Felipe Nogueira Domingues

Estabilidade aeróbia, pH e dinâmica de desenvolvimento de microrganismos da cana-de-açúcar in natura hidrolisada com cal virgem

Objetivou-se com este trabalho avaliar o efeito da adicao de cal virgem e dos tempos apos a aplicacao sobre a estabilidade aerobia e o crescimento de microrganismos (leveduras e fungos) na cana-de-acucar in natura. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro repeticoes. Avaliaram-se a estabilidade aerobia (temperatura), a dinâmica de desenvolvimento de leveduras e fungos e o pH, em um esquema de parcelas subdivididas, com cinco doses de cal (0; 0,5; 1,0; 1,5 e 2,0%) e cinco tempos apos aplicacao (0, 24, 48, 72, 96 horas). Houve efeito significativo das doses de cal para todos os parâmetros avaliados. A cana que nao foi tratada com cal (0%) apresentou quebra da estabilidade no menor intervalo de tempo. Os valores de pH aumentaram gradativamente de acordo com a dose de cal aplicada e diminuiram com o tempo apos aplicacao. Houve aumento numerico na contagem de leveduras ate as 72 horas apos a aplicacao da cal, independentemente da dose, e os valores tenderam a estabilizar no tempo de 96 horas pos-tratamento. Nao houve efeito significativo das doses de cal sobre o desenvolvimento dos fungos. A aplicacao de cal virgem e eficaz no controle do crescimento de leveduras e aumenta a estabilidade aerobia da cana-de-acucar in natura.

Ruminal degradability of tropical leguminous plants from eastern Amazonia

The aim of this study was to evaluate ruminal degradation of dry matter (DM), crude protein (CP), and neutral detergent fiber (NDF) of Cratylia argentea, Flemingia macrophylla (Willd.) Merrill, and Stylosanthes guianensis ‘Campo Grande’ (EMBRAPA), aged 55 and 75 days, in sheep with rumen cannulas, using the in-situ technique. A factorial design of 3 leguminous plants × 2 ages × 6 incubation times was used, totaling 36 experimental units. The experimental period included 14 days for adaptation to diet and 5 days for data collection. Cratylia at both ages and Flemingia aged 55 days showed the highest “a” fraction values for DM degradability. Cratylia aged 55 days and Stylosanthes at both ages showed the highest “a” fraction values for CP. The highest “b” fraction value for DM was 51.27% for Stylosanthes aged 55 days. This rate was lower for the other leguminous plants, especially for Flemingia at both ages. The “b” fraction values for NDF are considered low for Flemingia, what may be the result of lower ruminal degradation. The highest “c” fraction degradation rate for DM was observed in all leguminous plants studied aged 75 days. The highest “c” fraction value for CP was 14.84% for Stylosanthes aged 75 days. The highest Kd fraction values for DM, NDF, and CP were found in Flemingia. Cratylia, and Stylosanthes aged 75 days presented higher effective degradability (ED) values for DM at 2 and 5%/hour compared to Flemingia at both ages. Cratylia and Stylosanthes had the highest ED values for NDF, regardless of their passage rates. Stylosanthes presented higher ED values for CP at both ages, regardless of its passage rate. The highest DM, NDF, and CP potential degradability (PD) was obtained for Cratylia and Stylosanthes, at both ages. The leguminous plants Cratylia and Stylosanthes can be recommended for use as a protein bank and supplementation for ruminants, whereas, Flemingia macrophylla should not be used as a protein supplement for ruminants, because it contains high levels of fibrous fractions.

Production and chemical composition of three sugarcane cultivars grown under Af climate conditions

The objective of this study was to evaluate the chemical composition and yield of three sugarcane cultivars grown under Af climate conditions. Three sugarcane cultivars were examined, namely, IACSP93-6006, RB83-5486, and SP79-1011, in a randomized block design with three treatments, four blocks, and two replicates per block; means were compared using Tukeys test at 5% probability level. Significant differences were observed for dry matter, ether extract, crude protein, acid detergent fiber, lignin (LIG), cellulose, neutral detergent fiber corrected for ash and protein (NDFap), total carbohydrates, carbohydrate fractions B2 and C, and dry matter yield. The fiber components (NDFap, LIG, and fraction C) displayed low values. The cultivars produced high dry matter yields, especially IACSP93-6006 and SP79-1011. There were no differences among sucrose (Pol) values and the NDF/Pol ratios. The low Pol values indicate that sugarcane grown under Af climate conditions does not produce high levels of sucrose. The three sugarcane cultivars grown under the Af climate conditions produce high yields of DM/ha but low concentrations of the fiber components, as well as low Pol concentrations.

Palm kernel meal as additive in the elephant-grass silage

The objective of this study was to evaluate the effect of adding palm kernel meal (BP) as an additive in elephant grass silage. The chemical qualitative and fermentation were analysed in a completely randomized design with six treatments, one with no BP (C) and six replications, where the averages of the results of days of closing and opening were analysed by regression analysis. We collected samples at the time of ensiling and after 190 days of storage for evaluation of dry matter, crude protein, carbohydrates (total, non-fibrous, water-soluble, cellulose and hemicellulose), ash, lignin and ether extract. In aerobic phase, we collected samples for pH, ammoniacal nitrogen, fungi and yeasts. The elephant grass of this experiment showed values of 13.9% DM and 8.25% CP while the BP has 77.2% DM and 16.9% CP. The inclusion of BP had inhibited the growth of fungi and yeasts. The increase in the content of BP decreased the concentration of NH3-N. Higher concentrations of BP in silage were more stable, and the stability breaks in 72 hours, while the stability of C was 19 hours. Concentrations above 15% BP had no significant variations in pH in the aerobic phase. The inclusion of palm kernel meal at concentrations 10% to 15% can be used in silage of elephant grass, inhibiting undesired fermentation and making them more stable. Concentrations above this value may affect the nutritive value of silage by high lignin content of the additive.

Hydrolysis of sugarcane with lime or hydrated lime.

The objective of the present work was to evaluate the effect of the alkaline treatment of sugarcane with virgin lime or hydrated lime on the bromatologic composition and in vitro digestibility of dry matter, neutral detergent fiber, and acid detergent fiber. It was used a complete random design with a 3 × 3 factorial scheme composed by three forms of of sugarcane processing (in natura sugarcane; hydrolyzed sugarcane with 0.5% virgin lime; and hydrolyzed sugarcane with 0.5% hydrated lime) and three storage times (12, 36 and 60 hours). The forms of processing changed the contents of organic matter, mineral matter, total carbohydrates, and hemicellulose as well as the contents of neutral detergent fiber and total digestible nutrients. Times of storage changed contents of crude protein, organic matter, total carbohydrates and hemicellulose. Among the minerals, only content of calcium showed an increase for the sugarcane processing forms. Coeficients of digestibility of dry matter and neutral detergent fiber increased with hydrolises of sugar cane when compared to in natura sugarcane. Hydrolisis with hydrated lime or with virgin lime keeps the nutrional value of sugarcane making its use possible up to 60 hours after storage.