Silagem de milho com e sem inoculante enzimo-bacteriano sobre desempenho, características de carcaça e qualidade de carne de bovinos mestiços terminados em confinamento

Abstract

This work was carried out to study two height cuts of corn silage with or without inoculants enzymes on performance and carcass characteristics of bulls crossbred (F1 - ½ Nelore vs ½ Angus) finished in feedlot for 68 days. It was used 32 bulls with 20 months and final average weight of 374 + 25 kg. The bulls were kept in individual pens (10 m2). The diets were 50% roughage and 50% concentrate and were calculated to have 1.80 kg/day of gain. The experimental design, with four diets and eight replications (animals), was completely randomized. The corn silage was harvest with different cutting heights: low cut (25 cm) and high cut (45 cm) with addition or not of enzyme inoculants. It was determined the final live weight, average daily gain, feed intake (dry matter, crude protein, organic matter and neutral detergent fiber), feed efficiency, carcass characteristics (weight, dressing, conformation, length, fat thickness, muscle area, marbling, texture, color and pH), the muscle, fat and bone percentages (11th and 12th ribs), chemical composition (moisture, ashes, crude protein, total lipids and total cholesterol), fatty acid profile and sum of saturated fatty acid, monounsaturated, polyunsaturated, fatty acid n-3, fatty acid n-6, ratio polyunsaturated: saturated and ratio n-6: n-3). The cutting height and the use or not of inoculants to corn did not affect (P>0.05) the final live weight, average daily gain, feed intake, alimentary efficiency, carcass characteristics, meat quality and fatty acid profile. In conclusion, for cattle finished in feedlot with 1.8 kg daily gain the high cutting of corn to silage (45 cm of soils) and the use or not of inoculants are not necessary.