Fermentation Losses Research Articles

Chitosan and microbial inoculants in whole-plant soybean silage

AbstractWhole-plant soybean silage (WPSS) is a potential high-protein roughage source for ruminant diets. However, WPSS can be difficult to ensile and fermentation is a challenge. This study was conducted to evaluate the effect of chitosan and microbial inoculants on fermentation profile, fermentation losses, chemical composition, and in vitro degradation of WPSS. Forty experimental silos (PVC tubing with 28 cm i.d. and 25 cm height) were produced. Soybean plants from 10 plots were ensiled in a completely randomized block design to evaluate the following treatments: (1) control (CON): WPSS without additives; (2) chitosan (CHI): WPSS additive with 6 g/kg DM of chitosan; (3) LBB: WPSS treated with 5.0 × 107 colony-forming units (CFU) of Lactobacillus buchneri (NCIM 40788) per kg of fresh matter and (4) LPP: WPSS treated with 1.6 × 108 CFU of Lactobacillus plantarum and 1.6 × 108 CFU of Pediococcus acidilactici per kg of fresh matter. Silos were opened 120 days after ensiling. Microbial inoculants reduced silage pH, whereas LPP-treated silos showed the lowest concentration of NH3-N, ethanol, butyric, acetic, branched-chain, and propionic organic acids. LBB-treatment decreased lactic acid bacteria (LAB) count relative to other treatments, and LPP-treatment showed the lowest fermentation losses, improving dry matter (DM) recovery. Relative to other treatments, LPP increased silage DM, organic matter, and decreased acid detergent insoluble crude protein (CP), improving DM and neutral detergent fibre in vitro degradation. Treatments showed no effect on silage aerobic stability. Thus, LPP-treatment improves fermentation profile, reduces fermentation losses, and increases the nutritional value of WPSS.

Effect of particle size on storage time of hydrated corn grain

Dry ground corn kernels are widely used as sources of energy readily available for microbial synthesis in the rumen. The objective of the present study was to measure the effect of particle size on the storage length of rehydrated and ensiled corn grain. Commercial corn was milled in 2-, 4-, 6-, 8-, and 10-mm sieves, rehydrated until reaching 65% DM, and ensiled for 14, 28, and 56 days, in a completely randomized design with a 5 x 3 factorial arrangement, with six replications per treatment. PVC mini-silos were used, with dimensions of 25 cm height x 10 cm of diameter. The variables DM, MM, CP, NDF, ADF, pH, molds and yeasts count, fermentative losses, in vitro degradability and aerobic stability were subjected to analysis of variance. The Tukey test was used to compare means. LAB counts was subjected to Wilcoxon's non-parametric test, considering significance at p < 0.05. Rehydrated corn silages with smaller particles (2 and 4 mm) showed higher LAB and mold counts, higher levels of CP and EE and higher density at opening silos than that of coarser particles. However, they showed lower percentages of DM, and were susceptible to microbial attack and faster temperature increases than were coarse particles during the chosen storage times. Silage subjected to 56 days of fermentation showed lower contents of NDF, ADF and CP, lower gas losses and lower pH values in aerobiosis, and increased levels of soluble protein (A + B1 fractions), losses by effluents, number of hours to reach maximum temperature, and time to break aerobic stability. Coarse-grind silages subjected to 56 days of storage showed better chemical composition, lower LAB and mold counts, and less susceptibility to microbial degradation when exposed to air.

Pupunha heart of palm residue silage as an option of roughage for ruminants

It was aimed in this study to evaluate the ensiled pejibaye residue in the feeding of ruminants as roughage. For the in vitro digestibility assay, a randomized block design was used, with four treatments (pejibaye residue without additives; pejibaye residue + banana residue; pejibaye residue + rice residue and pejibaye residue + citrus pulp), with four replications. The variables studied were: chemical composition, specific mass, pH, average particle size, fermentation temperature and fermentative losses. Apparent digestibility was performed with sheep in a completely randomized design, to evaluate the same treatments mentioned above, using five replications. Heart-of-palm pejibaye residue silages showed average particle size, pH and density values within the range appropriate for their manufacture. Among the additives used in this study, silage with 15 g/100g of rice provided improvements in several nutritional parameters, such as DM, NDF, ADF, CF and NDF/NFC. High moisture content impairs the ensiling process, but it was solved with high dry matter content ingredients addition to promote the material stability.

