Aerobic Stability Research Articles

Fermentation quality, bacterial community, and aerobic stability of ensiling Leymus chinensis with lactic acid bacteria or/and water after long-term storage.

Leymus chinensis is a major forage resource for herbivores on typical steppe and meadow steppes in Northern China. This study aimed to reveal the fermentation quality, bacterial community, and aerobic stability of L. chinensis silage treated with lactic acid bacteria or/and water after long-term storage. Leymus chinensis was harvested at the heading stage and ensiled with lactic acid bacteria [LAB, 2.00 ml/kg fresh weight (FW) of LAB, L], water (100 ml/kg FW of distilled water, W), or a combination of both [2.00 ml/kg fresh weight (FW) of LAB and 100 ml/kg FW of distilled water, LW] in polyethylene laboratory-scale silos (diameter, 20 cm; height, 30 cm) at a density of 650 kg/m3. As a control silage (CK), untreated L. chinensis silage was also assessed. The samples were taken at 0 day of opening after 300 days of ensiling (CK_0d, L_0d, W_0d, and LW_0d) and at 10 days of opening (CK_10d, L_10d, W_10d, and LW_10d). The fermentation quality, microbial counts, bacterial community, and aerobic stability of the silage were assessed. The CK_0d contained higher pH and aerobic bacteria count, and lower LA and BC concentrations than L_0d, W_0d, and LW_0d (p < 0.05), and the LAB and yeasts were only detected in CK at 0 day of opening. Lactobacillus had the most abundance among bacterial genera in all silages at 0 day of opening. Just CK had 2°C above the ambient temperature during aerobic exposure (at 224 h). During aerobic exposure, the pH and microbial counts in CK increased (p < 0.05), and Lactobacillus in L and LW had decreasing abundance (p < 0.05). The CK_10d had higher pH and microbial counts, and lower lactic acid and buffering capacity than L_10d, W_10d, and LW_10d (p < 0.05). At 10 days of opening, the coliforms and yeasts were just detected in CK, and Lactobacillus also had the most abundance among bacterial genera in all silages at 10 days of opening. Overall, inoculating LAB and adding water improved the fermentation quality and the aerobic exposure of L. chinensis silage after long-term storage. The activities of coliforms and yeasts during aerobic exposure contributed to the aerobic deterioration of L. chinensis silage without any treating. Lactobacillus dominated the bacterial communities of all silage at 0 and 10 days of opening. During aerobic exposure, the abundance of Lactobacillus reduced in L. chinensis silage treated with LAB or water.

Applying the benzoate equivalent concept in rehydrated corn grain silage

The benzoate equivalent (BEq) concept is a potential tool to compare silage additives that differ in active ingredients and their respective concentrations. Thus, our objective was to define BEq coefficients for potassium sorbate and sodium propionate in comparison to sodium benzoate, and establish an application rate based on the BEq to extend the aerobic stability of rehydrated corn grain silage. Dry corn kernels were ground (hammer mill, 8-mm screen), rehydrated to 350 g/kg moisture, and treated as follows: no additive (control), potassium sorbate (PS) at 125, 250, 500 and 1000 g/t, sodium benzoate (SB) at 250, 500, 1000 and 2000 g/t, sodium propionate (SP) at 500, 1000, 2000 and 4000 g/t, and a mixture of SB, PS and SP (BPS) at 250 + 150 + 53 g/t, 375 + 225 + 79 g/t, 500 + 300 + 105 g/t and 625 + 375 + 132 g/t, respectively. Treated grain was stored for 60 d in laboratory silos. All additives, alone or mixed, decreased the yeast and mold counts, ethanol and ethyl ester concentrations, and DM loss during fermentation, whereas more water-soluble carbohydrates were preserved in the treated silages. The untreated (control) corn grain silage rapidly deteriorated upon air exposure (∼ 41 h of aerobic stability), and PS, SB, and SP, alone or mixed, linearly improved the aerobic stability with increasing application rate. PS (BEq = 1.99) was more effective than SB (BEq = 1), and SB was more effective than SP (BEq = 0.35) in enhancing the aerobic stability. An application rate of approximately 1400 g/t of BEq could extend the aerobic stability of rehydrated corn grain silage for 3 d over that of untreated silage. In conclusion, the BEq concept is a plausible tool to compare commercial silage additive preparations and define their application rates in corn grain silage.

