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Magalhaes F.A.,Federal University of Vicosa | Valadares Filho S.C.,Federal University of Vicosa | Menezes G.C.C.,Federal University of Vicosa | Machado M.G.,Federal University of Vicosa | And 4 more authors.
Revista Brasileira de Zootecnia | Year: 2012

The objective of this study was to evaluate the effect of sugar cane ensilage with different Brix degrees, with or without the addition of 0.5% of calcium oxide (lime) on the chemical composition and fermentation losses of silages. A complete random design in a 9 × 2 factorial arrangement was used. Experimental silos were used, ensilage was done every 15 days with Brix measuring, and they were opened after 30 days of fermentation. As the Brix degree of the ensiled material increased, the contents of dry matter (DM) increased and contents of ash, crude protein (CP) and fibers (neutral and acid detergent fiber corrected for proteins - NDFap and ADFap) reduced. After fermentation, DM content of the silage presented a linear increase with the Brix degree content concentration, positively correlating with content of lime, but the contents of ash, CP, EE and NDFap were linearly reduced with the Brix increase. Content of ADFap suffered linear reduction for the treated silage whereas quadratic behavior was found in the untreated silage. Production of ethanol was presented in a quadratic manner for the silages without lime, and cubically in silages with lime, according to the Brix degree. The treated or untreated silages presented an average pH of 3.98 and 3.50, respectively. Contents of acetic acid and butyric acid were not affected by the lime content and Brix degree. Untreated silages presented reduction of contents of propionic acid as the Brix degree increased. The higher the Brix degree value, the higher the total losses of dry matter in the sugar cane silages with or without treatment. The treatment of the sugar cane with 0.5% calcium oxide on the natural matter basis is effective in reducing the undesired fermentation of the ensilage material. © 2012 Sociedade Brasileira de Zootecnia. Source

Souza A.P.,Institute Ciencias Agrarias e Ambientais | Escobedo J.F.,Sao Paulo State University | Pai A.D.,Av. Jose Italo Bacchi s n | Gomes E.N.,Sao Paulo State University
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2011

Statistics equations and validations with groups of annual and monthly data were evaluated for global, direct and diffuse solar radiation components incident on the tilted surface to 12.85, 22.85 and 32.85° with the face North, in climate and geographical conditions of Botucatu, SP. It was employed the fractions of three components of extraterrestrial radiation in correlation with the coefficient clearness index horizontal plane, in a database of April/1998 to December/2007, whose measures at different periods in three inclinations, however concomitant to the horizontal plane. Increasing the angle of the surface led to increased scattering of the daily values of clearness index for inclined and horizontal surfaces. In annual groups, the lower performances were observed in the estimation of inclined daily diffuse radiation, with maximum Root Mean Square Error to 3.89 MJ m -2 d -1 (43.65%) and adjustments around 62%. In estimates of global and direct components of solar radiation on inclined planes, both annual and monthly equtions can be applied, with performance dependents to climatic conditions. Source

de Carvalho D.F.,Vegetal | da Silva D.G.,Institute Ciencias Agrarias e Ambientais | de Souza A.P.,FRRJ | Gomes D.P.,Federal Rural University of Rio de Janeiro | da Rocha H.S.,Federal Rural University of Rio de Janeiro
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2011

The reference evapotranspiration (ETo) is dependent on the amount of energy available in the environment, being solar radiation (SR) as an important variable in its estimation. This study was carried out in order to determine the coefficients "a" and "b" of the Angstron-Prescott equation for Seropédica, Rio de Janeiro State, Brazil, and to evaluate their effects on the SR and ETo estimation. Measures of global solar radiation and effective number of hours of sunshine were used from station Ecology Fund (83741 - INMET) for the period of 2000 to 2007. The coefficients were determined by linear regression analysis for the entire period and monthly and yearly periods. Using the calculated coefficients and those proposed by FAO (0.25 and 0.50) SR and ETo were estimated and evaluated their performance. The average monthly coefficients "a" ranged from 0.232 to 0.299 and "b" from 0.397 to 0.504. Annual mean coefficients "a" and "b" were 0.295 and 0.417, and for general period were 0.282 and 0.433, respectively. The best performance observed for the estimated SR and ETo was obtained when the monthly coefficients of the equation Angströn-Prescott were adopted. Source

