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1.
Silages were made from the first cut of a predominantly perennial ryegrass sward. The silages were either untreated (W) or treated with formic acid (31 t−1, F) or with 106 lactic acid bacteria (LAB) g−1 grass of each of three strains alone (A. Lactobacillus plantarum MTD1; B, Pediococcus species 6A2; C, L. plantarum 6A6) or in combination (AB. AC) to give seven treatments. The silage fermentation in 10-kg silos was followed chemically and microbiologically and the nutritive value of selected treatments evaluated using 2-t silos.
The control silage (W) fermented well. Addition of formic acid restricted fermentation and produced a silage with a high ethanol concentration. After day 4, all inoculated silages had lower pH values and higher lactic acid concentrations and a higher ratio of lactic acid to acetic acid than the control silage. Chemically there was little difference between the inoculated silages in terms of final composition. Microbiologically the LAB applied in treatments B and C dominated the LAB populations in those silages when applied alone; however, they were suppressed when applied in combination with inoculant A.
When fed to sheep, the intake of the formic acid-treated silage was significantly ( P < 0·01) lower than that of the other silages and the intake of silage treated with inoculant A significantly ( P < 0·001) higher than that of silages treated with inoculants B and C. The apparent organic matter ( P < 0·001) and nitrogen ( P < 0·01) digestibilities of the formic acid-treated silage were also significantly lower than those of the other silages.  相似文献   

2.
Lucerne (DM 236 g kg-1, WSC 49 g (kg DM)-1) was ensiled in test-tube silos with or without either glucose or fructose and with or without one of two commercial inoculants. The WSC content of the forage as ensiled was too low to obtain a well preserved untreated silage. By day 4 the pH values of the silages with added sugar or inoculant were significantly lower (P< 0·001) than the control silage. A satisfactory fermentation was attained only in the silages to which sugar and an inoculant had been added. These silages had a lower pH, more protein-N (P< 0·001), less ammonia-N (P<0·001), a faster increase in counts of lactic acid bacteria, and decrease in counts of coliforms than the other silages. Homo-fermentative lactic acid bacteria dominated the fermentation in the inoculated silages while leuconostocs dominated the early stages of fermentation in the control silages. The results indicate that if there is insufficient sugar in the original crop, then the bacteria in an inoculant will not be able to produce enough lactic acid to lower the pH to an acceptable level. This has important implications for the ensilage of lucerne and other highly buffered low sugar crops.  相似文献   

3.
This study was aimed to perform a screening of Lactobacillus buchneri strains from maize silage and use them as inoculant in maize and sugarcane silages. In all, 151 lactic acid bacteria (LAB) strains were isolated from whole‐plant maize silage, and their identification was based on the sequence analysis of 16S rDNA. In total, 15 strains were categorized to the L. buchneri group and eight of these were selected based on growth rate and fermentation pattern. The selected strains were evaluated on fermentation and aerobic stability of maize and sugarcane silages. For maize, the inoculated silages had lower pH and higher LAB population, but lower acetic acid concentration in comparison with the untreated control silage. For sugarcane silage, the strains 56.1, 56.4 and 40788 resulted in highest dry‐matter (DM) content and lowest DM losses. However, only the strain 40788 showed lowest counts of yeasts and moulds. Sugarcane silages inoculated with the strains 56.9, 56.26 and the untreated control silage showed highest concentrations of lactic acid and ethanol, besides the great DM losses. Even so, for both crops, the aerobic stability was not affected by inoculation. After air exposure, all silages increased temperature and had high population of yeast and moulds. Nevertheless, the strains 56.1 and 56.4 are promising for use as a silage inoculant.  相似文献   

