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1.
The effects of ensiling lucerne with graded inclusion of Cistus ladanifer condensed tannins (CT) on in silo fermentative parameters, in vitro organic matter digestibility (IVOMD) and on in situ rumen degradability of dry matter (DM) and crude protein (CP) were studied. Lucerne forage ( Medicago sativa subsp. sativa ) was sprayed with different solutions of C. ladanifer CT extract in 60 ml of water in order for dose 0 (control), 40 (L40), 80 (L80) and 120 (L120) g of CT per kg of lucerne DM and was ensiled in lab‐scale silos. After 35 days, the silages were analysed for chemical composition, and the in situ ruminal degradability was determined in rams. The inclusion of CT in the silages caused an important dose‐dependent reduction in soluble‐N, NH3‐N and a large increase in true protein content and N bound with neutral detergent fibre (NDF‐N), which indicates an effective proteolysis reduction during ensiling. Also, the rumen undegradable protein (RUP) increased linearly (P < 0.01) with CT inclusion. However, a linear decrease (P < 0.02) of 5%, 13% and 22% of IVOMD was observed for the silages L40, L80 and L120 respectively. The results obtained suggest that C. ladanifer CT can be used as silage additives to reduce proteolysis of high‐protein forages during ensiling. A level of CT of 40 g/kg DM seems to be the best compromise between the gains achieved by the protection of CP degradation in silo and in the rumen and the losses associated with the depression of the digestion and absorption.  相似文献   

2.
The effects of Lactobacillus plantarum (LP) and Chinese gallnut (Rhus chinensis Mill) tannin on the fermentation quality, nitrogen distribution, protein fractions and proteases activity of alfalfa (Medicago sativa) silage were studied. Additives added to alfalfa forage (approximately 40% DM) were LP (1 × 106 cfu/g FW) plus sucrose (4 g/kg FW) (LP + S), LP (1 × 106 cfu/g FW) plus commercial cellulase (0.1 g/kg FW) (LP + C) and Chinese gallnut tannin at two levels (20 and 50 g/kg DM) (TA 2% and TA 5%). The control was sprayed with the same volume of distilled water. Silage was sampled and analysed on days 1, 3, 5, 7, 14, 21, 28 and 35. The results showed that the degradation of protein to nonprotein nitrogen took place mainly during the first 3 days, while the degradation of peptides and free amino acids occurred throughout the ensiling process. All additives lowered nonprotein nitrogen and free amino acids nitrogen proportion during the ensiling. Additive TA 5% was the most effective to inhibit proteolysis among the four additives, followed by LP + S. They inhibited the activities of all three plant proteases and decreased production of nonprotein nitrogen, free amino acids and ammonia nitrogen during the ensiling process.  相似文献   

3.
Effects of formic acid, formaldehyde and two levels of tannic acid on changes in the distribution of nitrogen (N) and plant enzymatic activity during ensilage of lucerne (Medicago sativa) were studied. Lucerne [300 g dry matter (DM) kg?1 forage] silages were prepared untreated (control) and with formic acid (4 g kg?1 DM), formaldehyde (1 g kg?1 DM) and two levels of tannic acid (20 and 50 g kg?1 DM) as additives. Inhibition of proteolysis by formic acid was more effective than the other additives during the first 7 d of ensiling. Tannic acid was as effective at inhibiting production of non‐protein‐N, ammonia‐N and free amino acid‐N as formic acid and formaldehyde. However, increased concentrations of non‐protein‐N and free amino acid‐N in silage from day 1 to 35 of ensiling were less with the higher level of tannic acid than that in the control and other additive‐treated silages. Carboxypeptidase lost its activity slowly with increasing time of ensiling. At day 2, it still had 0·79 of the original activity in the control silage. After 21 d of ensiling, high levels of carboxypeptidase activity, proportionately 0·41, 0·49, 0·10, 0·35 and 0·30 of the original activity, remained in the control silage, and silages made with formic acid, formaldehyde, and low and high levels of tannic acid respectively. There were higher levels of activity of acid proteinase in formic acid‐treated silage than in the control silage until day 2 of ensilage indicating that the reduction of proteolysis by formic acid was probably due to acidifying the forage below the pH optima of plant protease. Aminopeptidase activity in all silages declined rapidly after ensiling.  相似文献   

