Aerobic Stability Of Silage Research Articles

PSXI-5 Transforming retailer’s food waste into silage for sustainable animal nutrition

Abstract Food waste (FW) represents a major environmental and socio-economic problem. In Canada, about 11.2 million metric tons of avoidable food waste is produced yearly. An alternative to reduce this impact would be preserving a greater proportion of this, for livestock feed. Therefore, the objective of this study was to use discarded fruits, vegetables, and bakery products from retailers (FW), ensile them, and assess their nutritional value and contribution to a sustainable livestock feed supply. For this, two treatments for reducing the moisture content of FW were evaluated: Sun-dried (SD), and Passive-dried (PD), were compared with Control (C), using laboratory mini-silos over 60 d of ensiling. Although dry matter (DM) increased by 1-5% for PD and SD, respectively, up to 41.9% of bread products were required to produce a targeted silage DM of 38%. Silage aerobic stability was assessed during 20 d exposure to air. Chemical analyses (pH, volatile fatty acids, lactic acid, ammonia) were assessed in pre-fermentation (d 0), and post-fermentation (d 60). Nutritional quality was evaluated according to AOAC standard methods. Statistical analyses employed mixed models for nutritional and fermentation data, with drying treatments (C, PD, SD) as fixed effects. All mature silages were greater in crude protein (15.2 to 15.7%), crude fat (6.0 to 6.3%), sodium (0.48 to 0.52 %), sugars (WSC; 0.95 to 1.53 %), and less in neutral detergent fiber (6.2 to 7.6%) as compared with traditional silages used as livestock feed. Fermentation parameters showed that lactic acid content was greater than acetic acid, and pH decreased from a maximum of 5.26 at d 0 to a minimum of 3.85 at d 60. Mycophenolic acid was the only mycotoxin above the limit of detection in d 0 silage, with all mycotoxins below reference concentrations at d 60. Plate counts of molds and yeasts declined (P < 0.001) by 5 to 7 log colony-forming units (CFU) over 60 d of fermentation and were not detected in mature silage. Silage showed aerobic stability after 20 d of aerobic exposure (pH 3.86 ± 0.027). In conclusion, ensiling FW could be a viable way of converting low-value waste products into good-quality feed. However, approaches other than SD and PD are required for increasing silage DM as insufficient bread products may be available for this purpose in all batches of FW. Further study of palatability along with digestibility testing will be needed for a scaling-up process.

155 Modulating silage fermentation with microbial inoculants

Abstract Silage is a vital feed ingredient for beef and dairy cattle diets in many areas worldwide. Even though ensiling is a well-established method of forage preservation, producers face a myriad of challenges to produce, harvest, and store forages optimally. Challenging circumstances like these create difficulties for proper silage fermentation, increase dry matter (DM) losses and silage contamination with mycotoxins, and reduce the nutritive value of ensiled forages. Losses of DM and nutrients occur during production, fermentation, and feeding of silage. Although some losses are unavoidable, poor management may increase DM losses up to 60% which may eventually lead to decreased feed efficiency, as each percentage-unit lost as DM is a percentage-unit of feed that cannot be converted into animal products. Loss of DM during forage production and preservation is estimated to cost beyond a billion dollars worldwide. Even in well-managed silages, yeasts and molds that survive anaerobic fermentation may grow rapidly and reduce aerobic stability after silo opening, and mold count in silage is positively related to DM loss. The use of silage microbial inoculants is a key strategy to modulate silage fermentation and preserve forage successfully. This presentation will discuss microbial inoculant strategies to optimize silage fermentation and minimize silage losses. Homofermentative bacterial inoculants, which contain bacteria that almost exclusively produce lactic acid, have been shown to effectively reduce silage pH and improve DM recovery. The use of homofermentative microbial inoculants have been shown to attenuate DM loss during ensiling and to increase dry matter intake and hence lactation performance by dairy cows. Heterofermentative bacterial inoculants, which contain bacteria capable of producing both lactic and acetic acids, reduce mold and yeast counts and improve silage aerobic stability.

