The effect of addition of sugar and inoculation with two commercial inoculants on the fermentation of lucerne silage in laboratory silos

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.     

The effect of cereal incorporation on the fermentation of spring-and autumn-cut silages in laboratory silos

The effect of adding ground oats and barley on the ensiling characteristics of autumn-and spring-harvested ryegrass was studied in laboratory scale silos.
The addition of oats or barley at rates of 13 or 53 kg t⁻¹ of grass significantly improved the fermentation of late autumn ryegrass silage in the first year. Ammonia N levels were reduced from over 20% of total N to 11% or less. Similar addition to autumn-cut ryegrass higher in soluble carbohydrate content in the second year also significantly reduced pH and ammonia levels but all silages were well fermented. Addition of cereals to spring-cut ryegrass containing over 20% soluble carbohydrate had no effect on fermentation. Cereal addition increased silage DM and decreased silage fibre content in all experiments.
The results are discussed in relation to the potential advantage of cereal addition in the ensiling of grass crops.     

Effect of herbage water-soluble carbohydrate content and weather conditions at ensilage on the fermentation of grass silages made on commercial farms

A total of 1009 samples of silage made in bunker silos on commercial farms between 1972 and 1978 was analysed to investigate the effect of herbage water-soluble carbohydrate content (WSC) and weather conditions at ensilage on fermentation as measured by ammonia-N concentration and pH of first-cut grass silages.
Silage dry matter (DM) content had the major effect on fermentation. Factors influencing silage DM were rainfall and hours of sunshine during silage making, and DM content of the grass cut. WSC content of herbage ensiled also had a significant effect on subsequent fermentation. The major influences on herbage WSC were hours of sunshine and rainfall during the growing season.
The effect of chemical additives, albeit at poorly defined and often inadequate rates, was small in comparison to that of silage DM.
The minimum DM necessary to produce well-fermented silage without additive was approximately 260 g kg⁻¹. Use of formic acid significantly reduced this requirement to 240 g kg⁻¹ and to 252 g kg⁻¹ for sulphuric add + formalin. The results indicate that the minimum herbage WSC necessary to prevent a clostridial fermentation developing in silage with a DM content of 230 g kg⁻¹ is approximately 37 g kg⁻¹ without additive and 30 g kg⁻¹ with formic acid.
It is concluded that on commercial farms, weather conditions i.e. amount of rainfall and sunshine prior to and at ensilage, have a greater effect on subsequent silage fermentation than additive use.     

The microbiological and chemical composition of silage over the course of fermentation in round bales relative to that of silage made from unchopped and precision-chopped herbage in laboratory silos

The composition of baled silage frequently differs from that of comparable conventional silage. A factorial experiment was conducted with three wilting treatments (0, 24 or 48 h) × three ensiling systems [unchopped grass in bales, unchopped grass in laboratory silos (LS), precision-chopped grass in LS] × six stages of ensiling to (i) confirm that the fermentation of unchopped grass in LS could be used as an adequate model for baled silage fermentation, (ii) quantify the differences between baled silage and silage made from precision-chopped herbage across a range of dry-matter contents and (c) quantify the fermentation dynamics within the various treatments. The onset of fermentation as evidenced by the accumulation of fermentation products and the decline in pH were slower ( P  < 0·05) in baled silage compared with silage made from precision-chopped herbage. Furthermore the pH ( P  < 0·001) and overall concentration of fermentation acids ( P  < 0·01) were lower while ammonia-N concentration was generally higher in baled silage, making it more conducive to the activities of Clostridia , Enterobacteria and yeast. Numbers of Enterobacteria were higher ( P  < 0·001) in baled silage in the early stages of ensilage and persisted in baled silage at the end of the storage period. The implications of a slower onset of fermentation in baled herbage are greater in farm practice, as the fermentation would be further restricted by a more extensive wilting of the herbage prior to ensiling.     

