Chemical composition of maize silages with different packing densities

[摘要] The experiment in a complete randomized design aimed to test the effect of two packing densities, 500 kg (medium) and 600 kg (high) of silage mass per cubic meter, on silage quality as compared to the original fresh material. Silages were prepared on May 18th, 2004 from a late season harvest of a maize crop at the half milky half dough kernel stage. Chopped materials with 1.2 cm theoretical particle size were packed manually in 30 liters mini-silos, in four replicates for each packing density, immediately after harvest. The different packing densities affected significantly the concentration of soluble sugars (1.60 vs. 2.15% of DM), 80% ethanol insoluble organic matter (76.02 vs. 71.53% of DM), non-structural carbohydrates (39.21 vs. 41.70% of total carbohydrates), neutral detergent fiber corrected for ash and protein (52.57 vs. 50.37% of DM), acid detergent lignin (2.74 vs. 2.57% of DM), and ammonia-nitrogen (4.35 vs. 3.84% of total nitrogen), respectively, for the "medium" and "high" packing densities. A higher ensiling packing density improved the conservation of soluble sugars, altered less the structural carbohydrates and reduced proteolysis in maize silage.

[学科分类] 兽医学

[关键词] carbohydrate;maturity stage;NDF;protein;starch;TDN     IntroduçãoO grande desafio na alimentação de ruminantes de alta produtividade é aumentar sua capacidade de ingestão de alimento para suprir suas necessidades nutricionais sem prejudicar os processos fisiológicos no rúmen;ou seja;mantendo a atividade de ruminação com consumo adequado de volumoso