Avaliação de perdas fermentativas e recuperação de matéria seca de diferentes silagens de ração total

The objective of this research was to evaluate the rates of fermentative losses and the recovery of dry matter from different silages of total feed mixture. The total feed mixtures consisted of diets based on forage palm, elephant grass, gliricidia and other ingredients such as sugar cane bagasse, corn bran, soybean meal and urea. 25 experimental silos were made, distributed in a completely randomized design, with five treatments and five replications. The treatments consisted of different mixtures of total feed. The diets were balanced to obtain isoproteic diets. The silos remained sealed for 90 days. After opening, the rates of losses by gases and effluents and the rate of recovery of dry matter from silages were evaluated. Analysis of variance was performed with the results obtained. The averages were compared using the Tukey Test, at 5% probability. The total feed silages composed of forage palm with sugarcane bagasse showed significantly higher values (P <0.05). Gas losses in forage palm silages, alone and in conjunction with elephant grass, as well as elephant grass silages, showed values close to 1% of DM losses. Elephant grass silages had lower effluent loss values (1.9803 kg / ton MV) than those found in forage palm silages and forage palm silages with sugarcane bagasse (2.7259 kg / ton MV and 2.4386 kg / ton MV, respectively). The dry matter recovery rates found in this experiment ranged from 87 to 98%. Forage palm silages, forage palm silages with elephant grass and elephant grass silages showed higher dry matter recovery rates (97.49%; 95.03% and 98.19%, respectively). The silage of forage palm with sugarcane bagasse is not indicated, due to the higher rate of losses.

Fermentation losses of cactus silages with elephant grass

This study proposes to evaluate fermentation losses and dry matter recovery rate in cactus silages with elephant grass. The experiment was laid out in a completely randomized design with eight replicates. Treatments consisted of cactus silages with increasing levels of elephant grass (10, 20, 30 and 40 % on a fresh-weight basis). The material was ensiled in experimental PVC tubes and was evaluated after 200 days of fermentation. The inclusion of elephant grass in the silage did not influence its pH (4.55), effluent losses (77.78 kg/t of fresh matter) or dry matter recovery rate (69.03 %), but induced a linear increase in dry matter content (from 8.33 to 14.80 %) and a decrease in gas losses (from 30.33 to 17.20 %). The addition of up to 40 % elephant grass improves the fermentation profile of cactus silage.

Fermentative profile, losses and chemical composition of silage soybean genotypes amended with sugarcane levels

The experiment aimed to evaluate the fermentative and nutritional profile of the silage of four soybean plant genotypes (BRS 333 RR, Pampeanas: C50, C60, and C70) ensiled with levels of sugarcane (0, 25, 50, 75, and 100%). The experiments were conducted in a completely randomized design, in factorial scheme 4 × 5 (four soybean genotypes and five levels of sugarcane inclusion) with four replicates. Silages with 100% soybean plant presented the highest levels of butyric acid (P < 0.001) and ammoniacal nitrogen (P < 0.047); however, the intermediate addition of sugarcane contributed to lactic fermentation (P < 0.001). Besides, there was a quadratic effect (P < 0.05) for the recovery of dry matter, which ranged from 83.28 to 95.29%, with higher values observed for silage with the same proportions of soybean plant and sugarcane. It was verified that the crude protein content exhibited decreasing linear effects (P < 0.001), varying among 4.60 to 7.48% in the silages. It was concluded that the highest recovery of dry matter, the best fermentation profile, and the highest levels of crude protein and digestibility occurred in the inclusion between 25 and 50% of sugarcane in soybean silage, with the superiority of the C50 soybean genotype.

