ABSTRACT This study aimed to determine the effects of relocation time (RT; Experiment 1) and storage time after relocation (ST; Experiment 2) on microbial population, fermentative characteristics, and chemical composition of corn silage. In experiment 1, corn silage was stored for 30 d, subjected to different RT (0–60 h), and stored again for 30 d. Thirty experimental silos were used in a completely randomized design, with three replicates per treatment. In experiment 2, after 150 d of ensiling, silage was removed from a bunker silo, exposed to air for 9 h, relocated to experimental silos, and stored for periods ranging from 0 to 128 d. Twenty-eight experimental silos were used in a completely randomized design, with four replicates per treatment. Relocation time had no effect on fungi counts and concentrations of lactic and propionic acids in corn silage but resulted in a significant increase in dry matter content. In experiment 2, dry matter recovery and concentration of non-fiber carbohydrates decreased in corn silage stored for more than 32 d after relocation. Exposure of corn silage to air during relocation for up to 60 h followed by 30 d of storage did not compromise the fermentation profile or nutritive value of the silage. Increased storage time of relocated corn silage (up to 128 d) consistently decreases its nutritional value. The storage period seems to have an increased impact on nutrient loss in relocated silage than the relocation period.

Resumo O objetivo do estudo foi avaliar composição química, perfil fermentativo, população de microrganismos e recuperação de matéria seca (RMS) de silagem de cana-de-açúcar contendo níveis crescentes (0, 25, 50 e 75%, na base da matéria natural) de amendoim forrageiro (Arachis pintoi cv. Belmonte), tratadas ou não com Lactobacillus buchneri. Usou-se o esquema fatorial 4×2, no delineamento inteiramente casualizado, com três repetições. Verificou-se efeito de interação níveis de amendoim forrageiro e inoculante para teores de matéria seca, proteína bruta, fibra em detergente neutro e ácido, ácidos orgânicos e etanol, população de bactérias láticas e leveduras, perdas por gases e por efluente e RMS. Houve efeito de níveis de amendoim forrageiro no teor de hemicelulose, nitrogênio insolúvel em detergente ácido, pH e nitrogênio amoniacal. Verificou-se que o aumento de níveis de amendoim forrageiro incrementou teor de proteína e diminuiu teor de fibra, além de reduzir a produção de etanol e de efluente. Recomenda-se inclusão de 40% a 75% de amendoim forrageiro na ensilagem de cana-de-açúcar para melhorar a composição química e o perfil de fermentação. A inoculação com L. buchneri associada ao amendoim forrageiro aumenta a concentração de ácidos antifúngicos na silagem e decresce a população de leveduras e a produção de etanol.

Abstract There is evidence for the beneficial effects of forage peanut on the nutritive value and fermentation profile of silages; however, its effects on sugarcane silage have not been determined. The objective of the study was to evaluate the chemical composition, fermentation profile, microbial composition, and dry matter recovery (DMR) of sugarcane silage containing various amounts of forage peanut (Arachis pintoi cv. Belmonte) (0%, 25%, 50%, and 75% on a fresh matter basis), treated or untreated with Lactobacillus buchneri. A completely randomized 4 × 2 factorial design was used with three replications. The interaction between forage peanut levels and inoculant influenced the concentrations of dry matter, crude protein, neutral detergent fiber and acid detergent fiber, organic acids and ethanol, populations of lactic acid bacteria and yeast, gas and effluent losses, and DMR. Forage peanut levels had effects on dry matter, hemicellulose, acid detergent insoluble nitrogen, pH, and ammonia nitrogen. Increasing proportions of forage peanut increased the protein content and decreased the fiber content in the silage, while also reducing the production of ethanol and effluent. We recommend the inclusion of 40%–75% forage peanut in the sugarcane ensilage to improve the chemical composition and fermentation profile. Furthermore, inoculation with L. buchneri associated with forage peanut increases the concentration of antifungal acids in the silage and decreases the yeast population and ethanol production.

