Produção e composição bromatológica de três cultivares do gênero Brachiaria submetidos a quatro intervalos de corte

Abstract

The forage harvesting time, either by cutting or grazing, must be related to the stage of development of the plant, which consequently determines its nutritional value. The experiment at the Showcase of Agricultural Technologies of Embrapa Western Amazon, located in Parintins-AM. An area of 60 square meters was used for forage assessments. The objective of this work was to evaluate the production and bromatological composition of three cultivars of the genus Brachiaria (Mulato II, Mavuno and Ruziziensis) maintained at four cutting intervals. The experimental design used was completely randomized, with treatments distributed in a 3 x 4 factorial scheme. The treatments consisted of three forage plants (Mulato II HD364, Mavuno, and B. Ruziziensis) and four cutting ages (14, 21, 28, and 35 days). The data obtained were analyzed using the Statistical Analysis System software (SAS v. 8.6). The difference between treatment means was evaluated by Tukey's test at 5% probability. The highest dry mass production (2209 KgMS/ha) was observed in Mavuno grass after 28 days of cutting. It was verified that the Mulato II kept its production stable during the analyzed period, not differing between the cuts made. Ruziziensis fed the management height goal at 21 days, but with low DM production. The NDF values found for all forage evaluations were always above 65%, regardless of cutting age. Regarding the crude protein content, in all the cuts performed on Ruziziensis, CP values were slightly above 15%. For Mulato II and Mavuno grass, the behavior of the average CP content over time followed the same conformation for both cultivars; it is noted that there was a significant decrease in the CP content at different cutting intervals. In maintained conditions, we observed that in terms of productivity, the Mavuno grass showed greater height and production, in addition to presenting good composition. Brachiaria Ruziziensis had the highest CP content.