Ana Carolina Cruvinel Guimarães Azevedo
Abstract:
The shortage of forage in winter is a barrier to livestock in Brazil, and even precarious production systems are forced to opt for tropical grass ensiling processes. However, tropical forages have low dry matter content, low soluble carbohydrate concentration and high buffer capacity, which allows undesirable fermentations within the silo. Considering the importance of controlling the production of fermentable substrates for silage quality and conservation, the aim of this study was to evaluate the bromatological composition of wilting grass and piatã silages and added additives. The experiment was conducted at the Fontes do Saber farm, University of Rio Verde, located in Rio Verde-GO. The experimental design was completely randomized, with four replications, in a 2 x 4 factorial scheme, and in the first phase, two cultivars (xaraés and piatã) were used and the wilting times (0, 2, 4 and 6 hours). In the second phase, the wilted silage under 4 hours of sun exposure was compared with the control (xaraés and piatã grass silage), silage inoculated with bacterial enzyme inoculant and silage with 15% millet addition. For the silage process the Xaraés and Piatã grasses were harvested at the 40-day growth stage, at 20 cm from the ground level. According to the results obtained, the wasting time of 4 hours was favorable to increase the MS, PB and NDT content, to reduce the fibrous fraction contents and to promote the pH lowering in the xaraés and piatã grass silages. In the additive silages treatments with inoculant and addition of 15% of millet bran were efficient in increasing the CP content (8.72% to 12.46%) and (10.07% to 12.95%); in providing the rapid decrease in pH values (5.00 to 4.00) and (4.95 to 4.00), as well as decreasing the fibrous fraction components of the xaraés and piatã grass silages, respectively.