Use of by-products in a total mixed ration silage

The objective of this study was to evaluated fermentation losses and silage quality with the addition of different by-products in TMR. A completely randomized design was used with four treatments: Control (CTL, with hay, corn silage, cracked corn, soybean meal, wheat bran and minerals); CTL plus the addition of fresh orange pulp (FOP); CTL plus soybean hulls (SBH) or CTL plus wet brewery wastes (WBW), with six replicates. The ingredients were mixed and ensiled in 24 PVC experimental silos. After 56 days of ensiling, fermentation losses (effluents, dry matter and gases), and the TMR silage pH and chemical composition were analyzed; aerobic stability was evaluated over seven days after the silos were opened. Lower dry matter (P ? 0.0001) was observed in TMR ensiled with wet (WBW and FOP) compared to dry (SBH) by-products. Greater ADF (P = 0.031) was observed in SBH when compared to others by-products. WBW and FOP increased dry matter (P ? 0.0001) and effluent losses (P ? 0.0001) when compared to CTL and SBH. SBH treatment remained stable after 176-hour, which differ (P = 0.0015) compared with the other treatments (range from 94.5 to 99 hours of exposure to air). The density (kg DM/m3) changed (P ? 0.0001) among treatments. The inclusion of SBH in TMR silages had the greatest density, followed by CTL, WBW and FOP. The density was negatively correlated with DM losses ( r= - 0,81; P ? 0.0001). The pH differ (P = 0.003) among treatments. Highest pH of TMR silage was observed for SBH (3,67) and the lowest (3,56) for FOP. Soybean hulls successful improved aerobic stability and density, whereas aerobic stability and density were decreased and fermentation losses increased when fresh orange pulp and wet brewery were used. Little effects on chemical composition were observed, thereby agro-industrial by-products can be used in TMR silages as long as there is adequate product availability and pricing.

Effect of rehydration with whey and inoculation with Lactobacillus plantarum and Propionibacterium acidipropionici on the chemical composition, microbiological dynamics, and fermentative losses of corn grain silage

The objective of this study was to compare rehydrated corn grain silages using water or whey and inoculated (Lactobacillus plantarum and Propionibacterium acidipropionici) or not. We also verified whether rehydration with whey associated with the bacterial inoculant improves material conservation. The treatments were as follows: silages rehydrated with water without inoculant (SWa); silages rehydrated with water and inoculated (SWaI); silages rehydrated with whey without inoculant (SWe); silages rehydrated with whey and inoculated (SWeI). A completely randomized design was used, with three replications, treatments in a 2 × 2 factorial scheme (RE: rehydration with water or whey, and IN: inoculation or addition of water without chlorine), during the following storage periods (T): 0, 4, 8, 16, 32, and 64 days. There was an RE x IN x T interaction (P &lt; 0.001) for dry matter (DM), with lower values over time for SWe and higher values in SWeI. An interaction between RE x IN (P &lt; 0.001) and IN x T (P &lt; 0.001) was observed for pH, with higher values for SWe at 64 days of storage and a reduction from the first days of ensiling for SWaI and SWeI. The microbiological variables showed an RE x IN x T interaction (P &lt; 0.001), with the highest counts of lactic acid bacteria for SWaI and SWeI up to 8 days of storage and subsequent higher counts in SWa and SWe. Higher counts were obtained in SWe. For the variables of fermentative losses, there was an RE x IN x T interaction (P &lt; 0.001), with SWeI showing lower losses. The inoculation associated with whey for rehydration of corn grain improved the fermentation profile of the silage, with lower pH values and reduced losses.

Enhancement of biomass conservation and enzymatic hydrolysis of rice straw by dilute acid-assisted ensiling pretreatment

To reduce the cost of lignocellulosic pretreatment, rice straw was ensiled with dilute formic acid (FA, 0, 0.2, 0.4, and 0.6%) for 3, 6, 9, 15 and 30 days, and evaluated its effects on fermentation dynamics, lignocellulosic degradation and enzymatic hydrolysis. The results showed that the application of FA, especially at 0.6% level, reduced total fermentation losses of the resulting silages, as evidenced by low dry matter loss, ammonia nitrogen and ethanol content. Meanwhile, the 0.6% FA application promoted hemicellulose removal (232.41 vs 187.52 g/kg DM) and xylose production (0.35 vs 2.80 g/kg DM). The glucose yield and cellulose convertibility of rice straw increased after 30 days of ensiling, and further enhanced by the 0.6% FA application. In conclusion, the 0.6% FA-assisted ensiling pretreatment improved both biomass preservation, hemicellulose removal and enzymatic hydrolysis of rice straw, which is beneficial to the subsequent biofuel production chain.

