Final Silage Research Articles

Effect of Inoculants and Sealing Delay on the Fermentation Quality of Early Harvested Wheat Forage

Winter cereal silages can suffer from an inadequate fermentative path which can lead to aerobic instability. We evaluate the pre-ensiled conditions influencing the final fermentative quality and its aerobic stability. We studied the use of hetero/homofermentative inoculants on two early-harvest wheat samples (312 and 348 g/kg of dry matter—DM levels) undergoing three ensiling delays. The fermentative profiles were evaluated during the first ten d of ensiling, at 60 d and after 7 and 14 d of aerobic exposure. Aerobic stability was recorded during fourteen d after the silo opening. Significant (p < 0.05) differences of the final fermentative profile were related mainly to DM levels at harvest, while the use of the inoculant affected only the acetic acid significantly. Finally, the sealing delay did not significantly affect the silage fermentative profile. The overall aerobic stability was 59.2 ± 23.6 h, and cumulative temperatures were lower than 438 for seven d of aerobic exposure and higher than 1526 for 14 d. Although the homofermentative inoculants reduced the counts of yeasts in the final silage for the earlier harvested wheat, the other samples showed yeasts counts of ~4.9 Log10 colony-forming units/g, with the presence of spoilage fungi (Pichia and Geotricum).

Exploring the Epiphytic Microbial Community Structure of Forage Crops: Their Adaptation and Contribution to the Fermentation Quality of Forage Sorghum during Ensiling.

In this study, the effects of epiphytic microbiota from different forages on the fermentation characteristics and microbial community structure of forage sorghum silage were investigated. The gamma irradiated sterilized forage sorghum was treated through sterile water, epiphytic microbiota of forage sorghum (FSm), Sudan grass (SDm), Napier grass (NPm), and maize (MZm). NPm and SDm inoculated silages showed similar pH value and lactic acid (LA) and acetic acid (AA) contents at day 3 and 60 of ensiling. The final silage of FSm and MZm showed lower (p < 0.05) pH and AA content and a higher LA content compared to the NPm and SDm silages. Bacterial species from the Weisella genus were predominantly present in FSm, NPm, and SDm, while Lactococcus dominated the MZm silage during early ensiling. Lactobacillus was predominant in all inoculated terminal silages. Overall, the four inoculated microbiota decreased the pH value of silage and were dominated by lactic acid bacteria (LAB); however, the NPm and SDm treatments resulted in comparatively higher AA contents which could have an inhibitory effect on the secondary fermentation developed by the yeast and enhanced the aerobic stability of forage sorghum silage.

Fermentation Quality and Bacterial Ecology of Grass Silage Modulated by Additive Treatments, Extent of Compaction and Soil Contamination

New technologies related to the identification of bacterial communities in fresh forage and silage may give valuable detailed information on the best practices to produce animal feeds. The objective was to evaluate how management conditions during silage making manipulate the profile of bacterial communities and fermentation quality of grass silages. Silages were prepared from mixed timothy and meadow fescue grass using two compaction levels. As an additional treatment the grass was contaminated with soil and feces prior to tight compaction. Four additive treatments with different modes of action were applied: control without additive, formic acid-based additive, homofermentative lactic acid bacteria and salt-based additive. After 93 days the silos were opened, samples were taken and routinely analyzed. DNA extraction was carried out and PCR amplification of the bacterial 16S rRNA gene V4 region was performed using universal primers. The silage pH was higher for loose than tight compaction and higher for non-contaminated than for contaminated silages. Great shift was observed in bacterial profiles from fresh material towards silage. Lactobacillus genus was barely found on the relative abundance of fresh grass but became predominant in the final silage along with Sphingomonas genus. Use of additives improved fermentation quality and modified the bacterial profiles of grass ensiled under different management conditions.

Effect of Different Regions and Ensiling Periods on Fermentation Quality and the Bacterial Community of Whole-Plant Maize Silage.

