Sarker Niloy Chandra, Keomanivong Faithe, Borhan Md, Rahman Shafiqur, Swanson Kendall
1Agricultural and Biosystems Engineering Department, North Dakota State University, Fargo, ND 58108 USA.
2Animal Sciences Department, North Dakota State University, Fargo, ND 58108 USA.
J Anim Sci Technol. 2018 Nov 9;60:27. doi: 10.1186/s40781-018-0185-5. eCollection 2018.
Enteric methane (CH) accounts for about 70% of total CH emissions from the ruminant animals. Researchers are exploring ways to mitigate enteric CH emissions from ruminants. Recently, nano zinc oxide (nZnO) has shown potential in reducing CH and hydrogen sulfide (HS) production from the liquid manure under anaerobic storage conditions. Four different levels of nZnO and two types of feed were mixed with rumen fluid to investigate the efficacy of nZnO in mitigating gaseous production.
All experiments with four replicates were conducted in batches in 250 mL glass bottles paired with the ANKOM wireless gas production monitoring system. Gas production was monitored continuously for 72 h at a constant temperature of 39 ± 1 °C in a water bath. Headspace gas samples were collected using gas-tight syringes from the Tedlar bags connected to the glass bottles and analyzed for greenhouse gases (CH and carbon dioxide-CO) and HS concentrations. CH and CO gas concentrations were analyzed using an SRI-8610 Gas Chromatograph and HS concentrations were measured using a Jerome 631X meter. At the same time, substrate (i.e. mixed rumen fluid+ NP treatment+ feed composite) samples were collected from the glass bottles at the beginning and at the end of an experiment for bacterial counts, and volatile fatty acids (VFAs) analysis.
Compared to the control treatment the HS and GHGs concentration reduction after 72 h of the tested nZnO levels varied between 4.89 to 53.65%. Additionally, 0.47 to 22.21% microbial population reduction was observed from the applied nZnO treatments. Application of nZnO at a rate of 1000 μg g have exhibited the highest amount of concentration reductions for all three gases and microbial population.
Results suggest that both 500 and 1000 μg g nZnO application levels have the potential to reduce GHG and HS concentrations.
反刍动物肠道甲烷（CH）约占其总CH排放量的70%。研究人员正在探索减轻反刍动物肠道CH排放的方法。最近，纳米氧化锌（nZnO）已显示出在厌氧储存条件下减少液体粪便中CH和硫化氢（HS）产生的潜力。将四种不同水平的nZnO与两种类型的饲料与瘤胃液混合，以研究nZnO减轻气体产生的效果。
所有实验均进行四次重复，在250 mL玻璃瓶中分批进行，并与ANKOM无线气体产生监测系统配对。在39±1°C的恒温水浴中连续监测气体产生72小时。使用气密注射器从连接到玻璃瓶的Tedlar袋中采集顶空气体样本，并分析温室气体（CH和二氧化碳-CO）以及HS浓度。使用SRI-8610气相色谱仪分析CH和CO气体浓度，使用Jerome 631X仪表测量HS浓度。同时，在实验开始和结束时从玻璃瓶中采集底物（即混合瘤胃液+NP处理+饲料复合物）样本，用于细菌计数和挥发性脂肪酸（VFA）分析。
与对照处理相比，测试的nZnO水平在72小时后HS和温室气体浓度降低幅度在4.89%至53.65%之间。此外，在所应用的nZnO处理中观察到微生物数量减少了0.47%至22.21%。以1000μg/g的速率施用nZnO对所有三种气体和微生物数量的浓度降低量最高。
结果表明，500μg/g和1000μg/g的nZnO施用水平都有降低温室气体和HS浓度的潜力。
