Efeitos da altura de corte na produção, valor nutricional e perdas fermentativas da silagem de milho (Zea mays)

Abstract

The objective of this work was to evaluate the effects of the cutting height of maize (Zea mays) plant for silage on productivity, nutritional value and fermentative losses of silage. The experiment was carried out from September 2021 to April 2022, in a completely randomized design, with treatments formed by different cutting heights of the corn plant for silage: close to the ground (0.0 cm from the ground); 30.0 cm above the ground (control); 70.0 cm above the ground and close to the ear (1.0 cm below the ear). The dry matter (DM) production of corn silage ranged from 18.52 to 30.18 t/ha, with a gradual decrease as the cutting height increased. The DM production of residue varied from 0.0 to 27.81 t/ha as the cutting height of the plant was changed. Larger amounts of residue DM remained in the area when the plant was cut close to the ear, with no material remaining when the cut was performed close to the ground. For the crude protein (CP) levels, a treatment effect was also observed (p<0.05), with the values increasing as the cutting height increased, with the exception of the cut at 30 cm height, which presented similar CP levels (p>0.05) to treatments with cutting height close to the ground and 70 cm high. In general parameters, the highest fermentative losses were observed in treatments closer to the ear, this is due to the higher concentration of soluble carbohydrates in the silage with cuts closer to the ear. Raising the cutting height of the plant improves the nutritional value of corn silage, but reduces the production of silage dry matter.