4.
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   

5.
Sainfoin (Onobrychis viciifolia) is a tanniniferous, leguminous plant that has potentially beneficial effects on protein utilization in ruminants. As ensiling causes protein breakdown and elevated levels of buffer soluble N (BSN), we studied the distribution of N before and after ensiling sainfoin. Three varieties of sainfoin were either direct‐cut and frozen directly or wilted and frozen before later ensiling in mini‐silos with and without acidification with Promyr (PM; an acidifying commercial mixture of propionic and formic acid) and with or without polyethylene glycol (PEG). Extractable tannins (ET) and protein‐bound tannins (PBT) were measured with an HCl/butanol method in an attempt to correlate tannin levels to N fractions. The sainfoin silages showed good ensiling characteristics and had relatively high concentrations of undegraded protein. The effect of wilting on BSN levels (g/kg N) was dependent on sainfoin variety (P < 0·001). PEG increased and PM decreased the level of BSN in the silages (P < 0·001). PM treatment also produced less non‐protein N and ammonia‐N (P < 0·05) as compared with no additive. Addition of PEG to the silage increased the BSN‐proportion 1·8‐ and 2·6‐fold for both DM stages. A strong tannin‐protein binding effect is, therefore, confirmed in sainfoin. However, correlations between tannin levels (ET and PBT) and BSN were poor in the (non‐PEG) silages, indicating either that the HCl/butanol method is unsuitable for measuring tannin in silages or that qualitative attributes of tannins are more relevant than quantitative. The HCl/butanol method seems therefore not to be useful to predict degradation of protein in sainfoin silages.  相似文献   

6.
The effects of shredding forages on the density and fermentation quality of the resulting silages were studied. Lucerne (Medicago sativa L.), red clover (Trifolium pratense L.), perennial ryegrass (Lolium perenne L.) and a grass–clover mixture were harvested and wilted indoors for 1–2 days. The dry‐matter content of the forages after wilting was 192 g/kg, 192 g/kg, 237 g/kg and 214 g/kg respectively. The forages were then either unprocessed or shredded once (1×) or four (4×) times using a novel laboratory shredder and were ensiled in laboratory‐scale silos. Fermentation was terminated after either 50 or 113 days of ensiling. Density and the fermentation weight losses of the silages were recorded. Initial density of the silages was considerably increased with increased intensity of shredding (p < 0.01). The initial density (DM basis) of the 4× shredded silages ranged from 177 to 236 kg DM/m3 whereas it was 124–163 kg DM/m3 in non‐shredded silages. The 4× shredded silages had the greatest fermentation weight loss at day 1 of ensiling (p < 0.01). Overall fermentation weight loss after 113 days of ensiling was reduced in the 4× shredded silages (p < 0.01). Shredding increased L‐lactate concentration and reduced pH of the silages (p < 0.01). The NH3 concentrations were reduced by 25%–46% in 4× shredded silages and butyrate concentrations were reduced by 76%–97% in shredded silages in comparison to non‐shredded silages (p < 0.01). Shredding improved initial density and fermentation quality of silages while reducing overall fermentation weight losses.  相似文献   