RESUMO O uso da silagem de raiz de mandioca na alimentação animal representa uma opção viável tanto para os produtores que cultivam mandioca (visando ter um produto para comercialização alternativa), quanto para os pecuaristas que compram milho a preços elevados. Assim, objetivou-se determinar o efeito de variedades e da correção da acidez do solo sobre as populações microbianas, características fermentativas, composição química, estabilidade aeróbia e perdas de silagens de raízes de mandioca. O experimento foi conduzido em delineamento em blocos casualizados, em arranjo fatorial 2×3 com quatro repetições. Foram avaliados dois genótipos de mandioca (Caeté e Manteiguinha) e três tipos de correção de acidez do solo (calagem, gessagem e calagem+gessagem). Após 11 meses, as raízes foram colhidas, trituradas e ensiladas em silos do tipo PVC, onde permaneceram por 45 dias. Não observamos efeito de interação entre genótipos e correção do solo para os parâmetros testados. As silagens do genótipo Caeté apresentaram as maiores concentrações de matéria seca (421 g kg-1 matéria fresca) e carboidratos não fibrosos (893 g kg-1 matéria seca), e menores de fibra em detergente neutro (37.1 g kg-1 matéria seca). Não houve diferenças significativas entre tratamentos para bactérias ácido láticas, leveduras e mofos nas silagens. Ambos os genótipos resultaram em silagens com perfil de fermentação adequado e estabilidade aeróbia consideravelmente elevada, mas com elevadas perdas de efluentes. O genótipo Caeté apresentou condições potencialmente melhores para produção de silagem devido a sua maior recuperação de matéria seca. Devido à alta perda de efluente, recomendamos testar o efeito da adição de um aditivo absorvente de umidade durante o processo de ensilagem dessas raízes de mandioca.

ABSTRACT The use of cassava root silage for animal feeding is a suitable option for farmers who grow cassava as an alternative product and for cattle ranchers who have to deal with high prices of corn. Our objective was to determine the effects of cassava genotypes and the correction of soil acidity on the microbial population, fermentation characteristics, chemical composition, aerobic stability and losses of cassava root silage. We used a 2 × 3 factorial design in completely randomized blocks, with four replications. We evaluated two cassava genotypes (Caeté and Manteiguinha) and three methods of soil acidity correction (lime, gypsum, and lime+gypsum). The roots were harvested 11 months after planting, ensiled in PVC silos, and stored for 45 days. No interaction was observed between genotypes and soil acidity correction for any of the evaluated parameters. The silage of Caeté genotype showed the highest concentration of dry matter (421 g kg-1 fresh matter) and non-fibrous carbohydrates (893 g kg-1 dry matter), and the lowest concentrations of neutral detergent fiber (37.1 g kg-1 dry matter) . No significant differences were observed among treatments for lactic acid bacteria, yeast and mold counts in silages. Both genotypes resulted in silages with an adequate fermentation profile and considerably high aerobic stability, but with high effluent loss. The Caeté genotype showed to be potentially better for silage production due to its higher dry matter recovery. Due to the high level of effluent loss, it is recommended to test the effect of a moisture-absorbing additive during the ensiling process of these cassava roots.

RESUMO As silagens de capim elefante têm alto teor de umidade, que ocasiona perda de nutrientes, principalmente pela produção de efluentes. O uso de aditivos absorventes de umidade, como a torta de patauá, Oenocarpus bataua, pode ser uma estratégia para reduzir as perdas nessas silagens. Assim, objetivou-se determinar as perdas fermentativas, composição microbiológica, características fermentativas e composição química em silagens de capim elefante com níveis crescentes de inclusão de torta de patauá. O experimento foi conduzido em delineamento inteiramente casualizado, com quatro concentrações de torta de patauá (7%, 14%, 21% e 28%, com base na matéria natural) e um controle sem patauá, e cinco repetições. O capim elefante foi coletado aos 60 dias de crescimento. Após o corte, o capim foi homogeneizado, misturado com a torta de patauá de acordo com os tratamentos estabelecidos, e ensilado em silos experimentais de 15 L. A inclusão da torta de patauá em silagens de capim elefante teve efeitos positivos sobre a composição química e as perdas por efluentes. Houve aumento significativo de matéria seca, matéria orgânica, proteína bruta, nitrogênio insolúvel em detergente neutro e ácido, extrato etéreo, lignina e carboidratos não fibrosos das silagens. Além disso, houve redução de perdas por efluentes, teor de fibra em detergente neutro e ácido, e celulose das silagens. Nossos resultados contribuem para a redução de impactos ambientais gerados pela produção de efluentes no processo de ensilagem de gramíneas tropicais e fornecem uma utilidade potencial para o resíduo da produção de óleo de patauá, evitando o descarte no meio ambiente.

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.

