ABSTRACTThe objective of this study was to evaluate the production practices and use of corn silage in dairy farms in Southern Brazil, and to evaluate their impact on the nutritional quality and occurrence of mycotoxins. The data were collected by application of questionnaires among the producers, and by analysis of silage samples. The variables were subjected to factorial analysis of data reduction through the principal components method, thus obtaining 84.12% of the variance associated with the location, corn hybrid, crop production management, and inoculant used, characterizing the farms into four distinct groups. In farms from Paraná, the silage production technologies were more associated with implantation and crop management processes, and investment in equipment related to ensilage/silo feed-out was less frequent. Farms of Rio Grande do Sul showed high adoption of outsourced services, self-propelled machines, bunker silos, double-sided plastic film, and inoculant to control aerobic deterioration, and the silages showed higher levels of propionic acid (7.95 g/kg DM), and lower concentrations of aflatoxins (7.7 ppb) and total mycotoxins (26.58 ppb). The farms evaluated in Southern Brazil have good production efficiency and corn silages with excellent quality, regardless of their production characteristics.

Objetivou-se avaliar o potencial de utilização do estilosantes campo grande na forma de silagem, através do valor nutritivo de silagens a vácuo, submetidas a diferentes tempos de abertura e uso de aditivos. Utilizou-se um delineamento inteiramente casualizado em esquema fatorial 4 x 4, sendo quatro tratamentos: sem inoculante; com inoculante; com inoculante mais uréia e apenas com uréia, com quatro tempo de abertura (14, 28, 42 e 56 dias) e quatro repetições. Observou-se que as silagens sem inoculante apresentaram menores valores de pH e de temperatura, em relação aos demais tratamentos. Todas as silagens apresentaram maiores índices de recuperação da matéria seca no primeiro tempo de abertura, diminuindo posteriormente. As silagens de estilosantes apresentaram altas concentrações de proteína bruta, em média 167,30g/kg de MS, sendo os maiores valores encontrados nas silagens com adição de uréia. As silagens sem o uso de aditivo apresentaram melhor composição químico-bromatológica, em relação aos demais tratamentos com aditivos, sendo observados valores médios de 539,17g/kg e 665,79g/kg de MS, para as concentrações de nutrientes digestíveis totais e digestibilidade "in vitro" da matéria seca, respectivamente. O estilosantes campo grande apresenta potencial para ser utilizado na forma de silagem.

The aim of this study was to evaluate the potential use of Stylosanthes spp. cv. Campo Grande in silage form, through of the nutritive value of vacuum packed silages, under different opening times and use of additives. It was used a completely randomized design in factorial scheme 4 x 4, with four treatments: no inoculant; with inoculant; with inoculant plus urea and urea only, with four opening time (14, 28, 42 and 56 days) and four replications. It was observed that the silages no inoculant had lower values of pH and temperature, compared to other treatments. All silages had higher dry matter recovery in the first time of the opening, decreasing thereafter. The stylosanthes silages showed high concentrations of crude protein, on average 167.30 g/kg DM, with the largest values found in silage with urea addition. The silage without additive showed better chemical composition, compared to other treatments with additives, being observed mean values of 539.17 and 665.79 g/kg DM for concentrations of total digestible nutrients and "in vitro" dry matter digestibility, respectively. The campo grande stylosanthes presents potential to be used in the form of silage.