Cold temperature drives the re-granulation of disintegrated partial nitritation granules in a continuous-flow reactor

To investigate the effect of temperature on the recovery of aerobic granule stability, two continuous-flow reactors inoculated with disintegrated partial nitritation granules were operated at different temperatures for organic-free wastewater treatment. Granules disintegration and partial nitritation deterioration further occurred in the reactor (R1) operating at 25–28 °C. However, successful sludge re-granulation with a decrease of sludge volume index (SVI5) from 73 mL/g to 35 mL/g was observed in the reactor (R2) operated with the decreasing temperature from 20 °C to 12 °C. The reduced temperatures decreased the activity and growth rate of nitrifiers (from 47.2 mg/g VSS/h to 21.3 mg/g VSS/h), and selected the extracellular polymeric substance (EPS) producing bacteria (e.g., Flavobacterium and Rhodobacteraceae sp.). Correspondingly, an enhanced secretion of tightly-bound EPS (200.3–224.6 mg/g VSS in R2 vs 166.8–152.5 mg/g VSS in R1), particularly proteins, and an increased expression of quorum sensing-related enzyme genes (2.98% in R2 vs 2.75% in R1) were obtained. All of this contributed to the cold temperature-driven sludge re-granulation. The recovery of granular structure promoted the stable maintenance of efficient partial nitritation at low temperatures. Overall, this study gives insights into the positive role of cold temperatures on the stability of partial nitritation granules.

Nutritive value, silage fermentation characteristics, and aerobic stability of grass-legume round-baled silages at differing moisture concentrations with and without manure fertilization and microbial inoculation.

For baled silages, production of clostridial fermentation products can be exacerbated by exceeding normal moisture targets (45% to 55%), and/or by the application of dairy slurry before harvest. Our objectives were to test a microbial inoculant as a mitigant of clostridial products in high-moisture, grass-legume (52% ± 13.8% cool-season grasses, 44.0% ± 14.0% legumes [predominately alfalfa]) baled silages in swards that were fertilized with dairy slurry. A secondary objective was to examine the effects of bale moisture and inoculation on the aerobic stability of these fermented silages following exposure to air. After the first-cutting was removed, three manure treatments were applied as a whole-plot factor: 1) control (no manure); 2) slurry applied immediately to stubble (63,250 L/ha); or 3) slurry applied after a 1-wk delay (57,484 L/ha). An interactive arrangement of bale moisture (64.1% or 48.4%) and inoculation (yes or no) served as a subplot term in the experiment. The inoculant contained both homolactic (Lactococcus lactis 0224) and heterolactic (Lactobacillus buchneri LB1819) bacteria. The experimental design was analyzed as a randomized complete block with four replications, and the study included 48 experimental units (1.2 × 1.2-m round bales). Total fermentation acids were affected (P ≤ 0.021) by slurry application strategies, but this was likely related to inconsistent bale moisture across slurry-application treatments. Concentrations of butyric acid were low, and there were no detectable contrasts comparing manure treatments (mean = 0.05%; P ≥ 0.645). Bale moisture affected all measures of fermentation, with bales made at 64.1% moisture exhibiting a more acidic final pH (4.39 vs. 4.63; P < 0.001), less residual water-soluble carbohydrates (2.1% vs. 5.1%; P < 0.001), as well as greater lactic acid (4.64% vs. 2.46%; P < 0.001), acetic acid (2.26% vs. 1.32%; P < 0.001), and total fermentation acids (7.37% vs. 3.97%; P < 0.001). Inoculation also reduced pH (4.47 vs. 4.56; P = 0.029), and increased acetic acid (1.97% vs. 1.61%; P < 0.001) and 1,2-propanediol (1.09% vs. 0.72%; P < 0.001) compared to controls. During a 34-d aerobic exposure period, maximum surface bale temperatures were not affected (P ≥ 0.186) by any aspect of treatment, likely due to the prevailing cool ambient temperatures; however, yeast counts were numerically lower in response to greater (P < 0.001) production of acetic acid that was stimulated by both high bale moisture and inoculation.