4.
Two 2×2 factorial experiments are described in which a bacterial inoculant being developed as a silage additive and containing a strain of Lacto-bacillus plantarum (Ecosyl, ICI plc) was evaluated at two harvests (18 July and 30 September 1985) of two swards (perennial ryegrass and permanent pasture) in difficult ensiling conditions. On each occasion erbage was ensiled with and without inoculant using two 0·5–t capacity steel tower silos per treatment. The contents of the two replicate silos per treatment were combined for feeding to cross-bred wethers in digestibility and metabolizable energy (ME) partition studies.
Overall, inoculated herbage declined in pH post-harvest at a faster rate than control herbage (p<0·001) and three out of the four inoculated silages had lower pH, ammonia-N, acetate and alcohol and higher residual soluble carbohydrate content (p<0·001) than control. Significantly higher digestibility of nutrients (P<0·05) was found in three of the inoculant-treated silages and these also had significantly higher ME values than control (P<0·001), (10·58 and 8·77 MJ kg tol DM−1 for the treated and untreated silages respectively). The use of inoculant on herbage of only moderate ensiling potential therefore, produced significant improvements in fermentation quality and feeding value over control.  相似文献   

5.
Various management practices (e.g. wilting, application of silage additives or adding a grass component) can be used to improve silage fermentation of pure red clover (Trifolium pratense L.). Therefore, the aim of this laboratory ensiling study was to investigate the effects of varying proportions of red clover and perennial ryegrass (100/0, 66/33, 33/66, 0/100) on silage quality during two consecutive years. In addition, two wilting levels [target dry matter (DM): 300 vs. 400 g kg?1] in combination with lactic acid bacteria (LAB) additives were tested. Herbage was ensiled, either untreated or inoculated with homofermentative LAB (low wilted) or homo‐ and heterofermentative LAB (high wilted). In most cases, lactic and acetic acid decreased as the proportions of ryegrass were increased. Data concerning ammonia‐N concentrations showed considerable differences between cuts and years. Silages treated with homofermentative LAB generally had high lactic acid and low final pH, whereas acetic acid and 1,2‐propanediol tended to be higher when homo‐ and heterofermentative LAB were applied. Inoculants had a positive effect on DM losses and ammonia‐N in only a few silages. Wilting decreased DM losses and fermentation acids at most cuts, irrespective of the grass/clover ratio in the herbage mixture. There was a strong year effect on the organic matter digestibility (DOM) of the silages. In conclusion, the optimal strategy for successful silage fermentation of red clover is the ensiling in mixtures with ryegrass. Furthermore, herbage should be wilted to a DM content of about 300–350 g kg?1. The application of LAB inoculants did not alter the DOM but did improve silage fermentation.  相似文献   

6.
The aim was to evaluate the effects of adding a novel Lactobacillus buchneri strain and a commercial inoculant on the fermentation and aerobic stability of sugar cane silages (Saccharum spp.). In the first experiment samples were collected from sugar cane silage at 5, 20, 40 and 80 d after ensilage in experimental silos and microorganisms belonging to the Lactobacillus genus were isolated and identified, with a wild strain of L. buchneri, UFLA SIL 72, being selected as an inoculant. In the second experiment sugar cane was inoculated with either the novel bacteria or a commercial inoculant at the moment of ensiling and compared with a control silage prepared without an inoculant. Experimental silos were opened at 0, 3, 10, 30, 60 and 90 d of ensilage and their chemical composition measured. The silages opened after 90 d were also assessed for aerobic stability. The addition of L. buchneri resulted in a higher concentration of acetic acid and reduced populations of yeasts in silage compared to the other silage treatments, and a lower ethanol concentration in the silage. The novel L. buchneri isolate and the commercial inoculant also improved aerobic stability of the sugar cane silages. It was concluded that the addition of the novel inoculants L. buchneri UFLA SIL 72 to sugar cane silage can be recommended.  相似文献   

7.
Re‐ensiling of previously ensiled forage has been a common practice in Brazil, and the use of inoculants may provide a means of reducing dry‐matter (DM) loss. This study aimed to determine the effect of re‐ensiling and the use of microbial inoculants on the quality of sorghum silage. Treatments were presence/absence of an inoculant (Lactobacillus plantarum and Propionibacterium acidipropionici) in the silage, and the re‐ensiling, or not, of the material after 24 h of exposure to air, and these were tested in a factorial 2 × 2 design. Losses due to gas, effluent and total DM were assessed, as were the fermentation characteristics, chemical composition, aerobic stability, and aerobic counts of microorganisms. Effluent loss was higher in re‐ensiled silage, and these silages had lower lactic acid content and higher levels of acetic and propionic acids. The in vitro DM digestibility was lower in the re‐ensiled sorghum silages. The re‐ensiled silage had higher aerobic stability. The inoculant only increased the acetic acid content of the silage. The re‐ensiling of sorghum silage increased effluent loss by 71·2%, and reduced DM digestibility by 5·35%. The use of inoculant did not influence the quality of sorghum silage.  相似文献   