Evaluation of chitosan and microbial inoculants on aerobic stability and fermentative profile pearl millet, corn and sorghum silages

ABSTRACT The objective of this study was to evaluate the effect of microbial inoculants, chitosan, and blend (microbial inoculants and chitosan) on chemical composition, in vitro degradability, fermentative profile, losses, aerobic stability, and microorganism counts of corn, pearl millet and sorghum silages. A randomised block design was used in a factorial arrangement of 3 × 4. Three crops (pearl millet, corn and sorghum) and four additives: Control (without additive), 2 g of microbial inoculants (for ton of forage), 10 g/kg chitosan per kg of ensiled material, and blend (chitosan [5 g/kg] plus microbial inoculants [2 g/ton forage]), with five replicates per treatment. Chitosan increases the CP levels of silages and improves the in vitro degradability of DM in sorghum silage. The microbial inoculants reduced the pH in pearl millet, corn and sorghum silages (P < 0.001). The additives affected (P < 0.05) the aerobic stability of silages throughout the evaluation period. However, when evaluating the chitosan, the average temperature of the pearl millet and corn silages remained stable for a longer period. Chitosan improved the nutritional quality of sorghum silage. Chitosan-treated silages pearl millet and corn silages show great efficiency in aerobic stability due to antifungal activity. The microbial inoculants show reduced gas losses compared to chitosan.

Effects of kinds of additives on fermentation quality, nutrient content, aerobic stability, and microbial community of the mixed silage of king grass and rice straw.

To investigate the effects of kinds of additives on silage quality, the mixture of king grass and rice straw was ensiled with addition of sucrose, citric acid and malic acid at the levels of 0, 1 and 2%, being blank control (CK), citric acid groups (CA1, CA2), malic acid groups (MA1, MA2), citric acid + malic acid groups (CM1, CM2), sucrose groups (SU1, SU2), mainly focusing on fermentation quality, nutrient content, aerobic stability and microbial community of the silages. The results showed that the addition of sucrose decreased (p < 0.05) pH and increased the content of water soluble carbohydrate (p < 0.05). The sucrose groups and mixed acid groups also had a lower (p < 0.01) neutral detergent fiber content. The addition of citric acid and the mixed acid increased (p < 0.01) the aerobic stability of the silage, reduced the abundance of Acinetobacter, and the addition of citric acid also increased the abundance of Lactiplantibacillus. It is inferred that citric acid and malic acid could influence fermentation quality by inhibiting harmful bacteria and improve aerobic stability, while sucrose influenced fermentation quality by by promoting the generation of lactic acid. It is suggested that the application of citric acid, malic acid and sucrose would achieve an improvement effect on fermentation quality of the mixed silage.

Improvements in fermentation and nutritive quality of elephant grass [Cenchrus purpureus (Schumach.) Morrone] silages: a review.

Elephant grass [Pennisetum purpureum Schumach. syn. Cenchrus purpureus (Schumach.) Morrone], also known as Napier grass and King grass, includes varieties Taiwán, Gigante, Merkerón, Maralfalfa, and others. The grass achieves high biomass production in tropical-subtropical, temperate, and arid areas. The high-water concentration of elephant grass suggests that ensiling could offer an alternative way to preserve the nutritional quality of the grass during storage, however, some considerations should be addressed because of the particularities of the grass. Ensiling elephant grass may produce adequate fermentation but could suffer effluent losses and subsequent losses of nutrients due to leaching. To improve fermentation and nutrient characteristics of elephant grass silages, several studies were conducted with the inclusion of additives. Lactic acid bacteria inocula have reduced pH and increased crude protein content of elephant grass silage, but aerobic stability of silages could be affected by the bacterial inoculation. There is limited information, however, on the potential of different silage inoculants to reduce growth of spoilage microorganisms during the aerobic phase of silage prepared with elephant grass. Exogenous fibrolytic enzymes also may improve elephant grass silage quality by enhancing microbial fiber-degradation with subsequent increase in lactic acid and its associated pH reduction. Another study approach to improve fermentation and nutritional quality of elephant grass silages involved the addition of different feeds at ensiling, including conventional feeds such corn, wheat, rice bran, and molasses or alternative feeds such as different dehydrated by-products obtained from the food industries of juice and jelly. In the manuscript, the presented scientific information shows the great potential of the different manipulations to improve the quality of elephant grass silages and with possible enhance of the economic profit and sustainability of livestock farming in the tropical areas.