Cell wall degrading enzymes for silage. 1. The fermentation of enzyme-treated ryegrass in laboratory silos

The effects of two commercial cellulase/hemicellulase enzymes derived from Trichoderma reesei on silage fermentation were investigated in three laboratory-scale experiments. In Experiment 1, perennial ryegrass ( Lolium perenne ) was treated with enzyme A at the rates of 0, 0·125, 0·250, 0·500 and 0·750 cm³ kg^-1. In Experiment 2, Italian ryegrass ( Lolium multiflorum ) was treated with the same enzyme at the rates of 0, 0·250 and 0·500 cm³ kg^-1 and with 85% formic acid (3·5 cm³ kg^-1). In Experiment 3, perennial ryegrass was ensiled untreated, with enzyme A (0·250 and 0·500 cm³ kg^-1) and with 0·200 and 0·400 cm³ kg^-1 enzyme B which also contained glucose oxidase. All silages were well preserved. In general enzyme treatment reduced pH and the contents of ammonia nitrogen, neutral detergent fibre and acid detergent fibre, whereas the contents of water-soluble carbohydrates, acetic acid, lactic acid and ethanol were increased.     

Response of herbage regrowth and water-soluble carbohydrate concentration of ryegrass species to defoliation practices when grown in a Mediterranean environment

Three experiments were conducted to determine the association between leaf number per tiller at defoliation, water‐soluble carbohydrate (WSC) concentration and herbage mass of juvenile ryegrass plants when grown in a Mediterranean environment. Seedlings of ryegrass were grown in nursery pots arranged side‐by‐side and located outside in the open‐air to simulate a mini‐sward in Experiments 1 and 2, and a mixture of annual ryegrass and subterranean clover (Trifolium subterraneum L.) was grown in a small plot field study in Experiment 3. Swards were defoliated mechanically with the onset of defoliation commencing within 28 d of germination. Frequency of defoliation ranged from one to nine leaves per tiller, whilst defoliation height ranged from 30 mm of pseudostem height that removed all leaf laminae in Experiment 1, to 50 mm of pseudostem height with some leaf laminae remaining post‐defoliation in Experiments 2 and 3. A positive relationship between herbage mass of ryegrass, WSC concentration and leaf number per tiller at defoliation was demonstrated in all experiments. In Experiment 1, the herbage mass of leaf, pseudostem and roots of tillers defoliated at one leaf per tiller was reduced to 0·10, 0·09 and 0·06 of those tillers defoliated less frequently at six leaves per tiller. However, the reduction in herbage mass from frequent defoliation was less severe in Experiment 2 and coincided with a 0·20 reduction in WSC concentration of pseudostem compared with 0·80 measured during Experiment 1. In Experiment 3, the highest harvested herbage mass of ryegrass occurred when defoliation was nine leaves per tiller. Although the harvested herbage from this sward contained senescent herbage, the in vitro dry‐matter digestibility of the harvested herbage did not differ significantly compared with the remaining treatments that had been defoliated more frequently. Leaf numbers of newly germinated ryegrass tillers in a Mediterranean environment were positively associated with WSC concentration of pseudostem and herbage mass. A minimum period of two to three leaf appearances was required to restore WSC concentrations to levels measured prior to defoliation thereby avoiding a significant reduction in herbage mass. However, maximum herbage mass of a mixed sward containing ryegrass and subterranean clover was achieved when defoliation was delayed to nine leaves per tiller.     

The effect of drying temperature on in vitro dry-matter digestibility and water-soluble carbohydrate content of perennial ryegrass varieties

In official forage grass variety trials in the UK, herbage samples are dried at 100°C or more to facilitate quick drying of the large numbers of samples that are currently needed. When assessing herbage quality, however, 80°C has been recommended as the highest temperature that can be used during drying without serious deterioration. Herbage from six perennial ryegrass varieties, which were known to show a range of variation in in vitro concentration of digestible dry matter (DMD) and water-soluble carbohydrate concentration (WSC) during the vegetative phase of growth, was dried in an oven with forced ventilation at 100°C and at 80°C before analysis. Mean DMD over all varieties was slightly lower [6 g kg⁻¹ dry matter (DM)] and mean WSC over all varieties was considerably lower (24 g kg⁻¹ DM) at 100°C. Varieties differed in mean DMD over both drying temperatures by 37 g kg⁻¹ DM and in mean WSC by 63 g kg⁻¹ DM. There was, however, no significant interaction between variety and drying temperature for either DMD or WSC. Although drying at the higher temperature underestimated both DMD and WSC, it did not significantly alter the ranking of varieties or the range among them.     