Composição bromatológica da silagem de capim- elefante BRS Capiaçu com inclusão fubá de milho

The low dry matter content of forages (elephant grass) cv. BRS Capiaçu is one of the main factors responsible for the production of low nutritional value silage, the use of absorbent additives alleviates this problem. The objective was to evaluate fermentative losses and the quality of elephant grass (Pennisetum purpureum Schum) silage cv. BRS Capiaçu with different levels of cornmeal, with treatments (0, 5, 10, 15 and 20%) of corn. The analyzes were made at the Animal Nutrition Laboratory of the Federal Institute Sudeste Minas Gerais – Campus Rio Pomba, such as pH assessment, determination of nutritional values (ether extract, neutral detergent fiber, acid detergent fiber, crude protein). All analyzes that were made using specific scientific methodologies. The data were subjected to analysis of variance, with subsequent regression analysis and the means of each treatment will be evaluated using the Tukey test with 5% probability. The statistical analysis was carried out through the R Core Team Program with the aid of the technological package ExpDes.pt. There was a linear effect (P 0.05) with the addition of cornmeal for crude protein and ether extract. The use of cornmeal decreased gas losses, losses from effluents and significant dry matter recovery (P

Chitosan level effects on fermentation profile and chemical composition of sugarcane silage

This study aimed to evaluate the effects of increasing levels of chitosan (CHI) on sugarcane fermentation profile and losses, chemical composition, and in situ degradation. Treatments were: 0, 1, 2, 4, and 8 g of CHI/kg of dry matter (DM). Twenty experimental silos (PVC tubing with diameter 28 cm and height 25 cm) were used. Sand (2 kg) was placed at the bottom of each silo to evaluate effluent losses, and silos were weighed 60 d after ensiling to calculate gas losses. Samples were collected from the center of the silo mass to evaluate silage chemical composition, in situ degradation, fermentation profile, and mold and yeast count. Data were analyzed as a completely randomized design, and the treatment effect was decomposed using polynomial regression. Chitosan linearly increased acetic acid and NH3-N concentration, while yeast and mold count, and ethanol concentration decreased. Intermediary levels of CHI (from 4.47 to 6.34 g/kg DM) showed the lower values of effluent, gas, and total losses. There was a quadratic effect of CHI on the content of non-fiber carbohydrates, neutral and acid detergent, and in situ DM degradation. The lowest fiber content was observed with levels between 7.01 and 7.47 g/kg DM, whereas the highest non-fiber carbohydrate content and in situ DM degradation were found with 6.30 and 7.17 g/kg DM of CHI, respectively. Chitosan linearly increased acetic acid and NH3-N concentration, whereas it linearly reduced ethanol concentration and count of yeast and mold. Thus, intermediary levels of CHI, between 4.47 and 7.47 g/kg of DM, decrease fermentation losses and improve the nutritional value of sugarcane silage.

Caracterização bromatológica e perfil fermentativo de silagem de capim elefante misturada com ingredientes alternativos

Objetivou-se avaliar a composição bromatológica, perfil fermentativo e perdas fermentativas da silagem de capim elefante (CE) adicionado com diferentes níveis de palma forrageira (PF) e torta de semente de cupuaçu (TSC). Adotou-se o delineamento inteiramente casualizado (DIC), em esquema fatorial 2x3+2, com cinco repetições cada, totalizando 40 mini silos experimentais, com armazenamento por 50 dias. Avaliaram-se oito tratamentos, um composto somente por CE, um pool contendo 40% de CE, 30% de TSC e 30% de PF, enquanto os seis tratamentos restantes foram CE ensilado somente com TSC, ou com PF, ambas as misturas em níveis de 20, 40 e 60%. Após abertura, mensurou-se perdas de matéria seca (PMS), por gases (PG) e efluentes (PE). Determinou-se os parâmetros bromatológicos e o potencial hidrogeniônico (pH), realizou-se a determinação dos ácidos orgânicos e nitrogênio amoniacal. A estabilidade aeróbia foi determinada através da mensuração da temperatura nos tempos 0, 12, 24, 48, 72 e 96 horas pós abertura dos silos. Para a matéria seca ocorreu variação (P&lt;0,05) de forma quadrática, onde o pool e os tratamentos com inclusão de 40 e 60% de TSC obtiveram os maiores valores. A silagem somente com CE obteve o menor valor de pH (4,22). Concluiu-se que as perdas do CE foram minimizadas com a inclusão de 60% de TSC, enquanto o pool foi intermediário, tanto em termos bromatológicos quanto fermentativos.