Lactic acid bacteria and manganese‐based additives for improved lucerne, perennial grass, and perennial grass‐white clover preservation as silage

AbstractLactic acid bacteria (LAB) are commonly used as silage inoculants. Manganese sulphate (MnSO4) has been proposed to protect certain LAB during oxygen exposure and improve silage aerobic stability (ASTA). The aim of the present study was to assess the efficacy of inoculants in preservation of different forages. A short‐term screening trial investigated the effect of 24 additive treatments, compared to a negative control, on ensiling perennial grass in mini‐silos (2.75 L) for 7 d. The additive treatments comprised different ratios of Lactiplantibacillus plantarum [IMI 507026, IMI 507027, and IMI 507028] and Pediococcus pentacaceus [IMI 507024 and IMI 507025], with or without MnSO4. Target parameters, such as low levels of fresh matter loss, pH, acetic acid, ammonia‐nitrogen fraction (NH3–N/Total N), and high levels of lactic acid and ASTA, were considered for treatment selection. Eight treatments were selected based on a principal component analysis and hierarchical clustering of the target parameters. These selected treatments subsequently underwent a 100 d long‐term trial using lucerne, perennial grass, and perennial grass‐white clover forages. All silages treated with the eight additives exhibited an improved homolactic fermentation and a lower (p &lt; .001) pH, acetic acid, and ethanol content than the control. Although DM losses and ASTA markedly improved in the treatments containing MnSO4 in the short‐term trial, these effects were not observed in the long‐term trial. These outcomes suggest that the selected additives can improve silage fermentation quality across a broad range of forages, but further studies are required to assess the impact of MnSO4 on ASTA.

Bacillus velezensis promotes the proliferation of lactic acid bacteria and influences the fermentation quality of whole-plant corn silage.

This study aimed to investigate the promoting effect of a Bacillus velezensis (BV) strain on lactic acid bacteria (LAB) and determine its influence on the fermentation quality and aerobic stability of silage. Flat colony counting method was used to evaluate the effect of BV on the growth of LAB. Freshly harvested whole-plant corn was inoculated separately with BV and L. plantarum (LP), along with an uninoculated control group (CK), and assessed at 1, 3, 5, 7, 15, and 30 days of ensiling. The results indicated that BV exhibited a proliferative effect on Weissella confusa, Lactobacillus plantarum L-2, and Pediococcus pentosaceus. And exhibited a more rapid pH reduction in BV-inoculated silage compared with that in CK and LP-inoculated silage during the initial stage of ensiling. Throughout ensiling, the BV and LP experimental groups showed enhanced silage fermentation quality over CK. Additionally, relative to LP-inoculated silage, BV-inoculated silage displayed reduced pH and propionic acid. BV also prolonged aerobic stability under aerobic conditions. The microbial community in BV-inoculated silage showed greater stability than that in LP-inoculated silage. Additionally, Firmicutes and Lactobacillus exhibited more rapid elevation initially in BV versus LP-inoculated silage, but reached comparable levels between the two inoculation groups in the later stage. In summary, BV enhanced the efficacy and aerobic stability of whole-plant corn silage fermentation by stimulating LAB proliferation.