7.
First and second harvests of lucerne (Medicago sativa L.), perennial ryegrass (Lolium perenne L.) and a lucerne–perennial ryegrass mixture [80 or 144 g kg?1 dry matter (DM) of ryegrass] at the first and second harvests were cut and conditioned, wilted to 500 or 700 g DM kg?1 then baled and stretch‐wrapped for silage on the same dates. Lucerne bales were denser (411 kg m?3) than bales of perennial ryegrass (331 kg m?3) (P < 0·05). After an 8‐month storage period, silage made from high DM‐content forage had a higher concentration of neutral‐detergent fibre (NDF) and was less digestible than that made from low DM‐content forage. Daily DM intakes by beef steers, when the silages of the second harvest were fed ad libitum, were 31·2, 31·2 and 22·3 g kg?1 live weight for lucerne, lucerne–perennial ryegrass mixture and perennial ryegrass silages, respectively (P < 0·01), when the herbage had been wilted to 500 g kg?1. In vivo digestibility of NDF in the lucerne–perennial ryegrass mixture silage (0·587) was significantly lower than that of perennial ryegrass silage (0·763) but higher than lucerne silage (0·518). Higher intakes of baled lucerne silage tended to offset its lower digestibility values. Lucerne–perennial ryegrass mixture silage had a higher DM and NDF digestibility than lucerne silage, indicating perhaps the presence of associative effects.  相似文献   

8.
The hypothesis was that forage species and ensiling conditions have an impact on the formation of biogenic amines and the feed choice of goats in short‐term preference trials. At ensiling, lucerne (Medicago sativa L., first cut), red clover (Trifolium pratense L., first cut) and Italian ryegrass (Lolium multiflorum Lam ., second cut) were treated differently to obtain a range of fermentation qualities. Six treatments of each forage species were prepared and included different dry‐matter concentrations, chemical and biological silage additives, and additions of soil. Silages were sampled for chemical analyses (proximate constituents, fermentation products and other volatile compounds, crude protein fractions and biogenic amines) and stored anaerobically in vacuum‐sealed plastic bags for use in preference trials (one trial for each forage species) with Saanen‐type wethers (n = 8 or 6). Each possible two‐way combination of the six silage treatments and a standard hay (n = 21 combinations) was offered for ad libitum intake for 3 hr. Data were analysed using multidimensional scaling, analysis of variance and correlation analysis between silage characteristics and dry‐matter intake (DMI). For each forage species, fermentation characteristics and crude protein fractions revealed only small differences among treatments. Although the degree of proteolysis, as measured by non‐protein nitrogen, of all silages was high, biogenic amine and butyric acid concentrations were low. The different treatments apparently had no direct influence on the formation of biogenic amines and feed choice. The preference behaviour within one forage species was strongly divergent, but DMI rankings of the three species were very similar.  相似文献   

9.
Forage choice and intake by ruminants depend on various factors. This study aimed to determine the effects of compaction, delayed sealing and aerobic exposure on forage choice and short‐term dry‐matter intake (DMI) of maize silage by goats. Whole‐crop maize (277 g/kg dry matter [DM]) in 120‐L silos was compacted at either low (194 kg DM/m3) or high (234 kg DM/m3) density, and sealed immediately at day 0 or with a delay at day 2 or day 4 post‐filling, making a total of six treatments. After ensiling for at least 175 days, silages were exposed to air for 6 days. In 2‐day intervals, silages were sampled for chemical analyses and were vacuum‐stored for use in preference trials. During the experimental phase, each possible two‐way combination of the aerobically exposed silages (days 0, 2, 4 and 6 post‐opening) of the treatments and lucerne hay was offered as free choice to goats (n = 5) for 3 hr. Exposing silages to air for >4 days post‐opening caused strong avoidance and lowest intakes. Under the conditions of the study, aerobic exposure after ensiling had a more pronounced effect on silage preference and short‐time DMI than compaction and delayed sealing. Increasing fibre fractions, a deteriorating microbial status and poor silage sensory properties, probably caused by a combination of different fermentation products, can be considered for decrease in preference.  相似文献   