Microbial inoculant and cottonseed cake as additives for millet silage at different fermentation times

ABSTRACT The purpose of the present study was to evaluate the effect of the addition of microbial inoculant and cottonseed cake on the fermentation profile, microbial population, aerobic stability, organic acids, chemical composition and losses of millet silages. The experimental design was completely randomised, in a 4 × 2 factorial arrangement, with the following treatments: (1) Control (millet); (2) Millet + 10% cottonseed cake (on a natural matter basis); (3) Millet + Weissella cibaria – heterofermentative lactic acid bacteria; (4) Millet + cottonseed cake and Weissella cibaria (blend); and two opening times (30 and 90 days after ensiling) with four replications, totalling 32 experimental units. Silages containing cottonseed cake had greater (P = .008) dry matter recovery. There was effect (P < .001) of the opening time on the counts of lactic acid bacteria, mould and yeast, and under aerobic stability, which were higher in silages opened at 90 days. The addition of cottonseed cake resulted in an increase in the nutritional quality of the silage, compared to control silages and silages inoculated with Weissella cibaria. The addition of cottonseed cake in millet silage proved to be efficient in reducing silage losses, improving the fermentation profile and nutritional value.

Effects of Wafer Addition on Fermentation Properties, Aerobic Stability and Feed Value of Alfalfa Silages

Effects of Wafer Addition on Fermentation Properties, Aerobic Stability and Feed Value of Alfalfa Silages

Effects of a mixture of Lentilactobacillus hilgardii, Lentilactobacillus buchneri, Pediococcus pentosaceus and fibrolytic enzymes on silage fermentation, aerobic stability, and performance of growing beef cattle.

This study evaluated the effects of novel silage inoculants containing lactic acid bacteria (LAB) and fibrolytic enzymes on ensiling, aerobic stability (AS), and the performance of growing beef cattle. Whole-plant corn forage was either uninoculated (CON) or inoculated with a mixture of LAB containing (cfu g-1 fresh forage) 1.5 × 105 L. hilgardii (CNCM I-4785), 1.5 × 105 L. buchneri (NCIMB 40788) and 1.0 × 105 P. pentosaceus (NCIMB 12455) for a total of 4.0 × 105 cfu g-1 fresh forage LAB (IB), or a combination of IB plus fibrolytic enzymes (xylanase + β-glucanase) (IC). All treatments were ensiled in mini-silos, whereas CON and IC were also ensiled in silo bags for the growth performance study. Total bacteria (TB) counts were lower (P = 0.02) for IC than CON after 14 d of ensiling, whereas TB counts of IC and IB were greater (P ≤ 0.01) than CON after 60 d of ensiling in mini-silos. The LAB in IC and IB ensiled in mini-silos were greater than CON on d 60 (P ≤ 0.01) and 90 (P ≤ 0.001) of ensiling and after 3 d (P ≤ 0.01) of aerobic exposure (AE). Silage pH of IC ensiled in silo bags was lower than CON on d 3 (P < 0.01), 7 (P < 0.001), and 14 (P = 0.02) of AE. Yeast counts were lower for IC than CON in terminal silage (P < 0.001), and after 3 (P < 0.001) and 7 d (P < 0.01) of AE. Acetate (AC) concentrations were higher (P ≤ 0.02) for IC than CON throughout AE, whereas lactate (LA) concentrations of IC were greater than CON on d 3 (P < 0.001), 7 (P < 0.01), and 14 (P < 0.001) of AE. Greater AC concentration and lower yeast counts resulted in greater (P < 0.001) stability for IC ensiled in silo bags than CON after 14 d of AE. Growth performance of steers was similar (P > 0.05) as the nutrient composition of silage was similar across diets. Improved AS of IC could potentially have a greater impact on DMI, production efficiency, and growth performance in large-scale commercial feedlot operations where silage at the silo face may be exposed to air for longer periods of time.