This study aimed to explore the changes in the microbial community on the silage material surface and during the ensiling process of whole-plant maize in different regions. Whole-plant maize silages were sampled in Ziyun, Guanling, and Weinning counties within warm and humid climate areas in southern China. Silages were sampled at 0, 2, 5, 10, 20, and 45 days during ensiling. The nutritional components, fermentation properties, and microbiomes were examined to evaluate the influence of sampling area and fermentation time on the quality of silage. The results showed that the pH values of all silages significantly decreased (<4.2 at ensiling day 2) during fermentation and all silages achieved satisfactory fermentation at 45 days. Butyric acid was not detected during ensiling, and the contents of acetic acid and ammonia nitrogen in the final silages were below 6 g/kg DM and 50 g/kg total nitrogen, respectively. Weissella was the dominant epiphytic bacteria of raw material in Ziyun and Weinning, while Lactobacillus was prevalent in Guanling. Lactobacillus dominated the ensiling process, and its abundance significantly increased with increasing fermentation time in the three groups. Lactobacillus was negatively correlated with pH of all silages (p < 0.05) and positively correlated with lactic acid, propionic acid and acetic acid (p < 0.05). Furthermore, the bacterial community was significantly correlated with environmental factors. Altitude had a highly positive correlation with the abundance of Stenotrophomonas, Chryseobacterium, and Massilia (p < 0.01), while precipitation was negatively correlated with these bacteria. The humidity and average temperature significantly influenced the Lactobacillus and Weissella abundances of fresh whole-plant maize. During the ensiling process, the silages from three regions had similar bacterial dynamic changes, and the Lactobacillus formed and maintained good fermentation characteristics in whole-plant maize silage.

Bacterial Succession Pattern during the Fermentation Process in Whole-Plant Corn Silage Processed in Different Geographical Areas of Northern China

Whole-plant corn silage is a predominant forage for livestock that is processed in Heilongjiang province (Daqing city and Longjiang county), Inner Mongolia Autonomous Region (Helin county and Tumet Left Banner) and Shanxi province (Taigu and Shanyin counties) of North China; it was sampled at 0, 5, 14, 45 and 90 days after ensiling. Bacterial community and fermentation quality were analysed. During fermentation, the pH was reduced to below 4.0, lactic acid increased to above 73 g/kg DM (p &lt; 0.05) and Lactobacillus dominated the bacterial community and had a reducing abundance after 14 days. In the final silages, butyric acid was not detected, and the contents of acetic acid and ammonia nitrogen were below 35 g/kg DM and 100 g/kg total nitrogen, respectively. Compared with silages from Heilongjiang and Inner Mongolia, silages from Shanxi contained less Lactobacillus and more Leuconostoc (p &lt; 0.05), and had a separating bacterial community from 14 to 90 days. Lactobacillus was negatively correlated with pH in all the silages (p &lt; 0.05), and positively correlated with lactic and acetic acid in silages from Heilongjiang and Inner Mongolia (p &lt; 0.05). The results show that the final silages had satisfactory fermentation quality. During the ensilage process, silages from Heilongjiang and Inner Mongolia had similar bacterial-succession patterns; the activity of Lactobacillus formed and maintained good fermentation quality in whole-plant corn silage.

Abundance and diversity of epiphytic microbiota on forage crops and their fermentation characteristic during the ensiling of sterile sudan grass.

This study aimed to evaluate the effects of exogenous epiphytic microbiota inoculation on the fermentation quality and microbial community of sudan grass silage. Gamma irradiated sudan grass was ensiled with distilled water (STR), epiphytic microbiota of sudan grass (SUDm), forage sorghum (FSm), napier grass (NAPm) and whole crop corn (WCCm). The FSm inoculated silage have significantly lower lactic acid (LA) concentration and higher pH during early ensiling, while LA concentration gradually and significantly increased with the progression of ensiling and have lower pH in relation to other treatments for terminal silage. Inoculation of NAPm resulted in lower LA and higher acetic acid (AA) concentrations, higher pH, ammonia-N and dry matter losses for terminal silage, followed by SUDm silage. Inoculations of WCCm significantly increased LA production and pH decline during early ensiling and have higher LA and pH then NAPm and SUDm silages during final ensiling. The early fermentation of SUDm silage was dominated by genus of Pediococcus. The genera of Lactobacillus were predominant in WCCm and NAPm silages during 3days of ensiling, while Weissella dominated initial microbial community of FS silage. The terminal silage of NAPm was dominated by Enterobacter and Rosenbergiella, while Enterobacter and Lactobacillus dominated terminal SUDm silage. The final silage of FSm was dominated by Lactobacillus, Weissella and Pediococcus, while Lactobacillus and Acetobacter dominated terminal WCCm silages. The results demonstrated that among the four forages the epiphytic microbiota from forage sorghum positively influenced the microbial community and fermentability of sudan grass silage.