10.
A laboratory-scale experiment was conducted with lucerne (Medicago sativa) to determine the effects of acid treatment on proteolysis during ensiling and during subsequent in vitro ruminal protein incubations. Lucerne [300 g dry matter (DM) kg?1 forage] was either untreated (control) or treated with sulphuric, formic or trichloroacetic acid (a protein precipitant that stops enzyme activity) at levels sufficient to adjust immediately forage pH to 4·0, then conserved as either silage or hay. Time-course data indicated that non-protein nitrogen (N) formation was 70–90% complete after 1 d of fermentation in the silo. Non-protein N concentrations (g kg?1 total N) were 177 at ensiling and increased to 567 (control), 426 (sulphuric), 398 (formic) and 263 (trichloroacetic) after 60 d of ensiling. Because non-protein N in silage treated with formic and sulphuric acids was nearly three times greater than that in silage treated with trichloroacetic acid, it is clear that the typical acid treatments only slow proteolysis and do not destroy protease activity during ensiling. The ruminal protein degradation rate of conserved forages was slower than that of fresh-cut forage that was preserved with dry ice immediately after cutting. The degradation rate of all acid-treated forages was similar, indicating a consistent effect on ruminal degradation regardless of method of preservation. There was a clear effect of acid treatment on reducing the rate and extent of ruminal degradation of protein in lucerne hay.  相似文献   

11.
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   

12.
There is a high correlation between sward height and pasture sward structure. Therefore, in tropical grasslands, taking sward height into account has been a much better strategy in rotational stocking management than considering pre‐defined days of growth. Similarly, sward height could be used to determine the moment when tropical grasses present the best ensilability parameters. This study aimed to identify the sward height at which Panicum maximum cv. Mombaça (Guinea grass) provides the highest fermentability coefficient (FC) and to define the combination of additives that best improves the chemical composition of silage. Two trials were carried out in Selvíria, MS, Brazil, from 2015 to 2016. The first year was used to identify the highest FC, and the second year was used to identify the best combination of eight additives (citrus pulp [CIP], homofermentative and heterofermentative LAB, their combinations and control). Statistical analyses were performed using SAS (p < .05), and one contrast was defined as silage with CIP vs. silage without CIP. The height of 130 cm resulted in the highest FC (31.01). Silages inoculated with CIP had better quality than silages without CIP, due to the high crude protein (8.3 vs. 7.3% DM), DM recovery (98.6 vs. 93.3% DM), low pH (3.92 vs. 4.91) and NH3‐N values (2.49 vs. 14.73% total N). Sward height is a consistent parameter for determining the time of ensiling Guinea grass, and the inclusion of CIP is necessary to raise the silage quality.  相似文献   

13.
Six dryland pastures were established at Lincoln University, Canterbury, New Zealand, in February 2002. Production and persistence of cocksfoot pastures established with subterranean, balansa, white or Caucasian clovers, and a perennial ryegrass‐white clover control and a lucerne monoculture were monitored for nine years. Total annual dry‐matter (10.0–18·5 t DM ha?1) and sown legume yields from the lucerne monoculture exceeded those from the grass‐based pastures in all but one year. The lowest lucerne yield (10 t ha?1 yr?1) occurred in Year 4, when spring snow caused ungrazed lucerne to lodge and senesce. Cocksfoot with subterranean clover was the most productive grass‐based pasture. Yields were 8·7–13·0 t DM ha?1 annually. Subterranean clover yields were 2·4–3·7 t ha?1 in six of the nine years which represented 26–32% of total annual production. In all cocksfoot‐based pastures, the contribution of sown pasture components decreased at a rate equivalent to 3·3 ± 0·05% per year (R2 = 0·83) and sown components accounted for 65% of total yield in Year 9. In contrast, sown components represented only 13% of total yield in the ryegrass‐white clover pastures in Year 9, and their contribution declined at 10·1 ± 0·9% per year (R2 = 0·94). By Year 9, 79% of the 6.6 t ha?1 produced from the ryegrass‐white clover pasture was from unsown species and 7% was dead material. For maximum production and persistence, dryland farmers on 450–780 mm yr?1 rainfall should grow lucerne or cocksfoot‐subterranean clover pastures in preference to ryegrass and white clover. Inclusion of white clover as a secondary legume component to sub clover would offer opportunities to respond to unpredictable summer rainfall after sub clover has set seed.  相似文献   