Effects of adding agro-industrial by-products and bacterial inoculant at ensiling on nutritional quality and bacterial colonization of Tifton 85 [&lt;i&gt;Cynodon dactylon&lt;/i&gt; (L.) Pers.] silages

The objective of this study was to evaluate effects of adding agro-industrial by-products (soybean hulls and cornprocessing residue) and bacterial inoculant to Tifton 85 forage at ensiling on nutritional quality and bacterial colonization of resulting silages. The design was completely randomized in a 3 × 2 factorial scheme, with 6 treatments and 4 replicates. Treatments were: Tifton 85 forage; Tifton 85 + soybean hulls; Tifton 85 + corn-processing residue; Tifton 85 + bacterial inoculant; Tifton 85 + soybean hulls + inoculant; and Tifton 85 + corn-processing residue + inoculant. Inclusion of by-products increased dry matter and organic matter percentages of silages, while addition of soybean hulls improved crude protein concentration in silage. Total digestible nutrients in silages containing by-products were higher than in straight Tifton 85 silage. In addition, addition of by-products increased in vitro dry matter and organic matter digestibilities of resulting silages. Most treatments showed aerobic stability up to 144 hours after exposure to air, except for Tifton 85 + corn-processing residue without inoculant, which became unstable by 120 hours of exposure. Addition of by-products at ensiling of Tifton 85 forage appears beneficial but there seems little benefit in adding bacterial inoculant. More studies on a larger scale are needed to confirm these preliminary results, while feeding studies would determine any improvement in animal performance when fed silage containing by-products.

Limnological Investigations of Sewage Stabilization Ponds at Sewage Treatment Plant in Bikaner (NW Rajasthan)

Abstarct: Geographically Bikaner has four natural slopes, one towards the vallabh garden area, where the three anaerobic and two aerobic stabilization ponds of sewage treatment plant are situated in the North –West part of the Rajasthan. The Thar desert lies which is characterized by typical arid conditions like scarcity of water, low rainfall, intense radiations, violent winds, high temperature fluctuations and dust storms. This paper is based on the chemical limnological study of three anaerobic and two aerobic stabilization ponds of sewage treatment plant. The study was carried out for a period of 15 months from March 2010 to May 2011. The chemical parameters measured include pH, EC (electrical conductance), TDS (total dissolve solids), and Free CO2. The parameters of three anaerobic stabilization ponds of water was ranged pH (6.7 to 8.2), EC (1.5 mmhos/cm to 2.0 mmhos/cm), TDS (960 mg/l to 1280 mg/ l), Free CO2 (172 mg/l to 294 mg/l) and two aerobic stabilization ponds of water was ranged pH (7.3 to 8.4), EC (1.3 mmhos/cm to 1.8 mmhos/cm), TDS (832 mg/l to 1152 mg/ l) and Free CO2 (152 mg/l to 270 mg/l) were recorded.

Effects of Sour Yogurt as an Alternative Additive in Second Crop Corn Silage

In this study, we evaluated the influence of sour yogurt as a natural microbial inoculant in second-crop corn silages. For this purpose, two trials with different dilution rates were conducted. In Trial I, the groups 10 g sour yogurt + 5 g distilled water (SY10-2), 20 g sour yogurt + 10 g distilled water (SY20-2), 30 g sour yogurt + 15 g distilled water (SY30-2), 40 g sour yogurt + 20 g distilled water (SY40-2), 50 g sour yogurt + 25 g distilled water (SY50-2) and no additives were added to the control (CON) group. The groups in Trial II, 10 g sour yogurt + 10 g distilled water (SY10-1), 20 g sour yogurt + 20 g distilled water (SY20-1), 30 g sour yogurt + 30 g distilled water (SY30-1), 40 g sour yogurt + 40 g distilled water (SY40-1), 50 g sour yogurt + 50 g distilled water (SY50-1) and 10 g of distilled water were added to the control (WCON) group. For the silages opened on the 90th day of ensiling, the highest lactic acid content was determined in the SY20-2 and SY20-1 groups (p &lt; 0.05). The lowest amount of ammonia nitrogen was in the SY30-2 group (p &lt; 0.05). In the aerobic period, the SY10-2 and SY20-2 groups remained more stable than the others. As a result, the SY20-2, SY30-2, SY20-1, and SY30-1 groups improved the fermentation quality of corn silages, but the effect on aerobic stability was not significant and was similarly found with the homofermentative bacterial inoculants.