Criteria for lactic acid bacteria screening to enhance silage quality.

The main challenge of ensiling is conserving the feed through a fermentative process that results in high nutritional and microbiological quality while minimizing fermentative losses. This challenge is of growing interest to farmers, industry and research and involves the use of additives to improve the fermentation process and preserve the ensiled material. Most studies involved microbial additives; lactic acid bacteria (LAB) have been the focus of much research and have been widely used. Currently, LABs are used in modern and sustainable agriculture because of their considerable potential for enhancing human and animal health. Although the number of studies evaluating LABs in silages has increased, the potential use of these micro-organisms in association with silage has not been adequately studied. Fermentation processes using the same strain produce very different results depending on the unique characteristics of the substrate, so the choice of silage inoculant for different starting substrates is of extreme importance to maximize the nutritional quality of the final product. This review describes the current scenario of the bioprospecting and selection process for choosing the best LAB strain as an inoculant for ensiling. In addition, we analyse developments in the fermentation process and strategies and methods that will assist future studies on the selection of new strains of LAB as a starter culture or inoculant.

Nutritional value, fermentation losses and aerobic stability of elephant grass (Pennisetum purpureum Schum.) silage treated with exogenous fibrolytic enzymes

The aim of this study was to evaluate nutritional value, fermentation losses, and aerobic stability of elephant grass silage (Pennisetum purpureum Schum.) treated with exogenous fibrolytic enzymes. The experiment was conducted in a completely randomized design with four replicates (experimental silos) and five levels of fibrolytic enzymes (0, 1.5, 3.0, 4.5 and 6.0%). For this, the elephant grass was ensiled at 70 days of age in plastic buckets with 20L capacity. Silos were opened 60 days after sealing. Analyses were made for chemical composition, in vitro dry matter digestibility (IVDMD), effluent losses (EL), gas losses (GL) and dry matter recovery (DMR), as well as the aerobic stability of the silage. Data were analyzed with PROC REG of SAS® University, at 5% probability. There was an increase in IVDMD content (p &lt; 0.0001) and reduction in NDF and ADF contents (p &lt; 0.0001) according to enzyme levels. These results were related to the increase in the degradation of fiber fractions. There were higher EL (p = 0.0062) as a function of enzyme levels and aerobic deterioration after silo opening, at all levels tested. Thus, it can be concluded that the exogenous fibrolytic enzymes change the chemical composition of elephant grass silage, and increase its digestibility and nutritional value. Moreover, when used alone as an additive, fibrolytic enzymes are not able to recover all dry matter of this silage (with effluent and gas losses), and are not able to maintain aerobic stability in the first hours after opening the silos.

Effects of inclusion of patauá, Oenocarpus bataua meal on elephant grass silage

ABSTRACT Elephant grass silages have high moisture content, causing nutrient loss, mainly by effluent production. The use of moisture absorbent additives, such as patauá, Oenocarpus bataua meal, can be a strategy to reduce losses in these silages. The aim of this study was to determine the fermentation losses, microbiological composition, fermentative characteristics, and chemical composition of elephant grass silage with increasing levels of inclusion of patauá meal. The experiment was conducted in a completely randomized design, with four concentrations of patauá meal (7%, 14%, 21%, and 28%, based on fresh matter) and a control without patauá, and five replicates. The elephant grass was collected manually after 60 days of growth. After chopping, the grass was homogenized, mixed with the patauá meal according to the established treatments, and ensiled in experimental silos of 15 L. The inclusion of patauá meal in elephant grass silage had positive effects on the chemical composition and effluent loss. It significantly increased dry matter, organic matter, crude protein, nitrogen insoluble in neutral detergent and acid, ethereal extract, lignin, and non-fibrous carbohydrates of the silages. It also reduced effluent losses, neutral and acid detergent fiber contents, and cellulose. Our findings contribute towards reducing the environmental impact caused by the production of effluents during ensilage of tropical grasses and providing a potential use for the residue from the production of patauá oil, thus avoiding disposal in the environment.

