ABSTRACT

This study evaluated the effects of amylolytic enzymes on the nutritive value, fermentation losses, fermentation profile, and amylolytic activity of rehydrated corn that had been stored for 30, 60, 90, 120, 150, 180, 210, or 240 d. Corn kernels were harvested, ground in a knife mill using a 4-mm screen, rehydrated to 625 g/kg of dry matter (DM). These experimental silos were then randomly assigned to the following treatments (n = 40 each): 1) CON (control) – rehydrated corn silage with no exogenous enzymes incorporated during the ensiling process; 2) AMY – rehydrated corn silage with exogenous alpha-amylase incorporated at 90 U/kg of fresh matter; and 3) GLU – rehydrated corn silage with exogenous glucoamylase incorporated at 90 U/kg of fresh matter. It was found that enzyme incorporation decreased the DM, starch, and non-fibre carbohydrate and increased the total losses and contents of crude protein, ether extract. Enzyme incorporation also reduced the silage pH, while increasing the lactate concentration. silages in the GLU treatment had higher aerobic bacteria counts and acetate and propionate concentrations. Amylolytic enzymes increased fermentation losses and the lactate and ethanol contents and decreased the nutritive value of rehydrated corn silage, reducing the starch content and DM degradation.

摘要

本研究评估了淀粉分解酶对储存 30、60、90、120、150、180、210 或 240 天的复水玉米的营养价值、发酵损失、发酵曲线和淀粉分解活性的影响。收获玉米粒，在使用 4 毫米筛网的刀磨机中研磨，再水化至 625 克/千克干物质 (DM)。然后将这些实验筒仓随机分配到以下处理（n = 每个 40 个）：1) CON（对照）- 在青贮过程中没有掺入外源酶的再水化玉米青贮饲料；2) AMY——再水化玉米青贮饲料，加入 90 U/kg 新鲜物质的外源 α-淀粉酶；和 3) GLU——再水化玉米青贮饲料，外源性葡糖淀粉酶以 90 U/kg 新鲜物质掺入。结果发现，酶的掺入减少了 DM、淀粉和非纤维碳水化合物，并增加了粗蛋白、醚提取物的总损失和含量。酶的掺入还降低了青贮饲料的 pH 值，同时增加了乳酸浓度。GLU 处理的青贮饲料有更高的好氧细菌数量和乙酸盐和丙酸盐浓度。淀粉分解酶增加了发酵损失和乳酸和乙醇含量，降低了复水玉米青贮饲料的营养价值，