Fermentation dynamics, nutritional quality, and heating capacity of mixed silages of elephant grass (Pennisetum purpureum Schum) and Leucaena (Leucaena leucocephala)

Leucaena has been used to make mixed silages to obtain nutritional enrichment of the silages. Thus, the inclusion of Leucaena as an additive in mixed elephant grass silages can reduce fermentation losses, and increase the nutritional value and aerobic stability of the mixed silage without changing the fermentation profile. This study evaluated the fermentation profile, nutritional composition, and aerobic stability of elephant grass silages combined with different levels of Leucaena. A total of five inclusion levels of Leucaena (0, 20, 40, 60, and 80% on a dry matter basis) were added to elephant grass silages. A completely randomized design was adopted, with 5 treatments and 3 repetitions, totaling 15 experimental silos that were opened after 30 days of sealing. Fermentation profile, chemical composition, and aerobic stability were analyzed. A descriptive analysis of temperature and pH peaks during aerobic stability was performed. The increase in the inclusion of Leucaena in the composition of silages reduced gas and effluent losses, neutral and acid detergent fiber, cellulose, lignin, total and fiber carbohydrates, and total digestible nutrients, and resulted in increased dry matter, ether extract, and crude protein. A quadratic effect of treatments was found for the temperature to reach the maximum pH (P=0.009). Aerobic stability remained constant after 40% Leucaena inclusion in the composition of elephant grass silages. The inclusion of Leucaena up to 80% in the composition of elephant grass silages reduces fermentation losses, promotes a nutritional increase, and increases the aerobic stability of the silages.

Fermentation profile, aerobic stability, chemical and mineral composition of silages of mango combined with cocoa pod husk meal

The objective was to evaluate the fermentation profile, aerobic stability, chemical composition, and mineral content of silages of mango combined with cocoa pod husk meal. A completely randomized design was adopted, including four levels (65, 70, 75, and 80%) and five repetitions, totaling 20 experimental silos that were opened after 90 days of sealing. Increasing mango levels in the silages increased the dry matter recovery, total carbohydrates, and fraction B2 of carbohydrates, and reduced gas losses, dry matter, and mineral matter. The quadratic effect was found for pH, buffering capacity, potassium, boron, iron, and nitrogen fractions A and B1 + B2. Using unconventional products such as mango combined with cocoa pod husk meal for silage making can reduce the cost of food supplementation for ruminants, and the environmental contamination.

Yüksek Nemli Dane Mısıra Bakteriyel İnokulant İlavesinin Silolama Süresi ve Aerobik Stabilitesi Üzerine Etkileri

Bu çalışma, yüksek nemli dane mısıra homofermantatif + heterofermantatif özelliklere sahip iki farklı inokulantın ilave edilmesinin, farklı açım dönemlerinde (15 ve 30 gün) fermantasyon ve aerobik stabilite üzerine etkilerini belirlemek amacıyla düzenlenmiştir. Araştırma materyalini yaklaşık %64.84 kuru madde (KM) içeriğine sahip kırılmış yüksek nemli dane mısır oluşturmuştur. Laktik asit bakteri inokulantı olarak Pioneer 11CFT (Lactobacillus plantarum ATCC 55944, Lactobacillus buchneri ATCC PTA-6138) ve Lalsil combo (Lactobacillus plantarum CNCM MA 18/5U, Lactocbacillus buchneri NCIMB 40788) kullanılmıştır. İnokulant firma önerisi doğrultusunda silajlara ilave edilmiştir. Katkı maddesi ilavesinden sonra silaj örnekleri her muamele grubunda 5’er tekerrür olmak üzere plastik torbalara vakumlanarak doldurulmuştur. Paketler laboratuvar koşullarında 20 ± 2 °C sıcaklıkta depolanmışlardır. Fermantasyonun 15. ve 30. günü açılan silaj örneklerinde kimyasal ve mikrobiyolojik analizler yapılmıştır. Açım dönemi sonrası silajlara 5 günlük aerobik stabilite testi uygulanmıştır. Araştırma sonucunda, silolama süresine bağlı olarak silajların pH değeri, amonyağa bağlı nitrojen (NH3-N), suda çözünebilir karbonhidrat (SÇK), lactobacilli (LAB) ve maya içerikleri artarken, KM içerikleri ise düşmüştür (P&lt; 0.001). Katkı maddesi ilaveli silajların, NH3-N, SÇK, laktik asit (LA), LAB ve maya içerikleri kontrol grubu silajlarına oranla daha yüksek, pH değerleri ise daha düşük tespit edilmiştir (P

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.