8.
Three silages were prepared from herbage treated with either an inoculant (Ecosyl, Imperial Chemical Industries plc) at 3.21 t?1, formic acid (850 g kg?1, Add F BP Chemicals International Ltd) at 2·3 1 t?1, or no additive (control). The herbage used was the first regrowth from perennial ryegrass swards. It was ensiled unwilted, and had mean dry matter and water soluble carbohydrate concentrations at ensiling of 154 and 24·1 g kg?1 respectively. Time course studies showed only minor effects of additive treatment on fermentation patterns within the silo and all three silages had good fermentations. Over an 88 d feeding period, commencing on day 7 of lactation, forty-eight British Friesian cows were used to evaluate the silages in a three-treatment, randomized-block design experiment. The animals were stalled individually, offered the silages ad libitum, and in addition received 5 kg d?1 of a supplement containing 196 g kg?1 crude protein. On the basis of the data recorded during the final 28 d on treatment the animals receiving the inoculant-treated silage consumed 12 and 10% more silage dry matter and produced 2·1 and 2·3 kg d?1 more milk than those given the control and formic acid-treated silages respectively. Over the total experimental period the milk yields were 1957, 1894 and 2094 (±41·3) kg for animals receiving the control, formic acid- and inoculant-treated silages respectively. Animals offered the formic acid treated silage produced milk of significantly higher fat concentration than those given the other two silages. Total ration digestibility studies, conducted with three cows per treatment, indicated no significant differences in digestibility coefficients, nitrogen utilization or metabolizable energy concentrations of the three treatment diets. It is concluded that the higher milk yield recorded with the inoculant-treated silage, and the higher milk fat concentration with the formic acid-treated silage, over that obtained with the control silage, were due to the increases in ME intake of 5 and 16 MJ d?1 for the formic acid and inoculant-treated silages respectively.  相似文献   

9.
Our objective was to investigate Lactobacillus buchneri as a silage inoculant or probiotic on in vitro ruminal measurements of low dry‐matter whole‐crop maize silage. In vitro gas production was conducted using untreated (without inoculant) and inoculated (treated with L. buchneri CNCM I‐4323 at 1 × 105 cfu g?1 of fresh forage) maize silages (wet‐ground) incubated with three different ruminal inocula, in a 2 × 3 factorial arrangement. Ruminal fluids were collected from wethers consuming (i) untreated maize silage (RF‐U); (ii) inoculated maize silage (RF‐I); and (iii) untreated maize silage with a daily dose of L. buchneri CNCM I‐4323 administered directly into the rumen (1 × 107 cfu g?1 of supplied silage [LB‐probiotic]). Gas production was consistently higher when inoculated silage was used as the substrate of fermentation, compared to the untreated silage. When untreated silage was used as substrate, the total volatile fatty acid concentration was higher using RF‐I and LB‐probiotic inocula, compared to the RF‐U inoculum, at 9 hr and at 48 hr of fermentation. It is concluded that L. buchneri should be used as a silage inoculant rather than as a probiotic because it alters fermentation within the silo thereby improving silage quality and enabling some benefits for ruminal fermentation.  相似文献   

