Li Ping, You Minghong, Du Zhouhe, Lu Yongxiang, Zuo Chunyan, Zhao Man, Wang Honglin, Yan Xu, Chen Chao
College of Animal Science, Guizhou University, Guiyang, China.
Grass and Forage Research Institute, Sichuan Academy of Grassland Sciences, Chengdu, China.
Front Microbiol. 2021 Oct 7;12:735767. doi: 10.3389/fmicb.2021.735767. eCollection 2021.
As unconventional forage source, mulberry ( L.) has been cultivated to alleviate animal feed shortages. This study aimed to investigate the effects of N fertilization during cultivation and inoculation at ensiling on the chemical composition and bacterial community of mulberry silage. Mulberry was separately cultivated under two N fertilization rates (N1, 390 kg/ha/year; N2, 485 kg/ha/year) in 2016-2019, harvested on 30 April (the first-cut) and 15 June (the second-cut) in 2019, and then chopped for producing small bag silage. The silage was treated without (control) or with (LP, a recommended application rate of 10 cfu/g on fresh matter basis). After storage of 60 days in dark room at ambient temperature, silage was sampled for analysis of chemical and microbial compositions. Higher ( < 0.05) final pH value and acetic acid content and lower ( < 0.05) lactic acid content were found in silage of mulberry under N2 fertilization, resulting in more dry matter loss than that under N1 fertilization. Compared with control, inoculation of LP at ensiling increased ( < 0.05) lactic acid content and decreased ( < 0.05) final pH value, acetic acid and propionic acid contents of silage, by advancing the dominance of and reducing the abundance of and . In particular, inoculation of LP at ensiling decreased ( < 0.05) dry matter loss and butyric acid content of first-cut silage. In conclusion, inoculation of LP at ensiling could reduce the undesirable effects from high N fertilization rate during cultivation on silage quality of mulberry harvested at different growing seasons.
作为一种非常规饲料来源，桑树（桑属）已被种植以缓解动物饲料短缺问题。本研究旨在探讨栽培过程中施氮和青贮时接种对桑青贮饲料化学成分和细菌群落的影响。2016 - 2019年，桑树分别在两种施氮水平（N1，390千克/公顷/年；N2，485千克/公顷/年）下种植，于2019年4月30日（头茬收割）和6月15日（二茬收割）收获，然后切碎用于制作小袋青贮饲料。青贮饲料不处理（对照）或用LP处理（推荐施用量为每克鲜物质10 cfu）。在室温黑暗环境中储存60天后，采集青贮饲料样本分析其化学和微生物组成。发现N2施肥处理的桑青贮饲料最终pH值和乙酸含量较高（P < 0.05），乳酸含量较低（P < 0.05），导致干物质损失比N1施肥处理的更多。与对照相比，青贮时接种LP增加了（P < 0.05）青贮饲料的乳酸含量，降低了（P < 0.05）最终pH值、乙酸和丙酸含量，通过促进优势菌的生长并减少有害菌的丰度。特别是，青贮时接种LP降低了（P < 0.05）头茬青贮饲料的干物质损失和丁酸含量。总之，青贮时接种LP可以减少栽培过程中高施氮量对不同生长季节收获的桑青贮饲料质量产生的不良影响。