Perfil fermentativo, valor nutricional e estabilidade aeróbia de silagens mistas de capim-elefante e cunhã

Abstract The aim was to evaluate the effect of butterfly pea inclusion on the fermentation dynamics, nutritional quality and aerobic stability of mixed elephant grass silages. Butterfly pea levels (0, 20, 40, 60 and 80% on a natural matter basis) were added to elephant grass silages. A completely randomized design was adopted, with 5 treatments and 3 replications, totaling 15 experimental silos, which were opened after 30 days of fermentation. The inclusion of butterfly pea in elephant grass silages resulted in a quadratic effect for permeability, density, maximum pH, final pH, time to reach maximum temperature and aerobic stability (P&lt;0.05). Butterfly pea inclusion levels increased dry matter recovery, pH, dry matter, organic matter, ether extract, crude protein and total digestible nutrients (P&lt;0.001) and reduced gas and effluent losses, mineral matter, neutral detergent fiber, acid detergent fiber, hemicellulose, cellulose, lignin and total carbohydrates (P&lt;0.001). Inclusions of 40, 60 and 80% of butterfly pea provided temperature increases at 10, 20, 30 and 40 hours. The inclusion of butterfly pea with levels of up to 80% reduces fermentation losses, allows for a nutritional increase and increase in aerobic stability of silages.

Придание аэробной стабильности кукурузному силосу при химическом консервировании

Aerobic stability of corn silage, as well as other types of silage, can be achieved by chemical preservation. Currently, mainly organic acids and their salts are used as chemical preservatives. The highest preservative effect is provided by undissociated forms of acids. Dissociation occurs most intensely in a reaction environment close to neutral and is significantly inhibited in an acidic environment. To give silage aerobic stability, the chemical preservative must have fungicidal and static properties, since the main initiators of aerobic decomposition are yeast. Of the organic acids, propionic acid has such properties to the highest extent, and acetic acid to a somewhat lesser extent. Other representatives of organic acids with fungicidal properties not inferior to propionic acid are benzoic, sorbic, acrylic and others. Salts of these acids also have similar properties. The use of mixtures of acids and salts significantly enhances their preservative effect, provided that their components interact synergistically. In addition to these mixtures, the fungicidal effect of a mixture of monoglycerides: monopropionate and monobutyrate has recently been established. Unlike biological products, the fungicidal effect of chemical preservatives manifests itself from the first days of use.

Effects of inoculation of corn silage with Saccharomyces cerevisiae on silage fermentation characteristics, nutrient digestibility, mycoflora and aflatoxin production

In the present study, fresh whole corn plants along with half milk kernels line were treated with live and hydrolysed yeast with different concentrations before ensiling and kept in airtight bags and then into mini silos in order to achieve anaerobic conditions for proper fermentation. The buckets were opened after different time intervals to characterise the material, quick acidification, dry matter recovery, and aerobic stability of silage respectively. Moreover, mycoflora and aflatoxin contamination were also analysed. The overall result reported that the silage quality was improved by the application of live and hydrolysed yeast. The best result was reported by the application of live yeast (T2: 10 g/kg) which significantly improved the fermentative, proximate, and digestibility parameters and reduced the mycoflora and aflatoxin contamination. Our results present promising new options for the use of natural compounds that may help to improve silage quality and reduce aflatoxin contamination.

Assessment of Maize Silage Quality under Different Pre-Ensiling Conditions

Maize silage suffers from several factors that affect the final quality and, to some extent, pre-ensiled conditions that can be potentially tuned during harvesting. After assessing new indices for silage quality under lab-scale conditions, several trials have been conducted to find associations between fresh maize characteristics and silage features. Among the first, we included field input levels, FAO class, maturity stage, use of bacterial inoculants, sealing delay and chemical traits, whereas, among the latter, we assessed density and porosity, pH, fermentative profile, dry matter loss and aerobic stability. The trials were conducted using vacuum bags or mini silo buckets. More than 1500 maize samples harvested in Northeast Italy were analysed during the 2016–2022 period. Moreover, to evaluate silage aerobic stability, the fermentative profile and temperature were measured 14 days after the opening of the silo. The association between silage quality and aerobic stability was assessed, and a prognostic risk score was used to calculate the probability of aerobic instability. The dataset could provide baseline information to promote the continuous improvement of maize silage management from different botanical and crop fields, thus improving agronomic and animal farm resource allocation from a precision agriculture perspective.