10.
A changeover design experiment involving thirty-six 3-month-old Friesian male calves (mean initial live weight 127 kg) was carried out to evaluate a bacterial inoculant based on a single strain of Lactobacillus plantarum (Ecosyl, ICI) as a silage additive. On 25–31 August 1988, nine silages were harvested using double-chop forage harvesters from the second regrowth of three swards, namely permanent pasture which had received 100 kg N ha?1 and perennial ryegrass which had received either 100 or 150 kg N ha?1. Herbages (mean DM and WSC concentrations 144 and 11·2 g kg?1 respectively) from each sward were treated with either no additive, formic acid (2·4 1 t?1) or the inoculant (3·3·1 t?1) and were ensiled in 126 silos of 0·8 t capacity. The only effects of the inoculant on chemical composition of the silages were a decrease in modified acid detergent fibre and an increase in endotoxin and crude and true protein concentrations. Silages were offered ad libitum and supplemented with 1·0 kg of concentrates per head daily for three periods each of 3 weeks in a partially balanced changeover design experiment. Digestibilities of the total diets were determined at the end of the experiment. For the untreated, formic acid-treated and inoculant-treated silages, silage dry matter intakes were respectively 3·58, 3·66 and 3·67 (s.e. 0·044) kg d?1, estimated metabolizable energy (ME) intakes were 46·1, 46·7 and 47·1 (s.e. 0·44) MJ d?1, energy digestibilities were 0·727, 0·727 and 0·738 (s.e. 0·0046) and organic matter digestibilities were 0·770, 0·771 and 0·788 (s.e. 0·0042). Rumen degradabilities of the silages were determined using two rumen-fistulated cows. Mean dry matter and nitrogen degradabilities for the control, formic acid-treated and inoculant-treated silages, assuming an outflow rate of 0·05 h?1, were 10·508, 0·49, 0·491 and 0·702, 0·676 and 0·729. It is concluded that the inoculant significantly increased the digestibility of the silages but did not affect dry matter or ME intake.  相似文献   

11.
Use of freshly cultured lactic acid bacteria as silage inoculants   总被引:10,自引:0,他引:10  
The use of freshly cultured lactic acid bacteria in comparison with conventional freeze-dried preparations as inoculants for grass silage was examined. Perennial ryegrass was ensiled in laboratory silos, either untreated or treated with formic acid, or a commercial freeze-dried strain of Lactobacillus plantarum , or a fresh culture of the same strain of L. plantarum , or fresh cultures of Pediococcus pentosaceous , or Lactococcus lactis alone or in combination with L. plantarum. All inoculants were applied at a rate of 106 colony-forming units g−1 fresh matter, with the mixtures containing a 1:l ratio of each species. Herbage treated with freshly cultured inoculants exhibited shorter lag times, in relation to the initiation of pH decline, than those associated with untreated or freeze-dried inoculant-treated herbages. Treatment of herbage with inoculants containing L. plantarum increased the initial speed of pH decline. In comparison with silages made with freeze-dried L. plantarum , in measurements made during the initial 14 d of ensilage, those inoculated with fresh cultures bad significantly (P<0·05) higher lactic acid concentrations and significantly (P·0.05) lower pH values. Both P. pentosaceous and L. lactis initiated a rapid fermentation, but compared to L. plantarum alone, or mixtures of L. plantarum with P. pentosaceous or L. lactis , these cultures demonstrated intermediate rates of lactic acid production and pH decline. All mature (105 d) silages were of good quality with pH values of four or less, low ammonia-N concentrations (<100gkg−1 total N) and no detectable levels of clostridia or butyric acid. Results suggested that the main advantage of freshly cultured inoculants over their freeze-dried counterparts may lie in their metabolic state when added to herbage.  相似文献   