Cassava peel ensiling with tomato waste submitted to dehydration: fermentative losses and chemical composition.

The aim of this study was to evaluate the effect of different dehydration times of the tomato waste (0, 4, 24, 60 and 96 hours) added in the cassava peel silages on the density, fermentative losses, dry matter recovery, chemical composition, and sensorial quality. The material was ensiled for 60 days in polyvinyl chloride (PVC) silos. There was a linear reduction of 0.406 kg tonne-1 of fresh matter in the effluent production in the silages. A maximum dry matter (DM) loss (p<0.01) of 7.00% was found with 8.10 h of dehydration of the tomato wastes. There was a quadratic behavior (p<0.01) for crude protein (CP) and non-fibrous carbohydrates (NFC), with minimum content of 9% CP and maximum content of 66.0% NFC with 3.53 h and 7.35 h of dehydration of the tomato wastes, respectively. The satisfactory classification was observed to the silages with 4, 24 and 96 h of dehydration of tomato waste in the sensory evaluation of the characteristics associated with the nutritional value. Cassava peel ensiling with tomato waste submitted to dehydration time of 7.35 hours is enough to promote an adequate non-fibrous carbohydrates content, associated with lower losses in the fermentation process.

Mixed silages of cactus pear and gliricidia: chemical composition, fermentation characteristics, microbial population and aerobic stability

The present study aimed to evaluate the chemical composition, profile and fermentative losses, microbial population and the aerobic stability of mixed silages of cactus pear and gliricidia. The treatments corresponded to the addition levels of gliricidia (Gliricidia sepium (Jacq.) Steud), in the silages of cactus pear (Opuntia ficus indica Mill.), at ratios 0%, 25%, 50%, 75% and 100% gliricidia. The data were subjected to analysis of variance and regression to evaluate the effect of the addition levels of gliricidia. The average related to the opening days were compared by the Tukey’s test and the average hours of exposure to air were compared by the Student’s t-test. The addition of gliricidia in cactus pear silage provided a linear increasing effect for pH, crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL), neutral detergent insoluble protein (NDIP), and increased aerobic stability (AS). The highest dry matter recovery was estimated in the silages with 58% gliricidia. Based on the fermentative, chemical composition and silage losses, all the silages tested were adequate. However, considering aerobic stability, the addition of at least 25% gliricidia is recommended to provide the animal a feed with important quality and high nutritional value.

Effect of Whey Permeate and Lactobacillus buchneri on Biomass Conservation, Chemical Characteristics and Aerobic Stability of Elephant Grass Silage

This study was carried out to evaluate the effect of whey permeate, bacterial inoculant and periods of fermentation and aerobic exposure on some characteristics of Pennisetum purpureum silage. The experimental design was completely randomized with three factors: whey permeate (0, 25, 50 and 100 g kg−1 of fresh matter—FM), bacterial inoculation with Lactobacillus buchneri (inoculated or non-inoculated), and periods of fermentation (from 1 to 35 days) or aerobic exposure (from 0 to 15 days). Cumulative losses increased sharply up to 14 days, but relative losses persisted up to 21 days in silage with 100 g kg FM−1 of permeate. The addition of permeate reduced neutral detergent fiber by between 16.2% (non-inoculated) and 17% (inoculated), and increased non-fibrous carbohydrates by between 66% (non-inoculated) and 79.3% (inoculated) during fermentation. Carbohydrate fractions followed opposing trends with air exposure, particularly up to 9 days of aerobiosis. Around 9 days of aerobiosis, the pH had the greatest increase (3.7 to 6.8), with NH3-N increasing after that time. L. buchneri increased aerobic stabilization, but higher levels of permeate increased temperature changes. Permeate must be used at 25 g kg−1 of fresh matter to increase the energy status of Elephant grass silage while providing substrate for fermentation and reducing fermentative losses. The best performance of this level of permeate should also be associated to L. buchneri for effective preservation of nutrients and to keep the aerobic stability of high-moisture Elephant grass silage, being indicated to improve silage conservation.

