In situ ruminal degradability of silages of elephant grass additivated with corn bran and inoculation of autochthonous microbiota

This study aimed to evaluate the in situ degradability of dry matter, crude protein and neutral detergent fiber of elephant grass silage with corn bran and inoculation of autochthonous microbiota. For the silages used a 4 x 2 factorial arrangement (four levels of corn bran - 0, 5, 10 and 20dag/kg x with and without inoculation) and five replications, in a completely randomized design. In degradability trial, the experimental design was a randomized block, split plot in which three animals represented the blocks; silages represent the treatments, and the seven incubation times of food in the rumen (0, 6, 12, 24, 48, 96 and 144 hours), the subplots. With the addition of corn bran was increase the soluble fraction in the silages, and so treatments with 20dag/kg of corn bran resulted in higher values of the soluble fraction of the dry matter, 31.49 and 29.02%, for treatments with and without inoculant, respectively. The insoluble potentially degradable fraction of dry matter was higher in silages with 20 dag/kg of corn bran. In neutral detergent fiber, higher values of insoluble potentially degradable fraction were observed in the silage without corn bran, 56.52 and 57.19%, respectively, in the silages with and without inoculation of autochthonous microbiota. The addition of corn bran of elephant improves dry matter degradability of silages and decreases of neutral detergent fiber.本研究旨在评估添加玉米麸皮并接种本土微生物群（autochthonous microbiota）的象草青贮饲料的干物质、粗蛋白及中性洗涤纤维（neutral detergent fiber）的原位降解特性（in situ degradability）。本试验采用4×2因子设计，设置4个玉米麸皮添加水平（0、5、10、20dag/kg）与2个接种处理（接种与不接种微生物群），采用完全随机设计，设置5次重复。降解试验采用随机区组裂区设计，以3头试验动物作为区组，青贮饲料为处理因素，食物在瘤胃（rumen）内的7个孵育时间（0、6、12、24、48、96和144小时）作为副区组。添加玉米麸皮可提升青贮饲料的可溶性组分比例；其中添加20dag/kg玉米麸皮的处理组，无论是否接种微生物群，其干物质可溶性组分比例均为最高，分别达31.49%与29.02%。干物质的潜在不溶性可降解组分比例在添加20dag/kg玉米麸皮的青贮饲料中更高。就中性洗涤纤维而言，未添加玉米麸皮的青贮饲料的潜在不溶性可降解组分比例更高，接种与不接种本土微生物群的组别分别为56.52%与57.19%。向象草青贮饲料中添加玉米麸皮可提升其干物质降解率，并降低其中性洗涤纤维的相关降解指标。