The effect of an acid salt-type additive on the fermentation of grass silages made in bunker silos on commercial dairy farms in Wales

The fermentation characteristics and chemical composition of 57 first-cut and 30 second-cut samples of grass silages, made in bunker silos on commercial dairy farms in Wales in 1990, and treated with a nominal 61 t⁻¹ of an acid salt-type additive at ensilage, is described. Typical chemical composition of grass cut for ensilage was 156 g kg⁻¹ dry matter (DM) and 28 g kg⁻¹ water soluble carbohydrate (WSC), with 181 g (kg DM) ⁻¹ crude protein (CP) and 232 g (kg DM) ⁻¹ modified acid detergent fibre (MADF). The effect of additive use was to produce silages with DM 230 g kg⁻¹ pH 3·93, ammonia N 70 g kg⁻¹ total N, with residual WSC 35 g (kg DM) ⁻¹, lactic acid 83 g (kg DM) ⁻¹, total acids 118 g (kg DM) ⁻¹ and butyric acid 0·7 g (kg DM) ⁻¹. No significant differences were found between first- and second-cut silages. Silage fermentation was restricted (i.e. lactic acid less than 60 g kg DM⁻¹) in only 20% of the samples.
It is suggested that on commercial farms the application rate achieved may be insufficient to produce a restricted fermentation.     

Effects of ethanol,molasses and Lactobacillus plantarum on fermentation characteristics and aerobic stability of total mixed ration silages

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.     

The effect of drainage on herbage growth and soil development

The effects of drainage on the yield of perennial ryegrass ( Lolium perenne ) swards grown for silage, and on soil development under grassland, were studied between 1982 and 1985.
Over the 4 years of the experiment, drainage resulted in a mean increase in herbage production of 1-5 t dry matter (DM) ha⁻¹, 16% above the yield recorded on the undrained site. Drainage also led to increased herbage nitrogen contents at every cut except one, so that total nitrogen recovery was increased by an average of 24-8 kg N ha⁻¹ (15%) when drainage was installed. These total differences were mainly due to differences that were present at the first cut taken in June each year; drainage led to an average 24% increase in yield, and an average 27% increase in nitrogen recovery at the first cut.
Detailed sward measurements taken in 1985 endeavoured to explain these differences; drainage increased depth to free water over winter, enabling increased root efficiency and nitrogen availability, greater tillering and more rapid leaf extension in early spring. There was some suggestion that drainage also led to an improved topsoil structure in terms of improved aggregation and aeration. This is important for long-term soil development as well as short-term herbage yield.     

The effect of harvest date and inoculation on the yield, fermentation characteristics and feeding value of kale silage

Using new harvesting and ensiling technologies, it is now possible to ensile kale ( Brassica oleracea ) successfully. However, there is little information available regarding the optimum time for harvest. The aim of this 2-year study was to compare the yield, fermentation characteristics and feeding value of kale harvested at different stages of growth, and ensiled with and without a bacterial inoculant. During Year 1 the crop was harvested after 15, 18 and 20 weeks of growth. The yield at each harvest was similar, but as the crop matured the crude protein (CP) concentration and buffering capacity decreased significantly, and there was a marked increase in the water-soluble carbohydrate (WSC) concentration. During Year 2 the crop was harvested at 14 and 17 weeks of growth. Again, the stage of maturity did not affect yield and, on this occasion, the chemical composition of the crop was unaffected by harvest date. However, the WSC and CP concentrations of the crop were lower in Year 2 than in Year 1, possibly as a result of differences in fertilizer regime. Each of the silages produced in Year 2 was offered to six Suffolk cross wether lambs, aged 10 months, to measure voluntary intake, in vivo digestibility and nitrogen retention. Neither harvesting date nor the use of an inoculant affected voluntary intake or nitrogen retention by the lambs. However, in vivo digestibility was higher in the kale silage harvested after 14 weeks of growth and when an inoculant was applied. The results obtained suggest that harvesting kale after 14 weeks of growth can produce highly digestible silage with a high CP concentration. Although delaying harvest until 18 weeks of growth will probably result in a decrease in the CP concentration of the crop, it should also lead to an increase in the WSC concentration of the crop, ensuring a more reliable fermentation.     