12.
Four silages were prepared from grass treated with additives designed to produce different extents of fermentation in the silo. The additive treatments were: formic acid at 5 l t?1; a bacterial inoculant (Ecosyl, ICI plc); the inoculant plus molasses at 20 kg t?1; and a noadditive control. All silages were well preserved. Formic acid severely restricted the extent of fermentation, the concentration of lactic acid being only 50% of that seen for the other treatments, all of which were similar in lactic acid concentrations. The silages were offered ad libitum, either as the sole component of the diet or together with three supplement treatments to 16 British Friesian cows, in four 4 treatment × 4 period Latin squares with periods of 28 d duration. The supplements were: a barley-based mixture at 5 kg d?1 (B); a high-fat, high-protein product at 2 kg d?1 (FPI) and at 3 kg d ?1 (FP2); both FP treatments were given with 1 kg d?1 of molassed sugarbeet pulp. A preliminary experiment, using three lactating, rumen-cannulated cows in a 3×3 Latin square design with 28-d periods, provided information on rumen digestion when the supplements were given with a separate, non-experimental silage. In the preliminary experiment, neither of the FP treatments influenced the molar proportion of the major rumen volatile fatty acids compared with treatment B; nor were there any depressive effects of the FP treatments on silage intake compared with treatment B. In the main experiment, the intake of silage with the inoculant treatment was less than that with the other treatments, the effect being generally significant (at least P<0·05) for all three supplements. When the silages were given unsupplemented, there were differences in the concentration (P<0·001) and yield (P<0·01) of milk fat, both of which were lowest for the no-additive control and highest for the formic acid silage. When supplement B was given, the concentration and yield of milk fat were lowest for the no-additive control and the concentration and yield of milk protein were highest for the formic acid silage. For all silages both FP treatments tended to depress silage intake and reduce the concentration of fat and protein in milk compared with treatment B. Although there were clear indications of differences in nutritional characteristics between the silages, there was little evidence that the differences between silages influenced the responses to changes in the composition of the supplements.  相似文献   

13.
Data from six experiments conducted at two Agricultural Development and Advisory Service Experimental Husbandry Farms during 1980–83 were used to compare low dry matter (DM, 160 g kg-1), low water soluble carbohydrate (WSC, 15 g kg-1), non-additive treated silage with silage treated with commercial inoculants or formic acid with or without added formalin (formic acid ± formalin). Formic acid ± formalin significantly decreased silage pH and ammonia-N and significantly increased silage residual WSC compared with inoculant or untreated silage. Formic acid ± formalin significantly increased oven DM and significantly reduced DM loss during ensiling compared with untreated silage. Formic acid ± formalin treatment significantly increased both silage DM and total DM intake compared with untreated silage. Daily liveweight gains of cattle offered formic acid ± formalin were significantly higher than those given inoculant or untreated silage.
It is suggested from the results that formic acid ± formalin additives can be used successfully to prevent a clostridial fermentation developing when crops contain 15 g WSC kg-1.  相似文献   

14.
Maize was harvested at one‐third milk line (297 g kg?1 DM) stage. All inoculants were applied at 1 × 106 cfu g?1 of fresh forage. After treatment, the chopped forages were ensiled in 1·5‐L anaerobic jars. Three jars per treatment were sampled on days 2, 4, 7, 12 and 90 after ensiling, for chemical and microbiological analysis. Homofermentative LAB‐inoculated silages had lower pH and higher lactate:acetate ratio (except for Lactobacillus plantarum/Pediococcus cerevisiae and L. plantarum/Propionibacterium acidipropionici) than the control and both heterofermentative LAB‐inoculated silages. Both L. buchneri inhibited yeast growth and CO2 production during exposure of silage to air. The L. plantarum/P. cerevisiae, L. plantarum (Ecosyl) and L. plantarum/Enterococcus faecium‐inoculated silages had higher dry‐matter digestibility than the control and L. buchneri‐inoculated silages. Inoculants did not affect digestibility of neutral detergent fibre, except for L. buchneri (Biotal), organic matter nor ME content of silages. The LAB silage inoculants generally had a positive effect on maize silage characteristics in terms of lower pH and shifting fermentation toward lactate with homofermentative LAB or toward acetate with L. buchneri. The use of L. buchneri can improve the aerobic stability of maize silages by the inhibition of yeast activity.  相似文献   

