Dynamic and nutritive value of forage systems submitted to the conventional and organic production

AbstractThe objective of this research was to evaluate the nutritive value on elephant grass pastures in two production systems. In the conventional system elephant grass was planted in rows 1.2 m apart from each other. In the organic system elephant grass was planted in rows 3 m apart from each other. In the space between alleys, in cool season, annual ryegrass was seeding; allowing the development of spontaneous growing species in the warm season. It was applied 100kg of N/ha with chemical and organic fertilizers (manure of cattle and pig slurry) in the respective pastures. Holstein cows receiving 0.9% of body weight complementary concentrate feed were used. Hand-plucked samples were collected to analyze chemical composition (mineral matter, organic matter, crude protein and neutral detergent fiber) and digestibility. The experimental design was completely randomized, with two treatments (systems) three replications (paddocks) with repeated measures (seasons). Eight and seven grazing cycles were performed during the experimental period for respective systems. Similar value was found in the chemical composition and digestibility of elephant grass in both pasture systems. The organic as much as conventional pasture systems showed high nutritive value considering the fertilization, management and utilization time.

摘要：本研究旨在评估两种生产体系下象草牧场的营养价值。常规生产体系中，象草以行距1.2米的规格种植；有机生产体系中，象草行距为3米。在条带间隙处，凉季播种一年生黑麦草，暖季则任由自然萌发的物种自然生长。两个体系的牧场分别施用100kg/ha的氮素，配合化肥与有机肥（牛粪及猪粪液）。试验选用荷斯坦奶牛，饲喂占其体重0.9%的补充精料。采用手采法采集样本，分析其化学成分（矿物质、有机质、粗蛋白与中性洗涤纤维）及消化率。试验设计为完全随机设计，设置2个处理（生产体系）、3次重复（放牧小区），并采用重复测量方案（按季节分组）。试验期内，两个体系分别完成8次和7次放牧循环。结果显示，两种牧场体系下象草的化学成分与消化率无显著差异。综合施肥方式、管理措施及利用时长来看，有机与常规牧场体系均具备较高的营养价值。