot scrubbers added to the rumen of 1 of the 2 groups. The remaining 2 groups were offered a low-grain diet (35% grain) in the first diet phase followed by a high-grain diet (70% grain) in the second diet phase. Pot scrubbers were also added to the rumen of 1 of these 2 groups of grain-fed sheep. Pot scrubbers in combination with a low-grain diet decreased the amount of methane produced in vitro from 4.25 to 3.71 mmol/mL of digesta when compared with oaten chaff-fed sheep without pot scrubbers (P < 0.05). The acetate:propionate ratio was 1.6 in sheep fed a high-grain diet with pot scrubbers compared with 2.4 in sheep fed a high-grain diet without pot scrubbers in their rumen (P < 0.05). At high levels of grain, when employing a multivariate statistical analysis including all data, sheep given the combined treatment of grain and pot scrubbers were different from all other sheep groups in this experiment (P < 0.05). Furthermore, sheep fed a high-grain diet were different from sheep receiving the oaten chaff diets with and without pot scrubbers (P < 0.01 and P < 0.05, respectively). In conclusion, pot scrubbers combined with grain alter the rumen fermentation, and introducing pot scrubbers into the rumens of livestock consuming low levels of grain may be a way to lower methane emissions.  相似文献   

15.
Efficient red deer supplementary feeding depends on estimations of the nutritive value of offered feeds, frequently estimated with the use of equations derived from domestic ruminants. The aim of this study was to compare the 24‐hour in vitro true dry matter degradability (ivTD24), in vitro gas production (GP) kinetic parameters, GP in 24 hr of incubation (GAS24) and short‐chain fatty acid (SCFA) and microbial biomass (MBS) produced after 24‐hour incubation of feeds in inoculum prepared from sheep and red deer rumen fluid. Eleven feeds, frequently consumed by red deer in Slovenia, which occur either naturally (two fresh grasses, chestnut fruits and common and sessile oak acorns) or are fed as winter supplemental feeds (two grass hays, two grass silages, apple pomace, fresh sugar beetroot), were investigated. The in vitro GP kinetic parameters, GAS24 and ivTD24, did not differ between animal species. Amounts of SCFAs were greater (p < 0.05) when feeds were incubated in sheep inoculum, while molar proportions of acetic and propionic acids did not differ. Molar proportions of butyric acid produced during incubation of high fibre feeds did not differ between animal species, but were higher (p < 0.05) when feeds high in starch or sugar were incubated in red deer inoculum. Greater production of SCFA by sheep rumen microbes suggests better coverage of host animal with energy precursors, while greater production of MBS by red deer rumen microbes suggests better coverage of host animal with protein. Results also suggest that rumens of sheep and red deer are inhabited by different microbial communities, which did not affect the extent of in vitro GP and degradation of feeds used in the present experiment. However, the possibility exists that the divergent nutrient use could be a consequence of different priming by different feeds of the donor animal diets.  相似文献   

16.
The objective of this study was to investigate the effect of nisin and monensin on rumen fermentation of diets containing hay and barley (80:20%) in artificial rumen (Rusitec system). The Rusitec system consisted of four fermentation vessels (V1, V2, V3, V4): V1 was without additives (control), V2 received daily 2 mg of nisin, V3 involved 5 mg of monensin and V4 combination of 2 mg of nisin with 5 mg of monensin. After an adaptation period (7 days), the fermentation parameters were determined for six consecutive days. Compared to control diet, the addition of nisin resulted in an increase (P < 0.05) of hemicellulose degradation, acetate, propionate (mmol.day-1) production and energetic efficiency of VFA (E), decrease of butyrate production. Nisin had no effect on dry matter (DM), organic matter (OM), cellulose and detergent fiber degradation, production of total gas, methane and efficiency of microbial synthesis. The addition of monensin resulted in an decrease of DM, OM (P < 0.05), cellulose, hemicellulose, detergent fiber degradation (P < 0.001), total gas, methane and ammonia nitrogen (NH3-N) production. Monensin also significantly decreased acetate, butyrate, L-lactate (mmol.day-1) production and it increased propionate production (P > 0.001) and efficiency of microbial synthesis. The combined effect of nisin and monensin in V4 was similar to the effect of monensin in V3 compared to control. Then, the effect of additive monensin was dominant over nisin. In conclusion, our results indicate that nisin was less effective than monensin on some fermentation parameters (important for the improvement of the efficiency of utilization of the diet by ruminants) in artificial rumen.  相似文献   

17.
选用3只健康并安装永久性瘤胃瘘管的杂种羯羊,平均体重为24 kg,采用3×3无重复拉丁方试验设计,用3种不同日粮(全混合颗粒料日粮、粉碎精料+铡短粗料日粮和未粉碎精料+铡短粗料日粮)来研究对绵羊瘤胃挥发性脂肪酸(VFA)浓度的影响。结果表明,采食未粉碎精料+铡短粗料日粮绵羊的瘤胃总挥发性脂肪酸(TVFA)浓度显著高于采食全混合颗粒料日粮绵羊(P＜0.05),采食未粉碎精料+铡短粗料及粉碎精料+铡短粗料日粮的绵羊瘤胃丙酸摩尔比显著或极显著高于采食全混合颗粒料日粮绵羊(P＜0.05,P＜0.01),而(戊酸+异戊酸)摩尔比极显著低于全混合颗粒料日粮绵羊(P＜0.01),乙酸/丙酸显著或极显著低于采食全混合颗粒料日粮绵羊(P＜0.05,P＜0.01)。因此,用粉碎精料+铡短粗料或未粉碎精料+铡短粗料日粮饲喂绵羊能改善绵羊瘤胃发酵类型。  相似文献   