Effects of various epiphytic microbiota inoculation on the fermentation quality and microbial community dynamics during the ensiling of sterile Napier grass.

To investigate epiphytic microbiota transformation of forages, their adaptation and contributions to fermentation quality of silage. Gamma-irradiated chopped Napier grass were ensiled with distilled water (STR), extracted epiphytic microbiota of Napier grass (NAP), sudan grass (SUD), whole crop corn (WCC) and forage sorghum (FS). Inoculating Napier grass with WCC significantly increased lactic acid (LA) concentrations during the initial ensiling period followed by a decline after 30days. Relative to other silages (except STR) inoculation with NAP resulted in lower LA and greater pH, ammonia-N and dry matter (DM) losses. Silage inoculated with FS and SUD maintained lower pH as well as higher (P<0·05) LA concentrations after 60days of storage. During day 3 of ensilage, WCC, NAP and SUD inoculated silage were dominated by bacterial genera of Lactobacillus, while Lactococcus dominated the FS silage. Final silages were dominated by Lactobacillus in all treatment silages, however Enterobacter (16·3%) in NAP and Acetobacter (25·7%) in WCC silage were also prominent during the final ensiling. The inoculation of epiphytic microbiota of forage sorghum and sudan grass positively influenced the microbial community and fermentability of sterile Napier grass silage. This is the first time to investigate the effects of various epiphytic microbiota as silage inoculants which can be used as alternative source of environmental friendly and economically feasible silage additives.

Microbial diversity and fermentation profile of red clover silage inoculated with reconstituted indigenous and exogenous epiphytic microbiota

The study investigated the effects of transplantation and reconstitution of indigenous and exogenous epiphytic microbiota on the fermentation quality and microbial community of red clover silage. Sterile red clover was inoculated with distilled water (RC0), extracted epiphytic microbiota of red clover (RC), maize (MZ), and sorghum (SG). RC inoculation rapidly decreased pH at the onset of ensiling. The LA concentration and ratio of LA/AA were higher in RC silage during entire ensiling while MZ silage during late phase of ensiling. Pediococcus was dominant in RC early silage, while Lactobacillus was abundant in MZ final silage. The SG terminal silage had higher pH (>4.50) and dominated by Sphingomonas, Enterobacter, and Novosphingobium. RC and MZ microbiota were beneficial in enhancing fermentation quality and microbial community in red clover silage. Transplantation and reconstitution of epiphytic microbiota can be a successful method to assess the effective and eco-friendly additive for the targeted crop.

Effects of lactic acid bacteria inoculation in pre-harvesting period on fermentation and feed quality properties of alfalfa silage.

ObjectiveTo develop the fermentation quality and chemical composition of alfalfa (Medicago sativa Lam.) silage, plants were inoculated with different lactic acid bacteria (LAB) strains at field 24 hours before harvest.MethodsThe treatment groups were as follow: silage without additive as a control and inoculated with each strains of Lactobacillus brevis (LS-55-2-2), Leuconostoc citerum (L. citerum; L-70-6-1), Lactobacillus bifermentans (L. bifermentans; LS-65-2-1), Lactobacillus plantarum (L. plantarum; LS-3-3) and L. plantarum (LS-72-2). All the silages were stored at 25°C. Parameters such as pH, microorganism and volatile fatty acid contents, crude protein, neutral detergent fiber, acid detergent fiber, net gas, metabolizable energy, organic matter digestibility, dry matter intake and relative feed value were measured to determine fermentation quality, chemical compositions and relative feed value of alfalfa silages.ResultsSignificant differences were found among the control and treated groups in terms of pH and microorganism contents at all opening times and crude protein, net gas, metabolizable energy and organic matter digestibility of final silage. The pH values ranged from 4.70 to 5.52 for all treatments and control silage had the highest value of overall treatments at T75d silages. Volatile fatty acid of silages was not influenced significantly by inoculations. However, lactic acid content of L. bifermentans (LS-65-2-1) was higher than the other treatments. The highest metabolizable energy and organic matter digestibility were recorded from L. citerum (L-70-6-1) inoculation. In addition, no significant differences were found among treatments in terms of neutral detergent fiber, acid detergent fiber, dry matter intake and relative feed value.ConclusionAmong the treated LAB isolates, L. bifermentans came into prominence especially in terms of organic acid composition and quality characters of silages.