The effect of cultivar and stage of growth on the fermentation, aerobic stability and nutritive value of ensiled Quinoa

Quinoa can be an important source of silage as an alternative forage crop. However, there is limited information on the ensiling of quinoa. This study aimed to investigate the silage fermentation quality, nutritive value and aerobic stability of quinoa cultivars harvested at different plant growing stages. The experiment was carried out in experimental area of the Hatay Mustafa Kemal University, Faculty of Agriculture in 2019 and 2020 growing seasons. The experiment was laid out in a split plot in randomized block design with three replications, three main plots were harvesting times (flowering, milky and dough stages) and five sub-plots were cultivars (Mint Vanilla, Cherry Vanilla, French Vanilla, Red Head and Titicaca). Traits such as pH, ammonia nitrogen, lactic acid bacteria, lactic acid, acetic acid, butyric acid, propionic acid, ethanol, dry matter, neutral detergent fiber, acid detergent fiber, acid detergent lignin, crude protein, ash, ether extract, water soluble carbohydrate and relative feed value were investigated to determine silage fermentation quality and nutritive value. In addition, all silages were evaluated in terms of aerobic stability. Among the evaluated quinoa cultivars in terms of fermentation quality, cv. Titicaca and cv. French Vanilla provided superior results compared to other cultivars. It was also determined that it would be more appropriate to harvest these superior quinoa cultivars during the dough stage for quality silage. Among the silages, the cv. Titicaca had the best aerobic stability. As a result of this study, it was concluded that cv. French Vanilla and cv. Titicaca should be harvested during the dough stage to obtain better silage quality. According to the results of this study, it was deduced that the quinoa plant could be an alternative ensiling crop.

Exploring the effect of wilting on fermentation profiles and microbial community structure during ensiling and air exposure of king grass silage.

In order to better understand the effect of wilting treatment on silage, we study analyzed the fermentation quality of unwilted (CK) and wilted (WT) king grass silage, and the dynamic changes of microorganisms in silage and aerobic exposure. After 30 days of silage, WT silage significantly reduced the pH of the silage (p < 0.05) and increased the contents of lactic acid and acetic acid (p < 0.05), but did not reduce the content of Ammonia-N (p > 0.05). Wilting treatment increased bacterial and fungal diversity during silage but decreased fungal diversity during aerobic exposure. The relative abundance of Lactococcus and Enterococcus in wilting silage increased. In the aerobic exposure stage, the relative abundance of Klebsiella decreased, but the relative abundance of Enterobacter increased in wilting treatment silage. In addition, the relative abundance of Acinetobacter and Ignatzschineria increased after 5 days of aerobic exposure. In contrast with unwilted silage, wilting treatment silage after aerobic exposure had no Candida, but the relative abundance of Wickerhamomyces increased. The results showed that wilting treatment could raise the silage quality of king grass. However, WT silage did not inhibit the reproduction of harmful microorganisms during aerobic exposure and did not significantly improve the aerobic stability of silage.

Efficacy of adding chemical and microbial additives to silage on beef cattle performance: Systematic review and meta‐analysis

AbstractThe effects of different additives on farm‐scale silage quality and beef cattle performance are inconsistent. This study aimed to carry out a systematic review and meta‐analysis to evaluate the efficacy of chemical and microbial additives to silage on beef cattle performance. Systematic searches were performed using databases and scientific journals, and 42 articles were selected. Data for all variables were grouped into subgroups according to the additive type. For dry matter intake and average daily gain, the data were also grouped by forage type due to greater comparison numbers. The treatment mean differences and 95% confidence intervals (p &lt; 0.05) were analysed using a random‐effects model. The use of homo‐ and heterofermentative microbial inoculant mixtures and chemical additives (Ch) increased the average daily gain of beef cattle fed maize/sorghum silage. Homofermentative microbial inoculant (Ho), Ch, and a mixture of microbial inoculant and chemical additives also increased the average daily gain of beef cattle fed temperate grasses. Only Ch increased dry matter intake. Ch increased feed efficiency, and Ch and Ho increased carcass weight. The evaluated additives improved the silage fermentation process mainly via pH and ammonia nitrogen reduction. Overall, this meta‐analysis demonstrated that silage additives improved the ensiling process and beef cattle performance, with better results with Ch use. Due to the aerobic stability and microbiological profile analyses being carried out more in laboratory‐scale silos, more studies are needed to determine these silage parameters after opening the silo at the farm scale.