18.
Six Japanese Black (Wagyu) steers (average initial weight 467 ± 45 kg) fitted with a ruminal cannula were used in a split‐plot design experiment comprising a 3 × 3 Latin square design (whole‐plot) and a randomized block design (subplot). The whole‐plot treatments were three different feeding levels of urea‐treated potato pulp (PP) silage‐based concentrate: 1.00%, 1.75% and 2.50% of body weight (BW) (on a dry matter (DM) basis). The subplot treatments consisted of the concentrate formulated to contain either soybean meal (SBM) as a rapidly rumen‐degraded protein source or corn gluten meal (CGM) as a slowly degraded protein source. Dry matter intake tended to be lower (P = 0.071) for CGM (8.9 kg/day) than for SBM (9.4 kg/day). Protein sources had no significant effect on digestibility and in situ degradation. Ruminal ammonia nitrogen (NH3‐N) was lower (P = 0.033) for CGM (7.5 mg/dL) than for SBM (9.5 mg/dL). Protein sources did not affect ruminal pH and the total volatile fatty acids (VFA) concentrations. The molar proportions of ruminal acetate and valerate were higher (P = 0.032) for CGM than for SBM. The maximum daily intake of the PP silage‐based concentrate expressed as a percentage of BW was approximately 1.4% of BW. Dry matter intake was higher (P = 0.046) for steers fed at 1.0% of BW of the PP silage‐based concentrate than for steers fed at 1.75% or 2.5% of BW of the concentrate. The feeding levels of the PP silage‐based concentrate had no effect on DM and nutrients digestibility, except for crude protein (CP) digestibility. CP digestibility tended to be lower (P = 0.071) for steers fed at 1.75% of BW of the PP silage‐based concentrate than for steers fed at 1.0% or 2.5% of BW of the concentrate. The feeding levels of the PP silage‐based concentrate also did not affect the in situ degradation parameter of hay and PP silage. The feeding levels of the PP silage‐based concentrate did not affect ruminal pH, NH3‐N and total VFA concentrations. The molar proportion of acetate was highest for steers fed at 1.0% of BW of the concentrate. In conclusion, in the urea‐treated PP silage‐based concentrate, CGM seems to be more effective than SBM for stabilizing the ruminal NH3‐N concentration and to be advantageous for fiber digestion in the rumen. The feeding levels of the PP silage‐based concentrate did not change the amount of VFA production in the rumen and the DM digestibility.  相似文献   

19.
Six lactating Holstein cows were divided into two groups (n = 3) and used in a double reversal trial with three periods of 14 days each to evaluate the rumen fermentation, milk production and milk composition of cows fed brewer's grain (BG). The control diets contained 14% chopped Sudangrass hay, 24% corn silage, 18% alfalfa hay cube, 34% concentrate mixture‐1 and 10% concentrate mixture‐2 (wheat bran, soybean meal and cottonseed). In the experimental diet, wet BG replaced the concentrate mixture‐2. The protozoal population, concentration of ammonia‐N and volatile fatty acids in the ruminal fluid did not differ between the control and BG diets. The molar percentage of acetic acid was significantly higher (P < 0.05) with the BG diet at 5 h after feeding. The milk yield, the percentage of protein, lactose, solids not‐fat and somatic cell counts of milk did not differ between the two diets. The percentage of milk fat tended to increase with the BG diet. The BG diet significantly increased the proportions of C18:0 and C18:1 in milk fat (P < 0.01, P < 0.05, respectively) and tended to increase that of conjugated linoleic acid.  相似文献   

20.
Pure ochratoxin A (OA) was added to buffered rumen fluid collected from two fistulated cows and incubated under anaerobic conditions. Both animals were fed six diets containing grass, grass silage or hay, and two different amounts of concentrate consisting of barley and soybean meal. Four incubations per animal and diet were carried out at consecutive days. The concentration of OA declined exponentially to a very low or non-detectable level under all conditions examined, with half-lives at 0.51 to 2.76 h. The disappearance of OA was accompanied by the appearance of ochratoxin alpha (O alpha) with an average amount of O alpha formed relative to the disappearance of OA near 100%, independent of diet and animal. Based on four incubations per animal and diet the rate of OA disappearance was affected (P < 0.1) by the origin of rumen fluid from two animals, as well as by the type of basic component and amount of concentrate in the diet, with interactions between these factors. The disappearance of OA mostly was accelerated (P < 0.1) by replacing grass silage or hay by fresh grass and by increasing the content of concentrate from 10 to 50% of dry matter. It is concluded that the capacity of the rumen to detoxify OA is not limited by the yield of Oa from OA but is strongly dependent on animal and diet.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号