Neto M.C.,SEBRAE | Campos J.M.S.,University of Pernambuco | de Oliveira A.S.,Institute Ciencias Agrarias e Ambientais | Gomes S.T.,Vicosa MG
Revista Brasileira de Zootecnia | Year: 2012

The objective of this study was to identify and quantify benchmarks of milk production systems. The technological profile and size, livestock and economic indicators of sixteen farms in the region of Triângulo Mineiro were analyzed. Indicators correlated with rate of return on capital (RRC) were identified and quantified in four scenarios of RRC (6, 8, 10 and 12% per year). The correlated indicators and their respective values in the four scenarios were: land (99, 90, 81 and 73 ha); relation of total cows in lactation (74, 77, 79 and 82%); lactating cows per area (0.89; 0.99; 1.11 and 1.22 cows/ha); milk production per lactating cow (12.04; 13.00; 13.96 and 14.92 liters/cow/day); milk production per total cows (9.19; 10.23; 11.27 and 12.31 liters/cow/day); labor productivity (322, 349, 375 and 402 liters/day/man); land productivity (4351, 5236, 6120 and 7004 liters/ha/year); participation of total effective operational cost of activity in the gross revenue of the activity (69, 66, 63 and 60%); participation of total operational cost of activity in the gross revenue of the activity (80, 76, 72 and 69%); participation of total cost of activity in the gross revenue of the activity (93, 88, 82 and 77%); labor cost in relation to milk gross revenue (15, 13, 11 and 9%); profitability (15, 19, 23 and 28%); and capital investment in the activity in relation to daily milk production (922, 829, 736 and 644 R$/liter-day). The productivity of the factors land and animals present more correlation with profitability than labor productivity, regardless of the production size. ©2012 Sociedade Brasileira de Zootecnia. Source

Magalhaes F.A.,Federal University of Vicosa | Filho S.D.C.V.,Federal University of Vicosa | Menezes G.C.D.C.,Federal University of Vicosa | Gionbelli M.P.,Federal University of Vicosa | And 4 more authors.
Revista Brasileira de Zootecnia | Year: 2012

The objective of this study was to evaluate low and high Brix diets, treated or not with 5 g of calcium oxide per kg of natural matter, and corn silage on intake, digestibility and performance of beef cattle. Forty cattle with initial body weight (BW) of 350 kg were used: five composed the control group, 30 were distributed into random blocks (control) and the other five were distributed in a 5 × 5 incomplete Latin square, with the objective of determining digestibility. The 30 animals evaluated for performance were slaughtered and empty body weight (EPW), carcass dressing and meat cuts were determined. The diet with corn silage (CS) presented the best intake of the other ingredients and the best weight gain, except for neutral detergent fiber intake in g/kg of BW. Only carcass dressing, in relation to BW and EBW, was not affected by the treatments, and the others were greater for animals fed diets with sugar cane silage. Animals fed diets with high brix sugar cane silage and treated high brix sugar cane silage presented lower intake of indigestible neutral detergent fiber and neutral detergent fiber corrected for ash and protein (g/kg of BW) in relation to diets with low and high brix sugar cane silage, respectively. Animals fed diets with corn silage presented higher digestibility, except for crude protein and non-fibrous carbohydrates. Animals subjected to diets with corn silage presented low excretion of nitrogen compounds and higher microbial crude protein synthesis. Animals fed sugar cane silage present greater intake, performance and digestibility. The use of lime during 15 or 20° Brix sugar cane ensilage does not alter intake, digestibility or performance of beef cattle. © 2012 Sociedade Brasileira de Zootecnia. Source

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