Effects of maltogenic amylase from Lactobacillus plantarum on retrogradation of bread

Maltogenic amylase originated from Lactobacillus plantarum (LpMA) was studied to investigate its applicability as an antistaling enzyme. The differential scanning calorimetry (DSC) results demonstrated that the bread treated with purified LpMA exhibited a retrogradation peak that was 65% that of the control bread. Then, for the purpose of practically using L. plantarum as an antistaling agent, the expression of LpMA in L. plantarum was enhanced by growth on a modified medium; the LpMA expression of L. plantarum grown on De Man, Rogosa and Sharpe (MRS) medium supplemented with an additional 6% glucose was 54 times higher than that of L. plantarum grown on the original MRS medium. The side chain length distribution analysis showed that the cell extract of L. plantarum (CELP) tended to prefer to hydrolyzes the long side chains of amylopectin (>30). During storage for 9 days at 4 °C, the bread treated with CELP exhibited a 25% slower retrogradation rate and 63% lower hardness relative to the control bread, indicating that the CELP is a potential candidate for use as an antistaling agent.     

The effects of incorporating sugar-beet pulp with herbage at ensiling on silage fermentation, effluent output and in-silo losses

Three studies were undertaken with the aim of examining in-silo losses associated with ensiling mixtures of beet pulp and herbage. In Experiment 1, first-regrowth perennial ryegrass was ensiled untreated or mixed with either 40 or 120 kg unmolassed beet pulp t^?1 fresh grass prior to ensiling. In each of Experiments 2 and 3, second-regrowth ryegrass was ensiled untreated or mixed with either 40, 80 or 120 kg unmolassed beet pulp t^?1 fresh grass prior to ensiling. Dry-matter concentrations of herbage ensiled in Experiments 1, 2 and 3 were 141, 157 and 139 g kg^?1 respectively. Time-course studies indicated a more rapid fermentation with the untreated silages. Ensiling beet pulp with herbage resulted in significant improvements in silage fermentation, reflected in reductions in silage pH and ammonia nitrogen concentrations, with these effects being pronounced at beet pulp inclusion in excess of 80kg t^?1. Beet pulp inclusion increased the dry-matter concentrations of the resulting silages while reducing crude protein, modified acid detergent fibre and gross energy concentrations. In Experiment 1 beet pulp retained 1·62 and 1·641 effluent kg^?1 at the 40 and 120kg t^?1 application rates respectively. In Experiments 2 and 3, effluent retentions were 1·40, 1·29 and 0·93 1 kg^?1 and 2·87, 2·19 and 1·781 kg^?1 at the 40, 80 and 120kg t^?1 beet pulp inclusion rates respectively. In each of Experiments 1 and 3, in-silo losses were reduced with increasing level of beet pulp inclusion, while in Experiment 2 in-silo losses were relatively unaffected by treatment. Nutrient losses in effluent were reduced by the inclusion of beet pulp in all three experiments, while nutrient losses in surface waste and invisible nutrient losses tended to increase with higher levels of beet pulp inclusion. It is concluded that the inclusion of beet pulp with herbage at ensiling can result in an improved silage fermentation and a reduction in in-silo losses, while at the same time retaining considerable quantities of effluent within the silo. However, with herbage dry-matter concentrations below 160gkg^?1, beet pulp inclusion in excess of 120 kg t^?1 herbage would be required to eliminate effluent production totally.     