Effect of application rate of sodium nitrite and hexamine on the fermentation and the chemical composition of guinea grass silage harvested at different stages of maturity

Grass ensilability varies with maturity stage, mainly due to changing concentrations of dry matter and soluble carbohydrates with progressing forage maturity. Consequently, the required dose of silage additive to prevent the development of undesirable microorganisms may change with maturity stage. The objective of this study was to verify whether the application rate of an additive containing sodium nitrite and hexamine interacts with guinea grass maturity to alter silage fermentation and chemical composition. Four fields of guinea grass (0.5–0.7 ha each field) were mowed and divided into two plots per field. After 5 wk, one plot of each field was mowed again to establish differences in stage of maturity. Ten weeks after the first mowing, the grass plots with 5- and 10-wk regrowth were manually harvested and used for the trial. The grass from each plot (approx. 30 kg) was chopped and divided into 3 piles, totaling to 24 piles, as result of four fields, two maturities, and three additive treatments: control (without additive), low dose of sodium nitrite (0.5 g/kg) + hexamine (0.325 g/kg) (NHL), and high dose of sodium nitrite (1 g/kg) + hexamine (0.65 g/kg) (NHH). After 90 d of storage, the silos were opened and silages sampled to determine dry matter (DM) loss, microbial counts, fermentation end-products, aerobic stability, chemical composition, and in vitro DM digestibility. Guinea grass harvested at 10-wk regrowth had a lower content of crude protein (P < 0.001) and a greater content of cell wall components (P < 0.001), resulting in a more lignified (P < 0.001) and less digestible (P < 0.001) forage than that harvested at 5 wk. There were interactions between plant maturity and additive dose for several silage traits (P < 0.05), likely due to the slightly greater fermentability coefficient (+5.1 points) for the more mature grass (P < 0.001). Within each maturity stage, silage pH and fermentation end-products associated with clostridia metabolism (i.e., n-butyric acid, propionic acid, i-butyric acid, i-valeric acid, n-valeric acid, ammonia, and 2,3-butanediol) linearly decreased (P < 0.001) with additive application rate, but the magnitude of improvement was slightly greater for 5-wk than 10-wk regrowth. Application of additive linearly decreased silage DM loss at both 5-wk (95.2, 46.7, and 20.6 g/kg DM, P < 0.001) and 10-wk (66.5, 31.7, and 13.6 g/kg DM, P < 0.001) regrowth stages, but only silages treated with NHH had n-butyric acid concentration < 3 g/kg DM. The proportion of rumen undegradable protein (P < 0.001), soluble carbohydrates concentration (P < 0.001), and in vitro DM digestibility (P < 0.001) were linearly increased with additive dose within each maturity stage. As treated silages were better conserved, silage aerobic stability was linearly reduced (P < 0.001) with additive dose, although all silages were aerobically stable for ≥ 4.7 d. In conclusion, the additive based on sodium nitrite and hexamine, applied at a regular dose, was able to largely restrict Clostridium development and DM losses during fermentation of guinea grass silage at both maturity stages. However, harvesting more mature grass markedly impaired its chemical composition and digestibility, rendering it no feasible strategy to reduce the additive application rate by half.

Storage time effects on whole-plant sorghum silage fermentation profile, aerobic stability and mycotoxin concentration

ABSTRACT This study aimed to evaluate the storage time effects on whole-plant sorghum silage nutrients fermentation profile, fermentation losses, mycotoxin concentrations and aerobic stability. Sixteen experimental silos (cylindrical bag with 32 cm i.d. and six kg of silage) were used in a completely randomised design to evaluate the following storage times: 45, 90, 180 and 360 days. Storage time linearly increased silage Ammonia-N, propionic and butyric acid concentrations. In addition, treatments had a quadratic effect on silage pH and concentrations of lactic and acetic acids. Storage time did not affect fermentation losses, dry matter recovery and zearalenone concentration. However, storage time linearly decreased silage dry matter concentration and linearly increased deoxynivalenol silage content. Aflatoxin and fumonisin were not identified in silage samples. Storage time linearly increased silage pH regardless of evaluation period, and temperature, 24 h after aerobic exposure. Thus, the storage time of whole-plant sorghum silage affects the fermentation profile, has no effect on fermentation losses, increases deoxynivalenol content and reduces silage aerobic stability.