Nutritive value and fermentation characteristics of round-baled alfalfa–orchardgrass forages ensiled at various moisture concentrations with or without baler cutting engagement

ABSTRACT Objective The objectives of this research were to compare the silage fermentation characteristics and nutritive value of cut and uncut alfalfa (Medicago sativa L.)–orchardgrass (Dactylis glomerata L.) baled silages packaged at moisture concentrations ranging between 40 and 70%. Materials and Methods Thirty-one 1.2 × 1.2 m round bales made from an alfalfa–orchardgrass stand (56.5% alfalfa; 42.7% orchardgrass) were baled either cut or uncut over 4 bale groupings (67.5, 61.5, 51.1, and 45.8% moisture). The cutting mechanism within the baler was configured with 15 knives spaced at ~7.5 cm. The experimental design was a randomized complete block with 4 replications (field blocks); we evaluated a 4 moisture groupings × 2 particle lengths (cut or uncut) factorial arrangement of treatments. Results and Discussion Cutter engagement increased initial wet bale weights (668 vs. 641 kg; P = 0.003) but had no effect on nutritive value (P ≥ 0.104). Final silage pH was best related to initial bale moisture with a linear regression model for both cut (Y = −0.031x + 7.50; R2 = 0.847) and uncut (Y = −0.033x + 7.74; R2 = 0.869) silages. The cumulative effects of improved fermentation for cut forages represented pH declines of about 0.10 to 0.16 pH units over initial bale moistures ranging from 40 to 70%. Implications and Applications Bale moisture had a greater effect on fermentation than the use of bale-cutting systems. The modest fermentation improvements observed in cut bales suggest only limited potential for improved silage fermentation on that basis.

Chemical composition and nutritive value of corn silage harvested in the northeastern United States after Tropical Storm Irene

In the fall of 2011, Hurricane (Tropical Storm) Irene caused significant damage to the forage corn crop in the northeastern United States. Compromised crops were subjected to various degrees of flooding, lodging, and contamination with sediment. The objective of this study was to determine if compromised plants harvested for silage fermented normally and if the nutritive value of these silages was adversely affected. The chemical and nutrient composition of compromised silages was compared with that from silages made from unaffected plants from the same region. The concentration of NEL and in vitro digestibility of NDF were lower in plants compromised by the hurricane. In addition, the ash content of compromised silages was higher than that of unaffected silages. Specifically, concentrations of Al, Co, Fe, and Mn were higher in compromised silages. Overall, silage fermentation appeared to be normal; the final silage pH, and concentrations of fermentation acids, alcohols, and esters were similar between compromised and unaffected silages. Numbers of yeasts (but not molds) tended to be higher in compromised silage than in unaffected silage. Pathogenic microorganisms were not detected in any silage. The incidences and concentrations of mycotoxins were similar between compromised and normal silage. Several farms that fed compromised silage reported subsequent health issues with their animals.

The effect of relocation of whole-crop wheat and corn silages on their quality

Whole-crop wheat and corn silages in 1.5-L anaerobic jars were exposed to air for 0 up to 48h during their anaerobic storage period to simulate relocation of silages. Ensiling treatments included control (no additives) and either Koffosil T (Koffolk Inc., Petah Tikva, Israel) comprising a mixture of organic acids or Lactobacillus plantarum MTD1 (Ecosyl Products Ltd., Stokesley, UK). In the first set of experiments, the duration of exposure to air had little effect on ensiling parameters or on the aerobic stability of the final silages. In the second set of experiments, both the inoculant and duration of exposure to air had an effect on various fermentation parameters and on the aerobic stability of the final silages. We concluded that if the silages are of good quality, the duration of the relocation process has little effect on silage quality or its aerobic stability. However, if the silage contains any factor that may affect its aerobic stability, it is more sensitive to the time it takes to re-ensile the forage.

Effect of ensiling moist field bean (Vicia faba), pea (Pisum sativum) and lupine (Lupinus spp.) grains on the contents of alkaloids, oligosaccharides and tannins.