ABSTRACT In this study, we aimed to determine the effects of cutting height (25 or 40 cm above ground) and bacterial inoculation (a combined inoculant of Lactobacillus plantarum and Propionibacterium acidipropionici) on the chemical and microbial compositions, fermentative profile, and aerobic stability of whole-plant corn silage and nitrogen balance, intake, and apparent nutrient digestibility by sheep. To evaluate silage characteristics and sheep metabolism, we performed analyses based on a completely randomized block design with a 2×2 factorial arrangement (two cutting heights, with or without bacterial inoculant). We evaluated the chemical and microbial compositions, pH, fermentation end-products, and aerobic stability of silage. To examine nutrient digestibility of silage, we used 24 male sheep over a 21-day period. We found that the aerobic stability did not differ among the silages. Sheep fed silages produced from corn harvested at 40 cm had increased intakes of crude protein, non-fiber carbohydrate, and total digestible nutrients, whereas the non-fiber carbohydrate intake of inoculated corn silages was found to be higher than that of uninoculated silage. Furthermore, the amounts of nitrogen retained by sheep fed silage produced from corn harvested at 40 cm were higher than those of sheep fed silage produced from corn harvested at 25 cm. Collectively, our findings indicate that, despite the observed effects, a difference of 15 cm in cutting height results in relatively small changes in the chemical composition of corn silage and a limited effect on the nutrient intake and nitrogen balance of animals fed this silage. Moreover, although bacterial inoculation promotes an efficient fermentation, it has no marked effects on the aerobic stability of silage.

The present study evaluated the microbial population, fermentation profile, losses and dry matter recovery, and chemical composition of silages of buffel grass at different cutting heights. To evaluate the microbial fermentation dynamics, the treatments resulted from a 4 × 5 factorial combination consisting of 4 cutting heights and 5 fermentation periods, in a completely randomized design with three replications. The fermentation was evaluated at the end of 1, 3, 7, 15 and 30 days. The other characteristics of silages with 30 days were evaluated following a completely randomized design with four treatments, consisting of 4 cutting heights (30, 40, 50 and 60 cm), and five replications. Fermentation period and cutting height effects and interaction between both factors were observed on the populations of lactic acid bacteria (LAB), enterobacteria and molds and yeasts. The peak of development of LAB populations was observed on the seventh day of fermentation for the heights of 40 and 50 cm, with 8.25 and 8.30 log cfu/g, respectively. The pH values of silages ranged with different cutting heights, in which at the height of 50 cm the decrease was most pronounced. However, the pH values were similar between the cutting heights at the end of 30 days of fermentation. Quadratic relationship was observed between lactic acid concentrations and cutting heights. The crude protein content behaved linearly, initially showing 128.5 g/kg DM at 30 cm, decreasing as the cutting heights increased. The neutral detergent fiber and ether extract contents increased linearly with the cutting heights. Based on microbial populations, fermentation, losses and chemical composition, it is recommended to harvest buffel grass for silage from 50 cm on.

Objetivou-se quantificar o rendimento forrageiro, o percentual de componentes da planta, as características morfométricas e a eficiência do uso da chuva de cinco genótipos de sorgo para silagem no semiárido paraibano. O experimento foi conduzido na Estação Experimental Pendência, no município de Soledade-PB. O delineamento experimental utilizado foi em blocos casualizados, com quatro repetições, sendo os tratamentos experimentais representados por cinco genótipos de sorgo: Ponta Negra, SF 15 IPA 1011, IPA 2502 e IPA 46742. Não foram observadas diferenças entre os genótipos para a produção de matéria natural e produção de matéria seca e para o percentual de lâmina foliar. Entretanto, para o percentual de colmo foram observados maiores valores (P<0,05) para os genótipos Ponta Negra e IPA 46742. O percentual de panícula foi superior (P<0,05) para as cultivares 'IPA 1011' e 'IPA 2502'. As cultivares 'IPA 1011' e 'IPA 2502' apresentaram percentual de panícula acima de 38% da MS. Não houve diferença (P<0,05) para eficiência no uso da água de chuva entre os genótipos estudados, com valores variando de 94,37 a 126,25kg de MS ha-1 mm-1. Os genótipos avaliados apresentam elevada eficiência no uso da chuva e produtividade. Recomenda-se o IPA 1011 pela maior participação de panícula.