Produção integrada de silagem de Urochloabrizantha e silagem de milho ou sorgo: avaliação agronômica, perdas de fermentação e estabilidade aeróbia da silagem

ABSTRACT: The present study evaluated germination, production, and morphological composition of Urochloabrizantha intercropped with corn and sorghum; and silage fermentation losses and aerobic stability of intercrop silage using microbial inoculant. Twenty experimental parcels (5.0 × 3.6 m) were used in a blocked randomized design to evaluate four treatments obtained from a 2 × 2 factorial arrangements: I) crop material (corn vs. sorghum) and II) Brachiaria (U. brizantha) establishment (present vs. absent). Corn- and sorghum-brachiaria integrated systems showed similar brachiaria germination, forage yield, and morphological composition. There was no crop and brachiaria interaction effect on the variables related to corn and sorghum plants and the total productivity. Brachiaria decreased the stem diameter and increased the population of maize and sorghum plants. However, it did not affect systems productivity. Microbial inoculation did not affect corn silage effluent losses and reduced sorghum silage effluent losses. In corn silage, brachiaria did not affect gas losses, while in sorghum silage, brachiaria increased the gas losses. Total losses were higher in sorghum silage than in corn silage, which resulted in a lower DM recovery. The treatments did not affect the pH of the silage after aerobic exposure. However, brachiaria increased silage temperature evaluated at 32 and 40 hours after aerobic exposure. Thus, corn or sorghum consortium has similar brachiaria morphological composition and productivity. Moreover, in intercropped silage, brachiaria increases effluent losses and reduces silage aerobic stability.

Effect of Ustilago maydis on the Nutritive Value and Aerobic Deterioration of Maize Silage

The common smut of corn, caused by Ustilago maydis, reduces the yield and quality of maize forage. When heavy infestations of corn smut occur, grain yields can be so severely decreased that the most viable economic alternative may be to harvest and ensile the crop. Only a couple of studies have attempted to investigate the influence of aerobic exposure on the nutritive value and aerobic stability of silage, which is prepared from smut-infected maize. In this study, individual whole corn plants were harvested by hand. The plants were distributed into three treatments: 0% infected, 50% infected, and 100% infected. The fresh forage was ensiled in triplicate for a 90-day period. Aerobic exposure lasted for 28 days. Samples were taken on the day of opening and on the 3rd, 7th, 14th, and 28th days. Near infrared spectroscopy (NIRS) calibration equations were used for the prediction of qualitative indicators. Silage prepared from 100% smut-infected maize had comparatively poor quality with dry matter loss, increasing pH and the low amount of starch. It was also distinguished with significant temperature increases from days 15 to 18 of aerobic exposure. Silage prepared from 50% smut-infected maize did not show significant quality changes over the period of the experiment, although it had inferior quality compared to the silage prepared from smut-free maize. While silage prepared from smut-infected maize had an overall worse quality than silage prepared from non-infected maize, it should not have an adverse effect on livestock health or production.

Efectos del suero ácido sobre la calidad química fermentativa y la estabilidad aeróbica del ensilado de grano de maíz rehidratado

The objective was to evaluate the fermentative, chemical characteristics and aerobic stability of corn grain silages rehydrated with whey fluid (WF) or whey powder (WP) and water, with or without the addition of inoculant (I). The corn grain was ground and hydrated adding water without chlorine and/or whey to reach 35 % humidity and stored in silos of 4.36 kg. After 45 d of fermentation, samples of the silages were submitted to chemical-fermentative analyses in opening of silos and 240 h of exposure to air. The aerobic stability of the silages was evaluating during 240 h has considered to the loss when the temperature of the ensiled mass exceeded the ambient temperature by 2 °C. A reduction in the acid detergent fiber (ADF) and lignin content of the silages was observed with the use of WF and WP. The levels of ammoniacal nitrogen (NH3-N) were the lowest for WF and WP (0.7 and 0.9 g/kg TN) and pH was 4.31 for WF after 240 h of aerobic exposure. The use of inoculants provided higher levels of Ash, ether extract (EE), and low buffering capacity (BC), in addition to reductions in ADF levels. The inoculated silages showed higher levels of NH3-N and pH after 240 h. The silage of corn grains rehydrated with WF provided ideal pH values, low NH3-N content, reduced levels of ADF and lignin, and improved aerobic stability. In addition to being a sustainable alternative, the use of fluid whey to rehydrate corn grains adds nutritional value and improves silage fermentation.

