No abstract

No abstract

An experiment was conducted to evaluate the effect of three application rates (0,1 and 2 times the recommended rate) of a commercial additive containing a lactic acid-producing bacterial inoculant as well as plant cell walldegrading enzymes, on the microbial succession, fermentation end-products, and aerobic stability of guinea grass (Panicum maximum var. Jacq.) silage. Vegetative material was harvested at 30% dry matter (DM) and chopped into 2.5-cm pieces. At ensiling, three treatments were imposed: no additive (control), additive applied at recommended rate, and at 2x the recommended rate. Three silos per treatment were opened after 0, 2, 4, 7, 14, 28, and 56 d of fermentation, and siiage was analyzed for pH, microbial succession, chemical composition, fermentation end-products and aerobic stability. For aerobic stability determination, three silos per treatment were opened at the end of the fermentation period, and silage (400 g) was exposed to air for three days in Styrofoam containers lined with plastic. After 0 , 1 , and 3 d of aerobic exposure, silage was analyzed for pH, microbial populations (total bacteria, yeast and molds), water soluble carbohydrate content, fermentation end-products and in vitro dry matter degradability (IVDMD). Temperature was monitored daily and dry matter recovery (DMR) was calculated after 1 and 3 d of aerobic exposure. The addition of the commercial additive, applied one or two times the recommended rate, increased (P < 0.05) the lactic acid producing bacterial population and decreased (P < 0.05) conforms during early stages of the fermentation process, but did not influence the yeast and mold populations or the chemical composition of the resulting silage. Use of the inoculant-enzyme mixture also resulted in siiage with higher lactic acid content 56 days post ensiling. The silage additive did not inffuence pH, temperature, microbial populations, soluble carbohydrate content, IVDMD or DMR of guinea grass silage after exposure to air. In summary, use of the commercial additive applied at the recommended rate partially improved the fermentation characteristics of guinea grass silage, but did not enhance its aerobic stability. Increasing the application rate to twice the recommended rate did not result in better fermentation.

An experiment was conducted to determine the effects of including legume species (Leucaena leucocephala, Stylosanthes guianensis, Centrosema pubescens Benth or Neonotonia wightii) at levels of 0, 5, 10, 20, and 40% of the dry matter on the chemical composition (crude protein, CP neutral detergent fiber, NDF; acid detergent fiber, ADF) and on in vitro dry matter digestibility (IVDMD) of mixtures of each legume with four grass species (Cynodon nlemfuensis Vanderyst, Panicum maximum jacq., Pennisetum purpureum Schum., or Sorghum bicolor (L.) Moench). Of the legume species included, Leucaena leucocephala and Centrosema pubescens had the highest CP content and IVDMD, respectively. For the legumes, the mean CP and IVDMD values, respectively, were Leucaena leucocephala, 21.98 and 68.09; Stylosanthes guianensis, 13.70 and 63.44; Centrosema pubescens, 18.29 and 68.60; and Neonotonia wightii, 16.72 and 66.64%. For the grasses, they were, respectively, Cynodon nlemfuensis, 8.27 and 61.38; Panicum maximum, 7.64 and 60.06; Pennisetum purpureum, 8.02 and 53.47; and Sorghum bicolor, 7.57 and 59.62%. Neutral detergent fiber and ADF contents were higher in the grasses (Cynodon nlemfuensis, 73.03 and 44.45; Panicum maximum, 65.27 and 49.06; Pennisetum purpureum, 69.26 and 51.88; and Sorghum bicolor, 60.24 and 50.99%, respectively) than in the fegumes (Leucaena leucocephala, 50.52 and 28.50; Stylosanthes guianensis, 52.57 and 36.63; Centrosema pubescens, 58.43 and 34.84; and Neonotonia wightii, 54.11 and 33.23%, respectively). The chemical composition of the forages varied according to the relative proportions of the species included, as expected. However, the effects on IVDMD were not additive; rather, associative effects, mainly antagonistic, were observed in most of the mixtures.

SUPLEMENTACION DE SELENIO A VACAS LECHERAS POR MEDIO DE BOLO RUMINAL O INYECTABLE

CELL WALL DISAPPEARANCE IN A FORAGE SORGHUM HYBRID AND JOHNSON GRASS AFTER TREATMENT WITH A COMMERCIAL MULTI-ENZYME PREPARATION

No abstract

An experiment was conducted to evaluate the effectiveness of a commercial lactic acid-producing bacteria! inoculant (LAPBI) applied at 0, 1, and 2 times the recommended rate to improve the fermentation characteristics and aerobic stability of grain sorghum (Sorghum bicolor var Jupiter) ensiled in a tropical environment.The sorghum was harvested at 90 d of growth and chopped into 2.5-cm pieces. At ensiling, three treatments were imposed: no additive (control), and LAPBI applied at the recommended (5.477 cfu/g of fresh forage) or higher rate (5.788 cfu/g of fresh forage). Three silos per treatment were opened after 0, 2, 4, 7, 14, 28, and 56 d of fermentation, and silage was analyzed for pH, chemical composition and fermentation end-products. Addition of the LAPBI did not markedly influence the chemical composition of the silages at either rate. It did increase the acidity and acetic acid content during early stages of fermentation, and the lactic acid content at 56 d post-ensiling, but did not reduce the deterioration of silage after exposure to air. It is concluded that use of the LAPBI, applied at the recommended rate, partially improved the fermentation characteristics of the grain sorghum silage, but did not enhance its aerobic stability. Doubling the application did not produce beneficial effects.