The objective was to quantify the forage yield, percentage of plant components, the morphometric characteristics and the rain use efficiency of five genotypes of sorghum silage in semiarid of Paraiba. The experiment was conducted at the Experimental Station Pendência, municipality ofSoledade-PB. The experimental design used was randomizedblocks with four replicates, being experimental treatments represented by five sorghum genotypes: Ponta Negra, SF 15 IPA 1011, IPA 2502 and IPA 46742. No differences had been observed between genotypes for the production of natural matter and dry matter production. For the percentage of leaf blade was not significant difference (P>0.05), however for the percentage of stem showed higher (P<0.05) for genotypes Ponta Negra and IPA 46742. The percentage of panicle was high (P<0.05) for cultivars 'IPA 1011' and 'IPA 2502'. The cultivars 'IPA 1011' e 'IPA 2502' showed panicle percentage above 38% DM. There was no difference (P<0.05) in rain-use efficiency among genotypes, with values ranging from 94.37 to 126.25kg DM ha-1 mm-1. The genotypes showed high use efficiency of rain can and productivity, which is recommended by the IPA 1011 increased participation panicle.

Objetivou-se avaliar as características morfogênicas e a produção de fitomassa do capim buffel (Cenchrus ciliaris cv. Molopo) adubado com diferentes quantidades de digesta bovina sólida. Utilizou-se uma área experimental de dois hectares de pastagem de capim buffel implantados em 2006 sendo esta área destinada exclusivamente para a produção de feno. No ano de 2009 o experimento foi implantado em uma área total de 375m², que foi dividida em 25 parcelas de 15m² cada, sendo que cada parcela possuía 8m² (4x2) de área experimental e uma linha de bordadura de 0,5m de largura em torno do seu perímetro. Foi utilizado o esquema de parcelas subdivididas no tempo, em delineamento experimental de blocos completos ao acaso, com cinco tratamentos e cinco repetições correspondentes às quantidades de digesta bovina (3,5; 7,0; 10,0 e 13,5 t/ha), totalizando 25 unidades experimentais. Houve interação entre as quantidades de digesta e os cortes para a produção de fitomassa verde, sendo que para todas as quantidades de digesta aplicadas foram obtidas maiores produções para o terceiro corte. A maior produção de fitomassa verde foi obtida para o tratamento com 13,5t/ha de digesta. Não houve interação entre cortes e adubação com digesta para o número de perfilhos vivos, número de perfilhos mortos, número de folhas vivas por perfilhos, filocrono, altura e diâmetro de touceira. Dessa forma, recomenda-se a aplicação de digesta bovina por ser eficiente em aumentar a produção de fitomassa do capim buffel cv. Molopo.

The objective was to evaluate the morphogenesis and the production of biomass of buffel grass fertilized with different amounts of bovine solid digesta. We used an experimental area of two hectares of grazing buffel grass (Cenchrus ciliaris cv. Molopo) deployed in 2006, this area is designed exclusively for the production of hay. In 2009 the experiment was implemented a total area of 375m², which was divided into 25 plots of 15m² each, with each plot had 8m² (4x2) of the experimental area and a boundary line of 0.5m wide around the perimeter. We used a split-plot in time, in randomized complete block experimental design, with five treatments and five repetitions of the corresponding amounts of bovine digesta (3.5; 7.0; 10.0 and 13.5t/ha), totaling 25 experimental units. There was interaction between the amounts of digesta and cuts for the production of green biomass, and for all quantities of digesta were obtained higher yields applied to the third cut. The largest green biomass production was obtained for treatment with 13.5t/ha of digesta. There was no interaction between cuts and fertilization with digesta to the number of live tillers, number of dead tillers, number of live leaves per tiller, phyllochron, height and diameter of clump. Thus, it is recommended the application of bovine digesta to be efficient in increasing the production of biomass of buffel grass cv. Molopo, through changes in some structural features, can be used as organic fertilizer in pastures of grass.

