Silagens de capim-BRS capiaçu em diferentes idades de cortes e aditivos

Abstract

The BRS Capiaçu grass is known for its high mass production per unit area and is suitable for silage production. However, ensiling this grass is still a challenge due to its low dry matter content (DM; less than 200 g kg-1 DM) at the time of cutting. Therefore, the use of strategies to increase DM content and reduce losses during fermentation is essential for feeding ruminants. Based on the above, the aim of this study was to evaluate the chemical-bromatological composition, fermentation characteristics and digestibility of BRS Capiaçu grass silage at different cutting ages without and with additives. The experiment was conducted in two parts, the first at EPAMIG Norte, in the Experimental Field in Montes Claros, Minas Gerais, and the other at the Food Analysis and Animal Nutrition Laboratory at Unimontes - Janauba Campus. Three regrowth ages (90, 105 and 120 days) of BRS-Capiaçu grass for silage were evaluated. At each age, the grass was ensiled without additives (Treatment 1); application of microbial-enzymatic inoculant (Treatment 2); inclusion of 10% crushed corn (1-2 mm; Treatment 2) and association of 10% crushed corn (1-2 mm) with microbial-enzymatic inoculant. A completely randomized design was used in 3 x 4 subdivided plots with five replicates. The dose of inoculant used followed the manufacturer's recommendation. For N-NH3, there was no difference between the ages of regrowth, with an average of 8.58% of total nitrogen. The use of inoculants reduced effluent losses by 23.68% (P<0.01) compared to the control silage. There was a linear reduction in effluent losses as the grass-BRS Capiaçu-grew older. In addition, the dry matter (DM) content of the silage increased significantly (P=0.02) as the age of regrowth increased. The inclusion of 10% ground corn resulted in a 20.40% increase in DM content compared to control silage and silage with inoculant (average of 23.17%). SRS Capiaçu grass silages with ground corn and those associated with ground corn and inoculant had higher dry matter digestibility and lower indigestible neutral detergent fiber levels compared to the other treatments. It is recommended to harvest BRS Capiaçu grass after 120 days of regrowth for silage production. SRS Capiaçu grass silage with a 10% inclusion of ground corn associated with bacterial-enzymatic inoculant reduces losses during fermentation, improves the fermentation profile, chemical composition and digestibility of the silage.