Differences in winter-hardening between phenotypes of Lolium perenne with contrasting water-soluble carbohydrate concentrations

Carbohydrates are essential for the winter-hardening of temperate grasses, affecting both rate of hardening and level of frost hardiness. The rate and extent of winter-hardening of contrasting phenotypes of two Lolium perenne cultivars targeted for differences in water-soluble carbohydrates concentration were quantified under controlled hardening conditions and standardized freeze testing. The phenotype with the lowest water-soluble carbohydrates concentration had a lower rate of hardening and tolerated less frost than the other phenotypes but the effect of water-soluble carbohydrate concentrations on the hardening processes levelled off at increasing water-soluble carbohydrate concentrations, indicating a threshold. Contrasting responses to freezing were found for survival and for potential for tillering and regrowth. Mortality was little affected by the higher test temperatures, while tillering was negatively affected, even at −5°C. Compensatory regrowth of tillers surviving the lower test temperatures partially compensated for the effects of loss of tillers on regrowth. The hardiest phenotypes had a rapid lowering of LT₅₀ during the first 3 d (−1·65°C d⁻¹), acquiring LT₅₀ values at −15°C or below in 10 d. The hypothesis that rate and maximum level of hardening increase with water-soluble carbohydrates concentrations in stubble is supported by the results.     

The effect of herbage allowance upon the herbage intake and performance of suckler cows and calves

Twenty-four Hereford × Friesian cows and their South Devon cross calves were allocated to three herbage allowances allotted daily for three periods of 8 weeks in a Latin square design. The daily allowances were 17, 34 and 51 g dry matter per kg cow plus calf live weight. Milk production was depressed by 0·2 and 1·2 kg d^-1 at the medium and low allowances. The corresponding falls in liveweight gain were for cows 0·26 and 0·25, and for calves 0·27 and 0·24 kg d^-1. Residual sward height after grazing gave a better indication of the animals' reaction to sward conditions and the management imposed than actual herbage allowance. The quantity per unit area and the composition of material present were important factors influencing intake. Calves were unable to compete with their dams to maintain herbage intake at the lower allowances and therefore are likely to benefit from additional feeding or creep grazing when residual sward height falls below 6cm for periods in excess of 1–2 weeks.     

Influence of harvest date of primary growth on microbial flora of grass herbages and haylage, and on fermentation and aerobic stability of haylage conserved in laboratory silos

The influence of harvest date of the primary growth of grass herbages on the microbial flora of herbage pre-conservation and haylage post-conservation was studied along with fermentation variables and aerobic stability of haylage. The primary growths of two grass swards, one intensely (Int) and one extensively (Ext) managed, were cut at three different harvest dates (May, June, August) and ensiled in laboratory silos for 120 d. Later harvest dates resulted in increased counts of yeast, mould and enterobacteria in the pre-conserved herbage ( P  <   0·001). Counts of lactic acid bacteria (LAB) ( P  <   0·001) and number of mould species ( P  <   0·001) were highest in the pre-conserved herbage harvested in August. Later harvest dates resulted in higher yeast ( P  <   0·001) and LAB ( P  <   0·001) counts in the haylage while counts of enterobacteria decreased ( P  <   0·001). Clostridial spore counts were unaffected by harvest date both in herbage and haylage. The haylage harvested in August had the lowest pH and the lowest concentration of ethanol but the concentration of lactic acid was in general low. Aerobic stability was longer ( P  <   0·01) for haylage from herbage harvested in August compared with haylage from herbage harvested in May and June. Sward type had less influence than harvest date on microbial variables in herbage and haylage and on fermentation variables of haylage, and did not influence the aerobic stability of haylage.     

The effects of incorporating sugar beet pulp with forage maize at ensiling on silage fermentation and effluent output using drum silos

