CAS Key Laboratory of Agro-Ecological Processes in Subtropical Region, Hunan Research Center of Livestock and Poultry Sciences, South Central Experimental Station of Animal Nutrition and Feed Science in the Ministry of Agriculture, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, China.
University of the Chinese Academy of Sciences, Beijing, China.
J Sci Food Agric. 2018 Nov;98(14):5205-5211. doi: 10.1002/jsfa.9056. Epub 2018 May 28.
Urea pretreatment of straw damages fiber structure, while nitrate supplementation of ruminal diets inhibits enteric methane production. The study examined the combined effects of these treatments on ruminal substrate biodegradation and methane production using an in vitro incubation system. Rice and wheat straws were pretreated with urea (40 g kg straw dry matter, DM) and urea + ammonium nitrate (34 + 6 g kg dry matter (DM), respectively), and each straw (control, urea, urea+nitrate) was used in batch culture incubations in three replications (runs).
Urea pretreatment increased (P < 0.05) neutral-detergent solubles (NDS) content (+17%) and in vitro DM degradation of rice straw, in comparison with control. Urea+nitrate pretreatment of rice and wheat straws had higher (P < 0.05) NDS content, in vitro DM degradation and propionate molar proportion, and lower (P < 0.05) acetate:propionate ratio and lower methane production with a decline of methanogens, in comparison to control.
Urea+nitrate pretreatment combines positive effects of urea pretreatment and nitrate supplementation, and can be a potential strategy to improve ruminal biodegradation, facilitate propionate production and reduce methane production from lignified straws. © 2018 Society of Chemical Industry.
秸秆的尿素预处理会破坏纤维结构，而瘤胃日粮中添加硝酸盐会抑制肠道甲烷的产生。本研究使用体外孵育系统，研究了这些处理方法对瘤胃底物生物降解和甲烷生成的综合影响。用尿素（稻草干物质 40 g/kg）和尿素+硝酸铵（分别为 34+6 g/kg 干物质）预处理水稻和小麦秸秆，每种秸秆（对照、尿素、尿素+硝酸盐）在三个重复（运行）的分批培养孵育中使用。
与对照相比，尿素预处理增加了（P<0.05）中性洗涤剂可溶物（NDS）含量（增加 17%）和水稻秸秆的体外 DM 降解。与对照相比，水稻和小麦秸秆的尿素+硝酸盐预处理具有更高的（P<0.05）NDS 含量、体外 DM 降解和丙酸摩尔比例，以及更低的（P<0.05）乙酸：丙酸比和更低的甲烷产量，甲烷生成菌下降。
尿素+硝酸盐预处理结合了尿素预处理和硝酸盐补充的积极作用，可能是提高木质化秸秆瘤胃生物降解、促进丙酸生成和减少甲烷生成的一种潜在策略。© 2018 英国化学学会。
