笋壳与稻壳混合青贮品质动态变化研究

为探讨不同比例笋壳与稻壳混合青贮对青贮饲料发酵品质、营养价值的影响,确定适宜的笋壳与稻壳混合青贮比例,试验设60%笋壳组(A)、70%笋壳组(B)、80%笋壳组(C)、85%笋壳组(D)及100%笋壳组(NC)共5个处理。青贮后第1、7、14、30、45天取样,测定青贮饲料发酵品质及营养成分。结果表明,青贮过程中青贮料的干物质含量有下降趋势,但变化不显著(P>0.05);各组青贮饲料可溶性碳水化合物含量随青贮天数的增加而显著(P<0.05)降低。在青贮过程中,各混合青贮组氨态氮/总氮均显著增高(P<0.05)。青贮第7天时,各组青贮饲料pH均显著下降(P<0.05),此后pH值缓慢变化。各混合青贮组乳酸含量在青贮第7天时显著升高(P<0.05),第14天时持续显著上升(P<0.05),此后乳酸含量基本趋于稳定,并略有降低。各混合青贮组的乙酸含量随青贮发酵时间增加逐渐升高,第7天时显著增加(P<0.05),此后持续缓慢增加。在整个青贮过程中,各组均有少量丙酸产生,处理A、B、C组无丁酸产生。青贮结束时,B组和C组氨态氮/总氮比值低,乳酸含量增加明显,pH低于4.2,青贮过程未产生丁酸,青贮品质优。笋壳单独青贮干物质含量低,乳酸含量低,pH值变化不明显,同时有少量丙酸、丁酸产生,青贮品质差。从发酵品质和笋壳利用最大化的角度出发,建议以80%笋壳+20%稻壳混合青贮较为适宜。

Study on dynamic change of fermentation quality in mixed silages of bamboo shoot shell and rice husk

The objective of this experiment was to evaluate the effects of different proportion of rice husk and bamboo shoot shell(BSS) on the fermentation quality, nutritional value of silage. There were five treatments: 60% BSS(A), 70% BSS(B), 80% BSS(C), 85% BSS(D)and 100% BSS(NC). The silage bottles were opened at 1, 7, 14, 30 and 45 days after ensiling in order to determine the fermentation quality and nutritional compositions of the silages. The results showed that in the silage process, the content of dry material in silage samples decreased, but the change was not significant. The soluble carbohydrate content of each group of silage samples decreased significantly with the increasing of silage days(P<0.05). The ammonia/total nitrogen ratios of each mixed silage group increased significantly during the ensiling(P<0.05). During the ensiling, pH of each group decreased significantly(P<0.05)on the 7th day, thereafter the pH changed slowly. The lactic acid content of samples of each mixed silage group increased significantly on the 7th day of silage(P<0.05), and continued to increase significantly on the 14th day(P<0.05), thereafter the lactic acid content basically stabilized and decreased slightly. The acetic acid content of the samples of each mixed silage group increased gradually with the increase of the fermentation time of silage, increased significantly on the 7th day(P<0.05), and continued to increase slowly thereafter. Throughout the silage process, a small amount of propanoic acid was produced in each group, and no butyric acid was produced in A, B, C treatments. At the end of silage, for B and C treatments, ammonia/total nitrogen ratios were low, lactic acid content increased significantly, pH was lower than 4.2, no butyric acid was produced in the silage process, and silage quality was good. In conclusion, from the present study,that mixing 80% bamboo shoot shell and 20% rice husk was recommended for fermentation quality and utilization efficacy.