de Oliveira G.C.,Scholar from CAPES |
Moreira I.,Av. Colombo |
Furlan A.C.,Av. Colombo
Revista Brasileira de Zootecnia | Year: 2011
Two experiments were carried out to determine the nutritional value and verify piglets' performance in the nursery phase fed with diets containing common corn (CC), extruded common corn (ECC), high-lysine corn (HLC), extruded high-lysine corn (EHLC), high-oil corn (HOC) and extruded high-oil corn (EHOC). In the total digestibility trial 14 barrows averaging 6.49 ± 0.16 kg initial body weight were allotted in metabolism cages, distributed in a randomized design with seven diets, six replicates, and one piglet per experimental unit. The values of digestible energy (DE), as well as metabolizable energy (ME) as-fed basis for CC, ECC, HLC, EHLC, HOC and EHOC were: 3,428 and 3,327 kcal/kg; 3,439 and 3,355 kcal/kg; 3,533 and 3,414 kcal/kg; 3,515 and 3,427 kcal/kg; 3,483 and 3,377 kcal/kg; 3,585 and 3,482 kcal/kg, respectively. In the performance experiment, 84 piglets, weaned at 21 days old, initial live weight of 6.06 ± 0.54 kg were used. Animals were allotted in a completely randomized design in a 3 × 2 factorial arrangement, using three types of corn (CC, HLC and HOC), two forms of processing (processed or not by extrusion), seven replicates and two piglets per experimental unit. Six diets containing CC, ECC, HLC, EHLC, HOC and EHOC were studied. There were no advantages in the digestibility and performance by extruding the types of corn with different nutritional profiles, for their use in commercial diets for piglets. The results of the two experiments emphasize the importance of segregating the types of corn, extruded or not, in their real chemical and energetic composition as well as the values of true digestible amino acids for the formulation of piglet diets in the nursery phase. © 2011 Sociedade Brasileira de Zootecnia.
Nanni M.R.,Av. Colombo |
Povh F.P.,University of Sao Paulo |
Dematte J.A.M.,University of Sao Paulo |
de Oliveira R.B.,Av. Colombo |
And 2 more authors.
Scientia Agricola | Year: 2011
The importance of understanding spatial variability of soils is connected to crop management planning. This understanding makes it possible to treat soil not as a uniform, but a variable entity, and it enables site-specific management to increase production efficiency, which is the target of precision agriculture. Questions remain as the optimum soil sampling interval needed to make site-specific fertilizer recommendations in Brazil. The objectives of this study were: i) to evaluate the spatial variability of the main attributes that influence fertilization recommendations, using georeferenced soil samples arranged in grid patterns of different resolutions; ii) to compare the spatial maps generated with those obtained with the standard sampling of 1 sample ha -1, in order to verify the appropriateness of the spatial resolution. The attributes evaluated were phosphorus (P), potassium (K), organic matter (OM), base saturation (V%) and clay. Soil samples were collected in a 100 × 100 m georeferenced grid. Thinning was performed in order to create a grid with one sample every 2.07, 2.88, 3.75 and 7.20 ha. Geostatistical techniques, such as semivariogram and interpolation using kriging, were used to analyze the attributes at the different grid resolutions. This analysis was performed with the Vesper software package. The maps created by this method were compared using the kappa statistics. Additionally, correlation graphs were drawn by plotting the observed values against the estimated values using cross-validation. P, K and V%, a finer sampling resolution than the one using 1 sample ha -1 is required, while for OM and clay coarser resolutions of one sample every two and three hectares, respectively, may be acceptable.