Efeito do Tempo de Ensilagem sobre a composição química, perfil Fermentativo e Estabilidade Aeróbia de Silagens de Milho (Zea mays)

A silagem de milho é amplamente utilizada, devido a sua qualidade nutricional, produção de matéria seca por ha-1 e bom padrão fermentativo. Objetivou-se avaliar o efeito do tempo de ensilagem sobre o padrão fermentativo, qualidade nutricional, perdas e estabilidade aeróbia de silagens de milho (Zea mays). Empregou-se um delineamento experimental inteiramente casualizado, com quatro tratamentos (0; 12; 24 e 48h para ensilagem após o corte da forrageira) e cinco repetições. Após 30 dias de fermentação foram determinadas as perdas por efluentes, perdas por gases e recuperação de matéria seca. Para o ensaio de estabilidade, foram retiradas aproximadamente 2kg de silagem de cada unidade experimental e adicionadas em recipientes plásticos com capacidade de 4 litros, foram aferidas a temperatura (intervalo de 2 horas), pH e condutividade elétrica (intervalo de 6 horas) Realizou-se a determinação de nitrogênio amoniacal, capacidade tamponante e dióxido de carbono. A composição química-bromatologica, avaliou-se os teores de matéria seca, matéria mineral, extrato etéreo, proteína bruta, matéria orgânica, fibra em detergente neutro e ácido, carboidratos totais, carboidratos não fibrosos, proteína insolúvel em detergente neutro e ácido e hemicelulose. Todos os resultados foram submetidos a teste de regressão a 5% de probabilidade. O período de ensilagem não influenciou as perdas fermentativas para as perdas por gases e recuperação de matéria seca. O padrão químico da silagem não teve alteração para o teor de proteína bruta com médias de 84,60g; 78,26g; 82,58g e 74,22g, respectivamente para os tratamentos 0h; 12h; 24h e 48h. O tempo de ensilagem após o corte altera a dinâmica de produção de carbono, aumenta o teor de nitrogênio amoniacal, reduz a capacidade tamponante e diminui a estabilidade da silagem.

Lemongrass essential oil in sugarcane silage: Fermentative profile, losses, chemical composition, and aerobic stability

Essential oils have been used to manipulate microbial growth in different processes such as silage fermentation. This study aimed to evaluate the effects of increasing levels of lemongrass oil (LO) in sugarcane ensiling on fermentative profile and losses, chemical composition, in vitro degradation, and aerobic stability. Thirty-two experimental silos were used in a blocked randomized design to evaluate the following treatments: control (CON), sugarcane ensiling without LO; and increasing levels of LO on sugarcane ensiling: 1 (L1), 2 (L2), and 3 (L3) mL of LO per kg of sugarcane (as-fed basis). Results of LO level effects were regressed to access the maximum/minimum points. Lemongrass oil linearly increased NH3-N and decreased the count of mold and yeast, lactic, and butyric acid concentrations. Besides, LO quadratically affected silage pH, Brix, and levels of ethanol and acetic acid. The lowest silage pH, ethanol, and acetic acid concentration were found with 1.17, 2.22, and 1.89 mL/kg of LO. Lemongrass oil quadratically affected fermentative losses, dry matter (DM) recovery, and chemical composition of silage. The lowest total losses were found at 1.53 mL/kg of LO, whereas the highest DM recovery was obtained using 1.90 mL/kg LO. Intermediary levels of LO (1.99–2.00 mL/kg) improved silage DM, organic matter, non-fiber carbohydrate, and ether extract content, whereas reduced silage concentration of neutral detergent fiber, acid detergent fiber, lignin, and crude protein. Lemongrass oil did not affect neutral detergent fiber in vitro degradation and quadratically affected DM degradation of silage, whereas linearly increased silage aerobic stability (h) and temperature of silage between 48 and 104 h after aerobic exposure. Thus, intermediary levels (between 1.53 and 2.22 mL/kg) of LO reduces ethanol concentration and fermentative losses of silages, improving DM recovery, chemical composition and DM degradation of sugarcane silage. Additionally, LO levels linearly decrease yeast and mold count and increase the aerobic stability of sugarcane silage.