Valor nutritivo de silagens do híbrido de milho BRS 3042 colhido em quatro estádios de maturação

Abstract

The plant breeding companies make several corn genotypes available on the market each year for silage production. The maturation stage for ensilage of these corn genotypes must be evaluated, as it influences the DM content, proportion of the plant constituents, fermentation process, chemical composition and, consequently, the productivity and nutritional value of the silages. The BRS 3042 corn hybrid was ensiled at maturation stages with grains without milk line (24.56% DM), ¼ milk line (29.10% DM), ¾ milk line (38.78% DM) and full grain (45.74% DM). The objective was to determine the best maturation stage for ensilage of this corn hybrid. The highest effluent losses and total dry matter losses were in the forage ensiled at the maturation stage without milk line (47.84 kg/t NM and 5.50 kg/t DM, respectively). The pH was adequate in all silages. The N-NH3/NT increased with the advance of the maturation stage. Lactic acid predominated among organic acids and was higher in forage ensiled at the maturation stage without milk line (11.85% DM). The microorganism count increased after the loss of aerobic stability in all silages. The dry matter productivity (DMP) and digestible dry matter yield (DDMY) were similar at all maturation stages (17.0 and 11.02 t/ha, respectively). The levels of NDF and ADF of the silages reduced until the maturation stage of the milk line (8.51% and 15.23%, respectively). CP contents were not changed. The NFC and starch levels increased due to the increase of 18.06% in the proportion of spikes. However, the DM, CP and NDF intake reduced until the maturation stage ¾ milk line (25.50%, 48.27%, 39.34% DM, respectively). The DM, CP and NDF digestibility decreased (10.46%, 20.85% and 33.11%, respectively). The best maturation stage for silage of the BRS 3042 corn hybrid is without milk line.