Effects of Sodium Benzoate Application, Silage Relocation, and Storage Time on the Preservation Quality of Sugarcane Silage

The present study explored the effects of sodium benzoate (SB), relocation, and storage time on the quality of sugarcane silage. The experiments followed a completely randomized design with a 2 × 4 × 2 factorial arrangement and four replicates. The treatments were as follows: (i) with (SB+) or without (SB−) SB (2 g∙kg−1 on a fresh matter basis); (ii) with (R) or without (R0) relocation for 12, 48, and 72 h (R12, R48, and R72, respectively); and (iii) storage for 10 or 60 days after relocation. SB− silage showed a lower (p &lt; 0.05) dry matter loss (DML = 155 g·kg−1) without relocation (R0). SB+ silage showed the highest (p &lt; 0.05) DML (257 g·kg−1) with R72. SB use reduced (p &lt; 0.05) the yeast count in silage that was stored for 10 days (SB+: 4.63 CFU·g−1; SB−: 5.58 CFU·g−1). The yeast count was higher (p &lt; 0.05) in silage that was stored for 10 days after relocation, regardless of the relocation time. SB use increased the aerobic stability of silage after 10 days of storage. Thus, SB application is effective for the inhibition of yeast in relocated sugarcane silage. We recommend the use of SB when silage is relocated for 12 h and stored for 60 days after relocation.

Re-ensiling and microbial inoculant use effects on the quality of maize silages exposed to air

Re-ensiling has increased worldwide due to the increase in marketing of silage between farms. However, litlle is known about the aerobic deterioration and microbial inoculants effect in this process. The aim of this study was to determine the re-ensiling and microbial inoculant use effects on the maize silage quality. Experimental treatments included maize silage exposed to air for zero or 18 h, with or without microbial inoculant use containing a mixture of Lactobacillus plantarum and Propionibacterium acidipropionici. The forage was ensiled in 20 plastic buckets (20 liters capacity) with five repetitions per treatment. The silos were opened after 116 days and the chemical composition, in vitro dry matter digestibility (IVDMD), fermentative parameters, microorganism counts, total dry matter (DM) losses and aerobic stability of silage were evaluated. Re-ensiling reduced the non-fibrous carbohydrates content by 14.8%, whereas it increased the neutral detergent fiber content by 6%. The IVDMD was reduced by 6.1% in re-ensiled silages. In addition, re-ensiling increased the losses due to gases, effluents, and total DM. Lower lactic acid content and higher acetic acid content in re-ensiled maize silages were also observed. However, IVDMD increased by 4.6% in inoculated silages. Re-ensiling reduced the nutritive value and IVDMD of maize silages and should be avoided in production systems. The microbial inoculant use was not effective in improving the re-ensiled silage quality, which does not justify its use in these conditions. Farms should avoid purchasing maize silage due to reduction in nutritional value in the re-ensiling process. However, in some cases where farms need to purchase silage for feeding planning, the time between silo opening and re-ensiling should be as short as possible to reduce nutrient loss. Furthermore, in this situation the inoculant use does not improve silage conservation, which makes its use unnecessary.