Ensiling legume grain may be an inexpensive and ecologically interesting method to produce a high-protein feed of local origin. The typically patchy maturation recommends harvesting and ensiling the seeds in moist condition. Developing a method for preserving legume grains harvested before maturation by lactic acid fermentation would have several advantages. Under laboratory conditions, crushed legume seeds of beans, peas and lupines with high moisture content of 35% were ensiled with different additives (molasses and lactic acid bacteria). To characterize the final silages, contents of proximate nutrients and antinutritional factors (alkaloids, oligosaccharides, tannins) were analysed. The addition of lactic acid bacteria ensured a fast and pronounced lactic acid production and decreased contents of undesired fermentation products like ethanol. An additional use of molasses for ensilage did not provide a remarkable additional benefit. Excluding sugar and starch, the contents of proximate nutrients were not remarkably altered after ensiling. As an overall effect, lactic acid fermentation reduced tannins and oligosaccharides. It can be supposed that the oligosaccharides after breakdown of the complex molecules acted as a source of fermentable carbohydrates. A relevant reduction of alkaloids did not occur. The lactic acid fermentation of legume grains can be recommended as an appropriate method for conservation. With respect to the economic advantages and compared with methods of chemical preservation, the lactic acid fermentation of legume grains under anaerobic conditions is an environmentally compliant procedure and therefore also an option for organic farming.

Avaliação da qualidade nutricional da silagem de cana-de-açúcar com aditivos microbianos e enriquecida com resíduo da colheita de soja

Objetivou-se avaliar as características fermentativas e a qualidade nutricional da silagem de cana-de-açúcar tratada com aditivos microbianos e enriquecida com 10% de resíduo da colheita de soja, com base no peso verde da cana. O experimento foi conduzido em delineamento inteiramente ao acaso, com três repetições, utilizando-se a variedade RB855536, colhida em soca aos 16 meses. Embora a adição do resíduo da colheita de soja tenha promovido aumento do pH final da silagem, os tratamentos com resíduo diminuíram em 33% as perdas de matéria seca das silagens e em 60% o teor de N-amoniacal em relação ao nitrogênio total. A adição dos inoculantes reduziu o pH da silagem quando em associação ao resíduo de soja, não exercendo efeito significativo sobre os outros parâmetros estudados. Em todos os tratamentos, as silagens apresentaram maiores concentrações dos componentes da fibra e redução nos teores de MS em relação ao material original, antes da ensilagem. Nos tratamentos com resíduo, os valores de digestibilidade in vitro da matéria seca (DIVMS) foram superiores aos obtidos nos demais tratamentos. Quando comparado o material utilizado para ensilagem, a redução na digestibilidade foi superior para os tratamentos sem o resíduo (24,3 vs 9,3%). A associação do resíduo da colheita de soja à cana-de-açúcar para ensilagem proporcionou melhor qualidade nutritiva, com menores perdas de MS e carboidratos solúveis, principalmente na forma de gases, e, conseqüentemente, menor acúmulo dos componentes da parede celular, além de redução na DIVMS da forragem. Não se recomenda a utilização dos inoculantes L. plantarum e L. buchneri na ensilagem da cana-de-açúcar, pois nenhuma melhoria foi observada na composição química ou no perfil de fermentação das silagens.

Fate of Escherichia coli during Ensiling of Wheat and Corn

A recombinant Escherichia coli strain carrying a plasmid with an antibiotic resistance marker and expressing the green fluorescent protein was inoculated at a concentration of 3.8 x 10(8) CFU/g into direct-cut wheat (348 g of dry matter kg(-1)), wilted wheat (450 g of dry matter kg(-1)), and corn (375 g of dry matter kg(-1)). The forages were ensiled in mini-silos. The treatments included control (no E. coli added), application of tagged E. coli, and delayed sealing of the inoculated wheat. Three silos per treatment were sampled on predetermined dates, and the numbers of E. coli were determined on Chromocult TBX medium with or without kanamycin. Colonies presumptively identified as E. coli were also tested for fluorescence activity. Addition of E. coli at the time of ensiling resulted in a more rapid decrease in the pH but had almost no effect on the chemical composition of the final silages or their aerobic stability. E. coli disappeared from the silages when the pH decreased below 5.0. It persisted longer in silages of wilted wheat, in which the pH declined more slowly. Control silages of all crops also contained bacteria, presumptively identified as E. coli, that were resistant to the antibiotic, which suggests that some epiphytic strains are naturally resistant to antibiotics.