Dois experimentos foram conduzidos com o objetivo de avaliar o perfil fermentativo e a composição bromatológica de silagens de sorgo. No experimento 1, avaliou-se o perfil fermentativo do sorgo em resposta à adubação nitrogenada, em delineamento inteiramente casualizado, em parcela subdividida 5 x 6 (cinco doses de nitrogênio e seis períodos de abertura). As doses de adubação nitrogenada foram: 0; 50; 100; 150 e 200kg/ha e os períodos de abertura foram: 1; 3; 7; 14; 28 e 49 dias. No experimento 2 avaliaram-se as variações nos constituintes bromatológicos do sorgo. O delineamento experimental utilizado foi em blocos casualizados com cinco repetições, e os tratamentos tiveram os mesmos níveis de adubação do experimento 1. Os teores de matéria seca aumentaram linearmente com as doses de nitrogênio e com o período de fermentação. O pH aumentou linearmente em função da adubação nitrogenada e apresentou resposta quadrática em função do período de fermentação. Os valores de N-NH3 apresentaram resposta quadrática, tanto a doses de nitrogênio, quanto dos dias de abertura. A matéria orgânica aumentou linearmente e a matéria mineral reduziu. Lignina respondeu de forma linear crescente ao incremento da adubação nitrogenada. Os teores de hemicelulose reduziram linearmente. Os valores de matéria seca, pH e amônia demonstraram eficácia no processo fermentativo da silagem, independente da quantidade de nitrogênio utilizado. A utilização da adubação é uma prática interessante, pois aumenta a produtividade da planta sem alterar a composição bromatológica da silagem.

Two experiments were conducted to evaluate the fermentation characteristics and chemical composition of sorghum silage. In the first experiment the fermentative profile of sorghum silages in response to nitrogen fertilization was evaluated using a completely randomized design, in split-plot scheme with five doses of nitrogen (in the plot) and six opening times (in the subplot). The nitrogen levels were 0; 50; 100; 150 and 200kg/ha and the opening times were: 1; 3; 7; 14; 28and 49 days after ensiling. In the second experiment the variations in the chemical composition of sorghum silages was evaluated. The experimental design was randomized blocks with five repetitions, and the treatments consisted on the same levels of fertilization of first experiment. Dry matter increased linearly with the nitrogen and the fermentation period. The pH increased linearly as a function of nitrogen and showed a quadratic response as a function of fermentation period. The N- NH3 values showed a quadratic response both to nitrogen as for the opening day. Organic matter increased linearly and mineral matter decreased. Lignin responded linearly to increasing nitrogen fertilization. The hemicellulose decreased linearly. The dry matter, pH and ammonia values show efficacy in the silage fermentation process independent of nitrogen level used. The use of fertilizer is an interesting practice, which increases plant productivity without changing the chemical composition of the silage. Nevertheless, for the most economic treatment, is indicated the use of 150kg of nitrogen per hectare.

The objective of this study was to evaluate the divergence of bromatological and fermentative characteristics of silages of 25 sorghum (Sorghum bicolor L. Moench) hybrids. The experimental design was completely randomized with 25 treatments and four replications. The mean values of pH differed with variation from 3.45 to 3.87 for hybrids 866005 and 870051, respectively, and the mean pH value was 3.66. The average percentage of lactic acid ranged from 2.90 to 7.43 dag/kg of dry matter (DM) in hybrids 870035 and 866005, respectively, with an average of 4.65 dag/kg DM. Through cluster analysis by the Tocher method and average Euclidean distance based on the fermentative characteristics, five groups were formed: one with 18 hybrids, another with four and three groups with one hybrid in each. In group three, there were the hybrids that showed the highest values of lactic acid. Hybrids 870025, 870035, 870081, 870095, 866034, and 870031 showed higher DM content and the hybrid BRS 610 had the lowest average compared with the others. Hybrids 1F305, BRS 610, Volumax, and XBS60329 had the lowest levels of non-fiber carbohydrates and higher neutral detergent fiber corrected for ash and protein. Despite the fermentative and bromatological divergences between hybrids, they are not a limiting factor to silage production.

The objective of this study was to evaluate the whey fermented by Enterococcus faecium in consortium with Veilonella parvula on the in vitro growth of ruminal bacteria and as a supplement in the cattle diet. In the in vitro experiment, a randomized design, with the following combinations was used: ruminal bacteria; ruminal bacteria and inactive whey; ruminal bacteria and active whey; and active whey. In the in vivo experiment, five fistulated Zebu Holstein-Zebu crossbred heifers were distributed in a 5 × 5 Latin square. Supplements were formulated without the addition of whey, with the addition of two levels of unfermented whey (2.5 and 5 L/day) or two levels of fermented whey (2.5 and 5 L/day). A positive effect of the whey fermentation was detected on the consumption of dry matter, organic matter, crude protein, ether extract, non-fiber carbohydrates and neutral detergent fiber, corrected for ash and protein in kg/day. No effects of whey were observed on the pH and concentration of rumen ammonia nitrogen, serum concentration of urea and glucose, urinary excretion of urea or nutrient digestibility, except for the total digestible nutrients. Supplementation with whey improved the apparent nitrogen balance, but supplementation with fermented whey decreased the intestinal flow of microbial nitrogen and microbial synthesis efficiency in relation to the unfermented whey. The whey fermentation process does not optimize the physiological responses of heifers supplemented with 2.5 and 5.0 L of whey.