14.
Lucerne (Medicago sativa L.) requires four or more cuttings at early bud stage per growing season to optimize the amount of crude protein and digestible fibre for feeding high‐producing dairy cows. However, there is potential to generate a nutrient‐dense feed from lucerne regardless of developmental stage by harvesting its protein‐rich leaves separate from its fibrous stems. In order to determine whether fractionated lucerne can be effectively ensiled under high‐moisture conditions and be nutritionally competitive with wilted whole‐plant silage, leaf and stem fractions, harvested at three developmental stages (early bud, 10%–20% bloom and >50% bloom), were directly ensiled in mini‐silos. At day 0, 1, 3, 21 and 140 of ensiling, silages were analysed for protein and non‐protein nitrogen fractions as well as their fermentation products and carbohydrate composition. Silages from unwilted leaves and stems were more heterofermentative than wilted whole‐plant silages; their fermentation shifted from primarily lactic acid to acetic acid production after 21 days. In leaf silages, the high degree of protein degradation into non‐protein nitrogen (~55%) was most likely due to fermentation quality. Nevertheless, at 140 days of ensiling, leaf silages had 21%–25% higher (p < 0.01) available protein (peptide amino acids, soluble and insoluble protein) content than wilted whole‐plant silages, regardless of developmental stage. Achievement of a more rapid pH decline and improved fractionation may further increase the nutritional value of leaf silages.  相似文献   

15.
The objective of this study was to determine the effect of diets containing pearl millet silage ammoniated with urea on the intake, digestibility, production performance, and nitrogen metabolism of lambs. Thirty‐two uncastrated mixed‐breed lambs at 4 to 5 months of age, with an average initial body weight of 17.39 ± 2.16 kg, were distributed into four treatments in a randomized block experimental design with eight replicates. Experimental diets consisted of pearl millet silage ammoniated with urea during ensiling at the levels of 0, 20, 40, and 60 g/kg dry matter (DM). Increasing urea levels in the pearl millet silage led to a linear decrease (p < .05) in the intakes of DM, organic matter, and total digestible nutrients by the lambs. Total and average daily weight gains decreased linearly (p < .05) with the addition of urea to the silage. Intake and digestibility of crude protein, nitrogen intake, urine urea nitrogen, plasma urea nitrogen, microbial synthesis, and microbial efficiency had a quadratic response (p < .05) to the urea levels in the silage. Pearl millet silage ammoniated with urea reduces dry‐matter intake and daily weight gain in lambs. Urea is not recommended for use in the ensiling of pearl millet.  相似文献   

16.
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   

17.
Silages were prepared in late September from a mixed crop of perennial ryegrass and white clover with low dry matter and high nitrogen content. Six different treatments were used during ensiling; addition of either molassed sugar beet pulp or rolled barley, at 50 kg and 25 kg (t fresh grass)?1, formic acid at 51 t?1 and no additive (control). All silages were well fermented with low levels of ammonia and pH. The addition of rolled barley or sugar beet pulp increased the dry matter content of the silages incrementally and appeared to assist the retention of nitrogen in the silage. Dry matter intakes of silages with 50 kg of barley or sugar beet pulp tonne?1 were similar to the control silage when fed to wether sheep but at 25 kg t?1, dry matter intake increased by 0·15 with barley and 0·04 with sugar beet pulp compared to the control. The digestibility of dry matter (DM) and organic matter (OM) were significantly higher than the control for silages treated with formic acid or high levels of barley and sugar beet pulp whereas neutral-detergent fibre (NDF) digestibility did not appear to be significantly affected. All treated silages had a significantly higher metabolizable energy (ME) content than the control, and additions of barley or sugar beet increased the ME content. The ME intakes of all treated silages were also significantly greater than those of the control, and the formic acid-treated and low barley silages were the highest. This appeared to be associated with significantly higher energy digestibility and DM intake. Addition of rolled barley during ensilage resulted in greater nitrogen intake, availability and retention compared to additions of sugar beet pulp. The higher retention with barley silages was associated with a significantly lower proportional loss of absorbed nitrogen in urine, which indicated a more efficient utilization of nitrogen. These differences require further study to determine the mechanisms involved in the interactions between the energy source and herbage protein, both during fermentation and in the rumen.  相似文献   