15.
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.  相似文献   

16.
Two experiments describe the ensiling potential of whole‐crop forage peas (Pisum sativum) and field beans (Vicia faba). In Experiment 1, forage peas (cv. Magnus) and field beans (cv. Mayo) were harvested at 10, 12 and 14 weeks after sowing, and ensiled in 10 kg mini‐silos either untreated or treated with an inoculant (Lactobacillus plantarum). In terms of yield and ensiling potential, the optimum growth stage for harvesting forage peas occurred at 12 weeks of growth. In contrast, delaying the harvest of field beans until 14 weeks gave the highest yields of dry matter (DM) and crude protein (CP). Changes in crop maturity had little effect on the chemical composition of the fresh forages, but between‐harvest date differences were observed in the DM, ammonia‐N, CP, water‐soluble carbohydrates (WSC), acid‐detergent fibre (ADF), neutral‐detergent fibre (NDF), lactic acid and volatile fatty acids (VFA) concentrations and pH of the corresponding silages. Fermentation was improved by applying an inoculant. In Experiment 2, forage peas and field beans were harvested at 14 weeks after sowing and ensiled as round‐bale silage, either untreated or treated with an inoculant. The yields of the crops were similar, and the only difference in the chemical composition of the wilted forages was a higher CP concentration in the field beans. However, after the ensiling process was complete, the forage pea silages were found to have significantly higher DM, WSC, starch and butyric acid concentrations compared with the field bean silages, and lower ammonia‐N, CP, ADF, acetic acid and lactic acid concentrations. Inoculation was found to increase the lactic acid concentration and reduce the pH and ammonia‐N and acetic acid concentrations of the silages. Each of the silages produced in Experiment 2 was offered to six Suffolk crossbred wether lambs, aged 10 months. Voluntary DM intakes were similar on all treatments, despite the apparent digestibility of the forage pea silages being significantly higher than that of the field bean silages. Nitrogen retention was higher for lambs offered forage pea silage. Application of an inoculant was found to have a negative effect on the amount of N retained, indicating the necessity for more detailed investigations into proteolytic activity within these crops during the fermentation process.  相似文献   

17.
An experiment is described in which three silages were prepared from herbage treated with either a bacterial inoculant (Ecosyl, Imperial Chemical Industries plc) at 2-71 t?1, formic acid (850 g kg?1, Add-F, BP Chemicals International Ltd.) at 2-21 t?1, or no additive (control). The herbage (second regrowth from perennial ryegrass swards), was ensiled unwilted, and had mean dry matter (DM) and water-soluble carbohydrate concentrations at ensiling of 186 and 34-1 g kg?1 respectively. The resulting silages were all well preserved and had only minor chemical differences. Thirty lactating British Friesian cows were subjected to a 21 d standardization period and were then offered the three silages for 21 d in a randomized-block design experiment. The animals were stalled individually, offered the silages ad libitum and in addition received 5 kg d?1 of a supplement containing 198 g crude protein kg DM?1. The mean silage DM intake, milk yields and milk fat concentrations during the final 7 d on treatment were 8-44, 8-62 and 887 kg d?1; 238, 230 and 25-1 kg d?1; and 368, 400 and 366 g kg?1 for the control, formic acid- and inoculant-treated silages respectively. Following the feeding trial, six cows per treatment were subdivided to provide three animals which were offered silage alone, and three offered silage plus 5 kg d-’supplement. Rumen samples taken after 21 d on these treatments indicated no effect of the inoculant on ruman volatile fatty acid proportions, whereas the use of formic acid resulted in increases in both acetate and butyrate concentrations. The results from this study support that of the earlier work that this particular inoculant, when used at ensiling, can considerably improve animal performance over that achieved with both untreated and formic acid-treated silages.  相似文献   

18.
This study investigated the effect of a new microbial inoculant product on the composition and nutritive value of corn silage in big silo over one year that used beef cattle. Six Holstein beef steer (BW = 225 +/- 17) were allotted to 2 x 2 repeated Latin square design at two 21 days periods (adaptation, 14 days and sample collection, 7 days) for evaluation the effect of microbial inoculation on the composition and nutritive value of corn silage for beef cattle. Two treatments, forages were untreated or treated at ensiling with Lactobacillus plantarum and Propionibacterium acidipropionici silage inoculants. After 45 days from ensiling, the ration that contained 94.5 and 5, 0.2, 0.2, 0.1% of DM silage and ground barely, mineral-vitamin, dicalcium phosphate, salt, respectively, were offered for free choice consumption. Treatment with Lactobacillus plantarum and Propionibacterium acidipropionici inoculant increased daily dry matter intake and subsequently NDF, ether extract, crude protein and ash. Apparent digestibility of DM and nutrients were significantly increased by microbial inoculation. Microbial inoculation can improve the nutritive value of corn silage for beef cattle.  相似文献   