The objective of this study was to evaluate the agronomic divergence of 25 sorghum hybrids (Sorghum bicolor L. Moench) in the semiarid region of Paraiba. A randomized block design with three replications was used for evaluation of plant height (PH), total natural matter production (TNMP) and total dry matter production (TDMP) and the percentage of components of DM (panicle, leaf blade, stem and dead matter) of the following hybrids: 866005, 866019, 866033, 866034, 866035, 866036, 866037, 866040, 866041, 866042, 866043, 866044, 870025, 870031, 870035, 870041, 870051, 870067, 870081, 870085, 870095, 1F305, BRS 610, Volumax, and XBS60329. Hybrid 1F305, followed by hybrid 866034, presented the highest average PH. There was a range from 7.679 to 20.948 kg/ha (average of 13,799 kg/ha) for TDMP. Hybrids 1F305, BRS 610 and Volumax presented less potential, and hybrids 866,041 and 866,042 were the most productive. Based on cluster analysis and subjective cut in 50% of dissimilarity, it was possible to establish four hierarchical groups, from which two stood out concerning productive characteristics. The group formed by hybrids Volumax, BRS 610, and XBS60329 presented lower averages for yield and lower percentage of panicle. Hybrids 866041 and 866042 show a higher total dry matter production, with values around 20,000 kg/ha.

Objetivou-se com este experimento avaliar os efeitos da adição de raspa de mandioca na ensilagem sobre as perdas por gases e efluentes, a recuperação da matéria seca, o pH, os teores de N-NH3, ácidos orgânicos e ácidos graxos voláteis e a composição bromatológica de silagens de capim-elefante. Utilizou-se um delineamento inteiramente casualizado, com quatro níveis de raspa de mandioca (0, 7, 15 ou 30% da matéria natural), cada um com quatro repetições. O capim foi cortado aos 50 dias de rebrota e ensilado em silos de 15 litros de capacidade, com válvula de bunsen para escape dos gases. A adição de raspa de mandioca ocasionou redução quadrática nas perdas por gases e redução linear nas perdas por efluente. A recuperação de matéria seca aumentou de forma quadrática com a adição de raspa de mandioca. O teor de matéria seca aumentou, enquanto os de proteína bruta, fibra em detergente neutro, fibra em detergente ácido (FDA) e hemicelulose diminuíram linearmente com a adição de raspa de mandioca. O valor de pH e o teor de ácido lático aumentaram de forma quadrática com a adição de raspa de mandioca. Os teores de N-NH3 e de ácido butírico diminuíram de forma quadrática com a adição de raspa de mandioca, enquanto o teor de ácido acético diminuiu linearmente. A inclusão de raspa de mandioca na ensilagem reduz as perdas por gases e efluentes e melhora o perfil fermentativo de silagens de capim-elefante e o nível de 7% da matéria natural é suficiente para assegurar essa melhora.

The objective of this experiment was to evaluate the effects of adding cassava scrapings on gas and effluent losses, dry matter recovery, pH, contents of N-NH3, organic acids and volatile fatty acids and the bromatological composition of elephant grass silages. It was used a randomized complete design, with four levels of cassava scrapings (0, 7, 15 or 30% natural matter) each one with four replications per level. The grass was cut at 50 days of regrowth and ensiled in 15-L silos, equipped with a Bunsen valve to allow gas outflow. The gas losses decreased quadratically with the addition of cassava scrapings, whereas effluent losses decreased linearly. Dry matter recovery increased quadratically with the addition of cassava scrapings. Dry matter (DM) concentration increased but crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and hemicellulose (HEM) decreased linearly with the addition of cassava scrapings. The pH value and lactic acid concentration increased quadratically with the addition of cassava scrapings. Contents of N-NH3 and butyric acid decreased quadratically with the addition of cassava scrapings, whereas acetic acid content decreased linearly. Addition of cassava scrapings reduced gas and effluent losses and improved the fermentation profile of elephant grass silages and the level of 7% already ensures this improvement.