The effects of incorporating sugar beet pulp with forage maize at ensiling on silage fermentation, effluent output and pollution potential of the effluent was investigated using 200-litre drum silos. A forage maize crop (Zea mais) was harvested on four different dates, generating four different stages of maturity [dry-matter (DM) content 154–235 g kg⁻¹ DM], and molassed sugar beet pulp (MSBP) was added at five different rates (0, 2, 7, 13, 18 kg MSBP 100 kg⁻¹ fresh maize crop). A total of fourteen treatments (each replicated three times) were evaluated. The chemical analysis of the maize silages and the mixtures produced showed that MSBP addition increased DM, ash, neutral cellulase gaminase digestibility (NCGD) and metabolizable energy (ME) contents of the mixture significantly (P < 0·01) for all harvesting dates except for harvest date 1. Silage fermentation in terms of final pH was unaffected by MSBP addition, although lactic acid concentration of the effluent tended to increase with increased MSBP addition. When no MSBP was included, large volumes of effluent were produced, ranging from 200 g kg⁻¹ to 100 g kg⁻¹. MSBP addition significantly (P < 0·01) decreased effluent production except for the driest material. A curvilinear equation was fitted to predict effluent production from DM of the forage maize and pressure applied to the sample (adjusted r²=0·95). In addition, a curvilinear equation was fitted to predict the MSBP addition rate required to prevent effluent production (adjusted r²=0·65). For harvest dates 1, 2 and 3, the biological oxygen demand for 5 days (BOD₅) and the chemical oxygen demand (COD) concentration of the effluent were significantly increased (P < 0·05) with increased levels of MSBP addition. However, the pollution potential per kg of material ensiled was significantly reduced (P < 0·05) with increased MSBP addition, since less effluent was produced. The experiment indicates that ensiling low DM silages with appropriate levels of MSBP produces nutritionally valuable silages with reduced pollution potential.     

The effect of some pre-treatments on proteolysis during the ensiling of herbage

Two experiments were carried out to examine the nitrogenous changes occurring in herbage during harvesting and ensiling. In the first, ryegrass-clover was wilted rapidly in the laboratory (6 h) and in the field under good (48 h) and poor (48 h and 144 h) weather conditions. Protein breakdown and ammonia formation were negligible in herbage wilted rapidly and it was only when the crop was exposed to a prolonged wilt in humid conditions that appreciable proteolysis occurred. In the second experiment ryegrass-clover was ensiled in laboratory silos after treatment with varying levels of formic and sulphuric acids. An additional treatment included herbage inoculated with a mixture of lactic acid bacteria and glucose. The silos were opened after 4 and 50 d and samples were analysed for protein-N, ammonia-N, water-soluble carbohydrates and organic acids. There was a high negative correlation between level of addition of either acid and the degree of proteolysis and deamination. Even at the highest levels of formic acid (7·7 g per kg) and sulphuric acid (4·0 g per kg) additions, however, about 45% of the original herbage protein was degraded after 50 d in the silo. The inoculum treatment was also effective in reducing proteolysis, the effect after 50 d being comparable with formic acid applied at a rate of 4·1 g per kg.     

茶叶籽乳杆菌的分离鉴定及其发酵作用特性研究

为阐明茶叶籽水浆发酵微生物种类及其在发酵过程中的作用特性,对发酵5βh的茶叶籽水浆发酵液进行微生物分离与提纯,从中分离纯化出1株菌株。经形态观察、16βS rDNA及pheS基因测序与比对、系统发育树的构建与分析,确定该菌株为植物乳杆菌（Lactobacillus plantarum ssp. Plantarum）;命名该菌株为茶叶籽乳杆菌（Lactobacillus plantarum ssp. plantarum JJZ21）,菌种保藏号为CCTCC M 2016471。在茶叶籽水浆发酵过程中,发酵液中茶叶籽乳杆菌的数量在5βh之后逐渐快速增加,至12~15βh之间达到最大值,之后又逐渐降低,至22βh后,逐渐趋于稳定。伴随茶叶籽乳杆菌数量的增加,发酵液中的干物质含量、可溶性糖含量、可溶性蛋白含量及其pH均明显下降,呈极显著（P<0.01）负相关性。茶叶籽乳杆菌通过消耗发酵液中的可溶性糖及可溶性蛋白等物质,向发酵液中分泌乳酸等酸性有机物,导致发酵液pH逐渐降低,为发酵液中的油脂体上浮以及茶叶籽水浆发酵分层现象发生奠定了基础。     

Re‐ensiling and inoculant application with Lactobacillus plantarum and Propionibacterium acidipropionici on sorghum silages

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.