Effects of Lactic Acid Bacteria Additives on the Quality, Volatile Chemicals and Microbial Community of Leymus chinensis Silage During Aerobic Exposure.

Silage exposed to air is prone to deterioration and production of unpleasant volatile chemicals that can seriously affect livestock intake and health. The aim of this study was to investigate the effects of Lactobacillus plantarum (LP), Lactobacillus buchneri (LB), and a combination of LP and LB (PB) on the quality, microbial community and volatile chemicals of Leymus chinensis silage at 0, 4, and 8 days after aerobic exposure. During aerobic exposure, LP had higher WSC and LA contents but had the least aerobic stability, with more harmful microorganisms such as Penicillium and Monascus and produced more volatile chemicals such as Isospathulenol and 2-Furancarbinol. LB slowed down the rise in pH, produced more acetic acid and effectively improved aerobic stability, while the effect of these two additives combined was intermediate between that of each additive alone. Correlation analysis showed that Actinomyces, Sphingomonas, Penicillium, and Monascus were associated with aerobic deterioration, and Weissella, Pediococcus, Botryosphaeria, and Monascus were associated with volatile chemicals. In conclusion, LB preserved the quality of L. chinensis silage during aerobic exposure, while LP accelerated aerobic deterioration.

The Use of Whey Powder Additions for Grass Silage: Effects on Nutrient Content, Fermentation Properties and Aerobic Stability

The aim of this study was to determine the nutrient content, fermentation properties, and aerobic stability of grass ensiled with the addition of different doses of whey powder. Freshly cut grasses (Festuca arundinacea, Festuca rubra, Poa pratensis, and Lolium perenne) were ensiled with the addition of whey powder at a rate of 0, 2, 4, and 6% in the laboratory in 1.5-liter plastic jars with 4 replications. At the end of the 60-day ensiling period, the nutrient content, fermentation properties, and aerobic stability values of silages were investigated. The pH measurements revealed that the silages were of high quality. Although dry matter (DM), crude protein (CP), and ether extract (EE) values increased depending on the increase in whey powder rate in the silages, crude ash (CA), ADF, and NDF values decreased. The lowest pH and the highest Fleig Score (FS) were obtained in silage with a 6% whey powder addition. Except in the control group, no mold formation was detected in silage groups after the seven-day aerobic stability test. As a result, different mixing ratios of grass and whey powder did not cause negative results in silages and increased the quality. According to Fleig scores and aerobic stability results, the best quality silages were obtained from silages with 4 and 6% whey powder additions. It was concluded that the ensiling of grass with whey powder was effective in improving the nutritional and fermentation quality of silages and provided a partial solution to environmental pollution.

Effects of cellulose-based bio-plastics on the aerobic biological stabilization treatment of mixed municipal solid waste: A lab-scale assessment.

The aim of this work is to assess how the presence of cellulose-based bio-plastics influence the biological stabilization of mixed Municipal Solid Waste (MSW). For the scope, two cellulose acetate bio-plastics have been mixed with a synthetic mixed waste to create samples with and without bio-plastics. A self-induced biostabilization has been carried out for 7 and 14 days where temperature and off-gas have been monitored continuously. Results about temperature evolution, O2 consumption, CO2 production and respiratory quotient did not show a substantial difference regarding both the duration of the process and the presence of cellulose-based bio-plastics on the mixture. On the average, the temperature peak and the maximum daily O2 consumption and CO2 production were 52.2°C, 35.81g O2/kg DM *d and 48.95g CO2/kg DM *d respectively. Disintegration of bio-plastics samples after 7 and 14 days were comparable (on the average 23.13%). The self-induced biostabilization gave its main contribution after 4 days and resulted almost finished at the end of the day 7 of the process. Results showed that cellulose-based bio-plastics did not give a negative effect on mixed MSW biological stabilization and suggest a possible management, aiming at energy recovery of the outputs.