Fermentation characteristics and bromatological composition of sweet sorghum bagasse silages

SUMARY The aim of this study was to evaluate conservation characteristics of sweet sorghum bagasse silages. The experiment was carried out at Fazenda Rio Manso, an experimental unit of the Federal University of the Jequitinhonha and Mucuri Valleys. Twenty-five sorghum cultivars with three replicates were used in a completely randomized design. The juice was extracted from the plant through an electric mill, generating bagasse, which was ground in a stationary silage machine, added of its panicles, and then introduced into experimental silos. Silages of the varieties BR505; CMSXS629; CMSXS635; CMSXS639; CMSXS643; CMSXS646; V82391 and V82392 presented lower rate of total dry matter recovery and, consequently, higher gas losses. The means of dry matter contents of bagasse and silage were 32.80 and 28.55%, respectively. The cultivars BR501; XBSW80147; BR505; CMSXS629; CMSXS633; CMSXS634; CMSXS635; CMSXS639; CMSXS643; CMSXS644; CMSXS648; BRS601; Sugargraze; V82391; V82392 and V82393 showed higher crude protein levels. The cultivar CMSXS642 presented lower neutral and acid detergent fiber content: 39.23 and 19.23%, respectively. The cultivar XBSW80147 showed lower acid detergent fiber content. Means of 3.49 for pH and 0.96 for water activity were recorded. The cultivars BR501 and BRS601 showed higher values of electrical conductivity: 0.93 and 0.95 S/cm, respectively. Higher levels of ammoniacal nitrogen were only observed in cultivars BR501; CMSXS629; CMSXS636; CMSXS648 and V82392. Sorghum bagasse silages presented adequate conservation inside the silos, according to the evaluated variables.

摘要：本研究旨在评估甜高粱渣粕青贮饲料的贮藏特性。试验在热基通哈与穆库里河谷联邦大学的实验基地里奥曼索农场（Fazenda Rio Manso）开展。本试验采用完全随机设计，共设置25个高粱品种，每个品种设置3次重复。通过电动研磨机从植株中榨取汁液，得到甜高粱渣粕（bagasse），随后将渣粕置于固定式青贮机中粉碎，并添加自身穗部，之后装入试验青贮窖中。BR505、CMSXS629、CMSXS635、CMSXS639、CMSXS643、CMSXS646、V82391及V82392等品种的青贮饲料总干物质回收率（dry matter recovery）较低，因此气体损失率较高。甜高粱渣粕与青贮饲料的干物质含量平均值分别为32.80%与28.55%。BR501、XBSW80147、BR505、CMSXS629、CMSXS633、CMSXS634、CMSXS635、CMSXS639、CMSXS643、CMSXS644、CMSXS648、BRS601、Sugargraze、V82391、V82392及V82393等品种的粗蛋白（crude protein）含量较高。CMSXS642品种的中性洗涤纤维（neutral detergent fiber）与酸性洗涤纤维（acid detergent fiber）含量最低，分别为39.23%与19.23%。XBSW80147品种的酸性洗涤纤维含量最低。试验测得pH平均值为3.49，水分活度（water activity）平均值为0.96。BR501与BRS601品种的电导率（electrical conductivity）较高，分别为0.93 S/cm与0.95 S/cm。仅在BR501、CMSXS629、CMSXS636、CMSXS648及V82392等品种中检测到较高水平的氨态氮（ammoniacal nitrogen）。综合各测定指标来看，甜高粱渣粕青贮饲料在青贮窖内的贮藏效果良好。