19.
A first cut of timothy, treated with water (untreated), formic acid (FA), cellulase + lactic acid bacteria (CB), cellulase + hemicellulase (CH) or cellulase + hemicellulase + a lignin-modifying enzyme (CHL), was ensiled in pilot-scale silos. Silages, except CB, were fed to four male cattle, each equipped with a rumen and duodenal cannula, in a digestibility trial designed as a 4 × 4 Latin square. The animals were fed a diet of 400 g of concentrate and 600 g of silage at a level of 70 g DM kg?1 live weight (LW0·75). All enzyme-treated silages were well-preserved with a more extensive fermentation than in FA silage. The quality of untreated silage was poorer as indicated by higher pH and ammonia-N content. The amount of effluent from enzyme-treated silages ranged from 116 to 127 g kg?1; for FA and untreated silages values were 101 g kg?1 and 80 g kg?1, respectively. Total DM losses from enzyme-treated silages were higher than from FA silage (P < 0·05). No significant differences were noticed between silages in the apparent digestibility of organic matter (OM), neutral-detergent fibre (NDF), acid-detergent fibre (ADF) or nitrogen (N). The apparent digestibility of cellulose was higher with enzyme-treated silages than with FA silage (P < 0·05). The values for microbial N flow at the duodenum were 80·0, 91·9, 80·7 and 70·5g N d?1, and for the efficiency of rumen microbial N synthesis 38·6, 47·6, 36·9 and 32·5 g N kg?1 OM apparently digested in the rumen for untreated, FA, CH and CHL silages, respectively. In the rumen the molar proportion of propionate was higher (P < 0·01) and that of butyrate lower (P < 0·01) with enzyme-treated silages when compared with FA silage. The proportion of butyrate was also lower with untreated than with other silages (P < 0·01). The rumen residence time of NDF and ADF was longer (P < 0·05) with enzyme-treated silages than with FA silage.  相似文献   

20.
A randomized block experiment involving thirty-six lactating dairy cattle was carried out to evaluate a bacterial inoculant (Grazyme Grobac, Agritech), containing bacteria, enzymes and a rumen enhancer, as a silage additive. Herbage from the primary regrowth of predominantly perennial ryegrass swards was ensiled unwilted and precision-chopped after a 51-d growth interval on 4 and 5 August. Alternate loads of herbage were ensiled either untreated (C) or treated with formic acid at a rate of 2.65 1 (t herbage)?1 (F) or the inoculant at a rate of 0.64 kg (t grass)?1 (I). The treatments were harvested using the same harvester in the rotation of I, F and C treatments. Mean dry-matter (DM), water-soluble carbohydrate and nitrate nitrogen (N) concentrations and buffering capacity of the C herbages at ensiling were 198 g kg?1, 18 2 g kg?1, 290 mg (1 juice)?1 and 379 mequiv. (kg DM)?1 respectively. For silages C, F and I pH values were 3.7, 3.8 and 3.8 and ammonia N concentrations 61, 43 and 58 g (kg total N)?1 respectively. Inoculant treatment did not alter aerobic stability of the silages, whereas formic acid treatment increased it. The silages were offered ad libitum and supplemented with 5 kg of concentrates per head daily. For treatments C, F and I silage DM intakes were 10.8, 11.2 and 10.8 (s.e. 0–33) kg d?1, milk yields 21.3, 20.9 and 20.7 (s.e. 0.52) kg d?1, fat concentrations 38.3, 40.3 and 37.2 (s.e. 0.83) g kg?1 and protein concentrations 30.8, 32.6 and 32.6 (s.e. 0.49) g kg?1 respectively. Inoculant treatment did not alter (P0.05) the digestibility coefficients of the total diets, whereas formic acid treatment decreased DM (P0.05), organic matter (P0.05), neutral detergent fibre (P0.01) and hemicellulose (P0.01) digestibilities. Formic acid treatment altered rumen fermentation patterns, whereas inoculant treatment had no effect. It is concluded that, relative to a well-preserved untreated silage, additive treatment did not alter DM intake, milk yield or fat plus protein yield. However, both additive treatments increased milk protein concentrations and formic acid treatment increased milk fat concentration relative to the well-preserved, untreated silage.  相似文献   

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