-Microbial populations, pH, ammonium nitrogen/total nitrogen (N-NH 3 ) ratio, concentrations of lactic acid, acetic acid and butyric acid and the chemical composition of Brachiaria decumbens cv. Basiliski silages at different regrowth ages (30, 40, 50, 60 and 70 days) were evaluated by using 2-kg capacity laboratory silos. It was used a 5 × 6 factorial scheme (5 regrowth ages × 6 fermentation periods) in a complete random design, with three replicates. The fermentation periods were 1, 3, 7, 14, 28 and 56 days. Lactic acid bacteria populations were recorded in fresh forage varying from 3.93 (30 days of regrowth) to 5.51 (70 days of regrowth) log colony-forming units (cfu)/g forage. Maximum populations of these microorganisms were recorded in the silages on the seventh day of fermentation (8.69 log cfu/g silage). Enterobacteria populations persisted until the 28 th day, with maximum values found as early as the first day of fermentation (7.89 log cfu/g silage). Levels of DM, NDF, ADF and ADIN increased linearly whereas values of CP decreased linearly with age of regrowth of the plants. There was a linear reduction in the levels of DM, CP and NDF and linear increase in the levels of ADIN over the period of fermentation. N-NH 3 level decreased and increased linearly with regrowth age and fermentation period, respectively. The pH decreased exponentially with fermentation period. Lactic acid increased and butyric acid decreased linearly with regrowth age. The predominant Lactobacillus plantarum species in signalgrass plants is Lactobacillus plantarum.Key Words: acetic acid, butyric acid, enterobacteria, lactic acid, lactic acid bacteria Populações microbianas, perfil fermentativo e composição bromatológica de silagens de capim-braquiária em diferentes idades de rebrotação RESUMO -Foram avaliadas as populações microbianas, o pH, a relação nitrogênio amoniacal/nitrogênio total (N-NH 3 ), as concentrações de ácidos láctico, acético e butírico e a composição bromatológica de silagens de Brachiaria decumbens cv. Basiliski de cinco idades de rebrotação (30, 40, 50, 60 e 70 dias) utilizando-se silos laboratoriais de 2 kg de capacidade. Utilizou-se um esquema fatorial 5 × 6 (5 idades de rebrotação × 6 períodos de fermentação), em um delineamento inteiramente casualizado, com três repetições. Os períodos de fermentação foram 1, 3, 7, 14, 28 e 56 dias. Na forragem fresca, foram registradas populações de bactérias do ácido láctico variando entre 3,93 (30 dias de rebrotação) e 5,51 (70 dias de rebrotação) log unidades formadoras de colônia (ufc)/g de forragem. Nas silagens, foram registradas populações máximas desses microrganismos no sétimo dia de fermentação (8,69 log ufc/g de silagem). As populações de enterobactérias persistiram até o 28 o dia, com os valores máximos observados logo no primeiro dia de fermentação (7,89 log ufc/g de silagem).

Fermentation profile and microbial population were assessed in soybean silages without any additive (control), with inoculant (I), with I + powdered molasses (I+M), and with powdered molasses only (M). Soybean plants were harvested at the R6 stage and ensiled in 2kg-capacity laboratory silos. The additives were added to the natural matter base of silages. The assessed fermentation periods were 1, 3, 7, 14, 28, and 56 days. A 4 × 6 factorial arrangement (4 additives × 6 fermentation periods) in a completely randomized design with 3 replicates was used. Lactic, acetic, and butyric acids concentrations were influenced by additives and periods (P< 0.05). It was observed higher lactic acid values to control silages, on the 56th day. Lower average values of acetic and butyric acids were observed to I+M and M silages. It was observed quadratic effect to pH values with a reduction estimated of 0.5504, 0.5358, 0.6312 and 0.6680 units to pH values to control, I, I+M, and M silages in the first 10 days. A maximum lactic acid bacteria population was observed at the 28th day of fermentation in silages with inoculant. The inoculant and powdered molasses improve the fermentation profile of soybean silages.

Avaliaram-se os efeitos da fermentaçãode estirpes de Streptococcus bovis (HC5 e JB1) ede períodos de fermentação (dias após ensilagem)sobre o pH, a produção de amônia e o desenvolvimentode bactérias lácticas (BAL) e enterobactérias(ENT) em silagens de Panicum maximum cv.Mombaça. O delineamento experimental foi o inteiramentecasualizado, arranjado em um esquemafatorial 3 x 5 (controle e dois inoculantes e cincoperíodos de fermentação), com três repetições. Osvalores de NH3 aumentaram ao longo do período defermentação, enquanto pH diminuiu para todos ostratamentos, sendo que no último período de aberturaas concentrações de NH3 foram 10,69, 9,54 e8,93 mg/dl, e os valores de o pH foram 4,46, 4,27 e4,28, para os tratamentos controle, inoculado comHC5 e inoculado com JB1, respectivamente. O valormáximo de BAL na ausência de inoculante foiobservado no sétimo dia de fermentação (8,85 logUFC/g). As silagens inoculadas apresentaram valoresmáximos de BAL no décimo quarto dia, comvalores de 9,11 e 9,41 log UFC/g, para HC5 e JB1,respectivamente. Os valores de ENT, aos 28 diasde fermentação, foram 4,29, 3,60 e 3,57 log UFC/gpara as silagens controle, e inoculadas com HC5 eJB1, respectivamente. A inoculação aumentou, ainda,os teores de matéria seca e de proteína brutadas silagens, ao final do período de fermentação.A inoculação com Streptococcus bovis HC5 e JB1reduz o pH e diminui a concentração de amônia,além de favorecer o desenvolvimento de bactériaslácticas, em detrimento das enterobactérias, melhorandoo valor nutricional de silagens de capimmombaça.

Chemical composition was assessed in soybean silages without any additive (control), with a microbial inoculant (I), with I + molasses (I+M), and with molasses only (M). Soybean plants were harvested at the reproductive 6 (R6) stage and ensiled in 2 kg-capacity PVC laboratory silos. The SIL ALL C4 inoculant produced by Alltech Brazil was used in combination with or without 2.5% molasses added to the natural matter base. A 4 × 6 factorial arrangement (4 additives × 6 fermentation periods) in a completely randomised design with 3 replications was used. The assessed fermentation periods were 1, 3, 7, 14, 28, and 56 days. Excluding the dry matter and crude protein contents it was observed an interaction effect (P<0.05) between the additive and fermentation periods in the silages. It was observed higher average values of dry matter, equal 290.02 g kg-1, and crude protein, equal 151.28 g kg-1, to I+M and M silages, respectively. It was observed lowest values (P<0.05) to neutral detergent insoluble nitrogen (NDIN) and acid detergent insoluble nitrogen (ADIN) contents in I+M silages, equal 180.47 and 125.07 g kg-1, respectively. The addition of inoculant associated or not with molasses improved affect the chemical composition of soybean silages.