Efficacy of formic acid, enzymes, and microbial additives in silage on the performance of sheep: Systematic review and meta-analysis

This study aimed to carry out a systematic review and meta-analysis to evaluate the efficacy of chemical, enzymatic, and microbial additives on the silage quality and performance of sheep. After article selection using the Cochrane Library, Embase, Web of Science, LILACS and MEDLINE-PubMed databases and a manual search of scientific journals and the references of articles selected in the systematic review, 4257 articles published through May 2021 were identified. Fifty-four randomized control trials eligible for review were selected. Data were grouped into subgroups by the additive type (Mho = homofermentative microbial inoculant; Mhe = heterofermentative microbial inoculant; MMi = microbial inoculant mixture; Fa = formic acid; En = enzymes). The meta-analysis was performed using the “meta” package of R software. The data were analyzed using the random effects model and the raw mean difference with a 95% confidence interval (p < 0.05). Fa use reduced (p < 0.05) the silage crude protein digestibility (CPD) (−20.7 g/kg DM), and the ammonia nitrogen (NH3–N) (−53.6 g/kg total N), and acetic acid (−5.06 g/kg DM) content and pH (−0.325) and increased the animal nitrogen retention (1.30 g/day), and the dry matter (DM) (14.1 g/kg NM), crude protein (CP) (20.4 g/kg DM) and water-soluble carbohydrate (WSC) (11.5 g/kg DM) content. En use reduced (p < 0.05) the silage neutral detergent fiber digestibility (NDFD) (−33.1 g/kg DM), CP (−10.8 g/kg DM), neutral detergent fiber (NDF) (−49.1 g/kg DM), NH3–N (−25.5 g/kg total N) and acetic acid (−4.43 g/kg DM) content. Mho use increased (p < 0.05) the dry matter intake (DMI) (95 g/day), dry matter digestibility (DMD) (28.8 g/kg DM), CPD (26.6 g/kg DM), WSC (2.55 g/kg DM), nitrogen intake (2.23 g/day), retained nitrogen (2.19 g/day) and lactic acid (10.4 g/kg DM) content and reduced the mold count (−1.01 log10 CFU/g), NH3–N (−13.4 g/kg total N), acetic acid (−3.31 g/kg DM) content and aerobic stability (−33.8 h) of the silage. Mhe use increased (p < 0.05) the DMI (78.6 g/day), carcass yield (0.906%), DM (9.96 g/kg NM), aerobic stability (23 h) and acetic acid (19.9 g/kg DM) content and reduced the NDF (−20 g/kg DM) and ADF (−16.2 g/kg DM), yeast (−0.852 log10 CFU/g) and mold (−0.469 log10 CFU/g) counts. MMi use increased (p < 0.05) the average daily gain (17 g/day), DM (13.4 g/kg NM) and yeast (0.930 log10 CFU/g) count and reduced the silage pH (−0.037). All additive types improved the silage quality, but only MMi improved weight gain in sheep. Mhe increased silage aerobic stability and can be used for this purpose on commercial farms.

Effects of LAB Inoculants on the Fermentation Quality, Chemical Composition, and Bacterial Community of Oat Silage on the Qinghai-Tibetan Plateau.

Lactic acid bacteria (LAB) have been proposed for the control of undesirable fermentation and, subsequently, aerobic deterioration due to their ability to produce antimicrobial metabolites in silage mass. To investigate the effect of specific LAB on the silage fermentation characteristics and bacterial community composition of oat in cold regions, silages were treated without (control) or with three LAB strains (LB, Lentilactobacillus buchneri; nLP, low temperature tolerant Lactiplantibacillus plantarum; pLP, phenyllactic acid-producing Lactiplantibacillus plantarum), and then stored at ambient temperature (−2.63 ± 5.47–14.29 ± 5.48 °C) for 30, 60, and 90 days. Compared with control, inoculation of LAB decreased the final pH value, butyric acid content, ammonia-N of total N and dry matter loss of silage. Treatments with nLP and pLP increased (p < 0.05) lactic acid content, whereas LB increased (p < 0.05) acetic acid content of silage. Lactiplantibacillus and Leuconostoc dominated in the silages with relative abundance of 68.29–96.63%. A prolonged storage period enhanced the growth of Leuconostoc in pLP-treated silage. In addition, pLP increased (p < 0.05) the aerobic stability of silage as compared with nLP. In conclusion, inoculation of LAB improved silage fermentation and/or delayed aerobic deterioration by shifting bacterial community composition during ensiling. Phenyllactic acid-producing Lactiplantibacillus plantarum as an inoculant exhibited potential for high quality silage production.