In vitro evaluation of fibrolytic enzymes as additives for maize ( Zea mays L.) silage : II. Effects on rate of acidification, fibre degradation during ensiling and rumen fermentation

A study was carried out to determine the influence of fibrolytic enzymes derived from mesophilic or thermophilic fungal sources, added at ensiling, on time-course fermentation characteristics and in vitro rumen degradation of maize silage. The mesophilic enzyme was a commercial product derived from Trichoderma reesei (L), whereas the thermophilic enzyme was a crude extract produced from Thermoascus aurantiacus (Ta) in this laboratory. The fungus was cultured using maize cobs as a carbon source. The resulting fermentation extract was deionised to remove sugars and characterised for its protein concentration, main and side enzymic activities, optimal pH, protein molecular mass and isoelectric point. In an additional study, both enzymes were added to maize forage (333.5 g DM/kg, 70.0, 469.8, 227.1 and 307.5 g/kg DM of CP, NDF, ADF and starch, respectively) at two levels each, normalized according to xylanase activity, and ensiled in 0.5 kg capacity laboratory minisilos. Duplicate silos were opened at 2, 4, 8, 15, and 60 days after ensiling, and analysed for chemical characteristics. Silages from 60 days were bulked and in vitro gas production (GP) and organic matter degradability (OMD) profiles evaluated using the Reading Pressure Technique (RPT), in a completely randomised design. The crude enzyme extract contained mainly xylanase and endoglucanase activities, with very low levels of exoglucanase, which probably limited hydrolysis of filter paper. The extract contained three major protein bands of between 29 and 55 kDa, with mainly acidic isoelectric points. Ensiling maize with enzymes lowered ( P<0.05) the final silage pH, with this effect being observed throughout the ensiling process. All enzyme treatments reduced ( P<0.05) ADF contents. Treatments including Ta produced more gas ( P<0.05) than the controls after 24 h incubation in vitro, whereas end point gas production at 96 h was not affected. Addition of Ta increased ( P<0.01) OMD after 12 h (410 and 416 g/kg versus 373 g/kg), whereas both L and Ta increased ( P<0.05) OMD after 24 h. Addition of enzymes from mesophilic or thermophilic sources to maize forage at ensiling increased the rate of acidification of the silages and improved in vitro degradation kinetics, suggesting an improvement in the nutritive quality.

Ensiling salt-preserved shrimp waste with grass straw and molasses

Two experiments were conducted to evaluate the nutritional and fermentation characteristics of ensiled salt-preserved shrimp waste. In Experiment 1, 7.5% salt-preserved shrimp waste was stored for 6 days then mixed with molasses and perennial ryegrass straw. Treatments included three levels of shrimp waste (83, 65 and 47%, as mixed) within which there were three levels of dry molasses (0, 9, or 17%, as mixed). Mixtures were stored in 15-l mini-silos for 40 days. The resulting nine shrimp silages, which ranged from 33 to 52% DM and 11 to 21% CP, never reached a pH of <4.5, which is necessary for a stable grass silage. The silages that incorporated a high amount of shrimp waste (83%) and molasses (9 or 17%) with low levels of straw had high levels of lactic acid production but only a slight drop in pH. The high buffering capacity from the calcium carbonate in the shrimp waste may have diminished the effectiveness of the acids to change the pH of the final silage. When a lower level of shrimp waste (47%) and molasses were ensiled with high levels of grass straw, the pH remained high because of low lactic acid production. The use of low quality forages or, either the amount or source of carbohydrate substrates, may have limited bacterial growth and acid production. Without a pH of <4.5, the stability and the possible presence of bacterial pathogens in our shrimp waste silages make this a questionable feed to offer ruminants. In Experiment 2, two fistulated steers were used to evaluate the ruminal undegradable protein of fresh shrimp waste and shrimp silage (47% shrimp waste, 17% molasses). The samples were deposited into nylon bags and placed in the rumen at nine time points ranging from 0 to 96 h. Prior to insertion of the samples, steers were stuffed via the fistula with crustacean waste for a 2-week adjustment period. The ruminal undegradable protein was 57% for the fresh shrimp waste and 32% for the shrimp silage.

