Agriculture and Agri-Food Canada, Sherbrooke Research and Development Centre, 2000 College Street, Sherbrooke, QC, Canada J1M 0C8.
Agriculture and Agri-Food Canada, Sherbrooke Research and Development Centre, 2000 College Street, Sherbrooke, QC, Canada J1M 0C8.
J Dairy Sci. 2019 Nov;102(11):10632-10638. doi: 10.3168/jds.2019-16822. Epub 2019 Aug 30.
The objective of this study was to examine the effects of feeding conventional corn silage (CCS) or brown midrib corn silage (BMCS) to dairy cows on CH emissions from stored manure. Eight lactating cows were fed (ad libitum) a total mixed ration (forage:concentrate ratio 65:35; dry matter basis) containing 59% (dry matter basis) of either CCS or BMCS. Feces and urine were collected from each cow and mixed with residual sludge obtained from a manure storage structure. Manure was incubated for 17 wk at 20°C under anaerobic conditions (O-free N) in 500-mL glass bottles. Methane emissions and changes in chemical composition of the manure were monitored during the incubation period. The total amount of feces and urine excreted was higher for cows fed BMCS than for cows fed CCS [8.6 vs. 6.5 kg/d of volatile solids (VS)]. Manure from cows fed BMCS emitted more CH than manure from cows fed CCS (173 vs. 146 L/kg of VS) throughout the incubation period. Similarly, VS and neutral detergent fiber losses throughout incubation were higher for manure from cows fed BMCS versus cows fed CCS (37.6 vs. 30.6% and 46.2 vs. 31.2%, respectively). Manure NH concentration (79% of total manure N) was not affected by corn silage cultivar. Results of this study show that using a more digestible corn silage cultivar (BMCS vs. CCS) may increase the contribution of manure to CH emissions, and may offset gain achieved by reducing enteric CH emissions.
本研究旨在探讨奶牛采食常规玉米青贮（CCS）或棕色硬质玉米青贮（BMCS）对贮存粪污中 CH 排放的影响。8 头泌乳奶牛自由采食以 CCS 或 BMCS 为基础日粮的全混合日粮（饲草：精料比例 65:35；干物质基础），其中 59%（干物质基础）为饲草。从每头奶牛中收集粪便和尿液，并与从粪污贮存结构中获得的剩余污泥混合。在 20°C、无氧（无游离氮）条件下，将粪污在 500-mL 玻璃瓶中培养 17 周。在培养期间监测 CH 排放和粪污化学成分的变化。与采食 CCS 的奶牛相比，采食 BMCS 的奶牛的粪便和尿液排泄总量更高[8.6 比 6.5 kg/d 挥发性固体（VS）]。整个培养期间，采食 BMCS 的奶牛的粪污比采食 CCS 的奶牛排放更多的 CH（173 比 146 L/kg VS）。同样，与采食 CCS 的奶牛相比，采食 BMCS 的奶牛的 VS 和中性洗涤剂纤维在整个培养期间的损失更高（37.6 比 30.6%和 46.2 比 31.2%）。粪污 NH 浓度（总粪污氮的 79%）不受玉米青贮品种的影响。本研究结果表明，使用更易消化的玉米青贮品种（BMCS 比 CCS）可能会增加粪污对 CH 排放的贡献，并且可能会抵消通过减少肠道 CH 排放而获得的收益。