18.
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.  相似文献   

19.
This study was conducted to evaluate the effects of Lactobacillus plantarum, molasses and/or ethanol on fermentation quality and aerobic stability of total mixed ration (TMR) silage, which is widely used in dairy cow diets at mid‐to‐late lactation in Tibet. TMR was treated with ethanol (E), molasses (M), Lactobacillus plantarum(L), ethanol+molasses (EM), ethanol+Lactobacillus plantarum (EL) plus control. After 45 d of ensiling, inoculant significantly (P < 0·05) increased lactic acid (LA) concentration and decreased pH, ammonia nitrogen (AN) concentration, and aerobic bacterial and yeast counts, compared to control. After the first 3 d of aerobic exposure, LA for silages without ethanol started to decrease, while LA for E silages almost remained unchanged till the end of the aerobic exposure period. The pH in TMR silages without ethanol gradually increased, while that for E and EL remained about 4·60 and 4·00, respectively, and EL showed the lowest pH among six silages over the course of aerobic exposure. Aerobic bacterial counts in control, M and EM silages were significantly higher (P < 0·05) than those in E, L and EL, and yeast counts in E and EL silages were significantly lower (P < 0·05) than those in other silages after 9 d of aerobic exposure. The results suggest that inoculation with L. plantarum was more effective in altering fermentation characteristics than adding molasses, while ethanol showed a potential to protect TMR silages from pH increase and delayed the growth of aerobic bacteria and yeast either alone or in combination with L. plantarum.  相似文献   

20.
A factorial experiment was carried out to evaluate the effects of level of nitrogen (N) application to grassland and subsequent treatment of the herbage at ensiling with formic acid on the rate of silage fermentation, dry-matter (DM) recovery, aerobic stability and effluent production. Herbage from the primary regrowth of predominantly perennial ryegrass swards received either 72 (LN), 126 (MN) or 180 (HN) kg N ha?1. The herbages were harvested and yield estimated after a 50-day regrowth interval. After storage for 24 h in polythene bags, the herbages were ensiled, unwilled, in laboratory silos (6 kg capacity) either untreated (UT) or treated with formic acid (F) at 3 ml (kg herbage)?1. Three silos per treatment were opened and sampled on days 1, 3, 6, 15, 50 and 105 after ensiling. The mean herbage yields for the LN, MN and HN swards were 5.2, 6.3 and 6.2 (s.e. = 0.27) t DM ha?1 and there was no carryover effect of nitrogen treatment on the yield of a subsequent 22-day regrowth harvested on 2 September. As level of fertilizer N application increased, concentrations in the herbage at mowing of crude protein, nitrate and ash increased, DM decreased and water-soluble carbohydrate and in vitro DM digestibility remained unchanged. Increasing the rate of N fertilizer to the sward resulted in higher silage pH (P< 0.001) and ammonia N concentrations (P <0.001) at each time of sampling. Increasing the rate of fertilizer N increased effluent output (P < 0.001) and DM recovery (P < 0.001). Aerobic stability was improved (P <0.001) by use of high rates of N fertilizer application. Formic acid treatment restricted fermentation and increased effluent output (P <0.001) but had no effect (P > 0.05) on DM recovery. It is concluded that the rate and extent of pH decline was reduced with increasing N application, associated with increased buffering capacity and decreased DM concentrations of the herbage at ensiling. However, increasing the level of N fertilizer applied increased DM recovery and effluent output, and improved aerobic stability of the resulting silages.  相似文献   

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