The effect of temperature and Lactobacillus amylovorus and Lact. plantarum, applied at ensiling, on wheat silage

The effects of applying Lactobacillus plantarum and Lact. amylovorus at ensiling on wheat silage stored at 25 and41 °C was studied under laboratory conditions. The inoculants were applied at 106 cfu g−1.Silages with no additives served as controls. Three jars per treatment were sampled on days 2, 8 and 60 after ensiling, for chemical and microbiological analyses. After the ensiling period, the silages were subjected to an aerobic stability test. The control and Lact. plantarum inoculated wheat fermented faster at 25 than at 41 °C, whereas silages inoculated with Lact. amylovorus fermented faster at 41 °C. This was apparent from the rate of pH decrease and from the contents of residual sugars and lactic acid in the final silages. The numbers of lactobacilli in the control and Lact. plantarum silages at 41 °C after 2 and 8 days of ensiling were lower than in the corresponding silages at 25 °C. For the Lact. amylovorus silage the opposite held true. The control silages at both temperatures and the Lact. plantarum silage at 41 °C were the most stable silages under aerobic exposure.

A survey on the effect of management techniques and pasture composition and quality at harvesting on silage quality on dairy farms in western Victoria

Summary. Factors associated with silage quality were investigated on 140 dairy farms in western Victoria. The management factors measured were date of lock up, date cut, length of lock up, duration of wilting, raking and tedding during wilting period, rainfall during wilting period and the type of silage made. Pasture variables measured at harvesting included percentage composition (ryegrass, legume, other grasses and weeds), dry matter of pasture, metabolisable energy, crude protein, neutral detergent fibre and water-soluble carbohydrate of the pasture, and dry matter yield of the pasture. The average lock up time of pasture for silage was mid September, although the range was from late July to early November. The length of lock up varied from 16 to 91 days with a mean value of 49 days and pastures were on average harvested in early November. Ryegrass on average accounted for 61%, legumes and other grasses accounting for a further 15% each and weeds about 5%. The range in quality of pasture at harvesting was highlighted by the range in metabolisable energy (8.9–11.3 MJ/kg DM) and crude protein (10.2–20.4%) values. Wilting times varied from 0.5 to 15 days with the biggest range being observed in pastures used for baled silage. All factors were regressed against final silage metabolisable energy and crude protein. Factors which had the greatest effect on final silage metabolisable energy were date of cutting, length of lock up, type of silage, the interaction between type of silage and length of lock up, length of wilting and mechanical treatment during the wilting period. Final silage crude protein was most strongly associated with date of cutting, crude protein content of the pasture and mechanical treatment during the wilting period. Mechanical treatment during the wilting period had the greatest influence on silage quality. Other options to improve silage quality such as cutting earlier or reducing wilting periods may not be possible or economically viable.

The effect of cellulase and hemicellulase plus pectinase on the aerobic stability and fibre analysis of peas and wheat silages

The effect of applying increasing levels of cellulase and hemicellulase plus pectinase (Celluclast ® and Viscozyme ®, Novo, Denmark) to peas and wheat silages was studied under laboratory conditions. The enzymes were applied at 0.02, 0.1 and 0.2% each, corresponding to 0.3, 1.5 and 3.0 NCU (Novo cellulase units) of Celluclast, and 0.024, 0.12 and 0.24 FBG (fungal β-glucanase units) of Viscozyme per gram of fresh crop. All treatments were enriched with a lactic acid bacteria inoculum, applied at 10 4 colony-forming units per gram of forage. The following parameters of final silages (45 days) had a significant ( P < 0.05) linear regression on log (enzyme concentration + 1): pH, residual sugars, lactic acid, NDF (neutral detergent fibre) and ADF (acid detergent fibre). When enzyme levels increased from 0 to 0.2%, the NDF and ADF contents decreased from 355 and 317 to 303 and 255 g kg −1, respectively, in the pea silages, and they decreased from 568 and 357 to 522 and 340 g kg −2, respectively, in the wheat silages. Enzyme treatments resulted in enhanced aerobic deterioration in both pea and wheat silages. This was evident from higher yeast and mould counts, more intensive CO 2 production and visible mould growth during exposure to air for 5 days.