Takahashi Junichi, Iwasa Mitsuhiro
School of Animal and Food Hygiene, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Japan.
Laboratory of Entomology, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Japan.
J Anim Sci Technol. 2021 Jan;63(1):16-24. doi: 10.5187/jast.2021.e11. Epub 2021 Jan 31.
The suppressive effect of monensin as an ionophore-feed additive on enteric methane (CH) emission and renewable methanogenesis were evaluated. To clarify the suppressive effect of monensin a respiratory trial with head cage was performed using Holstein-Friesian steers. Steers were offered high concentrate diets (80% concentrate and 20% hay) with or without monensin, galacto-oligosaccharides (GOS) or L-cysteine. Steers that received monensin containing diet had significantly ( < 0.01) lower enteric CH emissions as well as those that received GOS containing diet ( < 0.05) compared to steers fed control diets. Thermophilic digesters at 55°C that received manure from steers fed on monensin diets had a delay in the initial CH production. Monensin is a strong inhibitor of enteric methanogenesis, but has a negative impact on biogas energy production at short retention times. Effects of the activity of coprophagous insects on CH and nitrous oxide (NO) emissions from cattle dung pats were assessed in anaerobic continuous gas quantification system modified to aerobic quantification device. The CH emission from dungs with adults of Harold (dung beetle) and the larvae of the fly (Fabricius) were compared with that from control dung without insect. The cumulative CH emission rate from dung with dung insects decreased at 42.2% in dung beetles and 77.8% in fly larvae compared to that from control dung without insects. However, the cumulative NO emission rate increased 23.4% in dung beetles even though it reduced 88.6% in fly larvae compared to dung without coprophagous insects. It was suggested that the antibacterial efficacy of ionophores supplemented as a growth promoter still continued even in the digested slurry, consequently, possible environmental contamination with the antibiotics might be active to put the negative impact to land ecosystem involved in greenhouse gas mitigation when the digested slurry was applied to the fields as liquid manure.
评估了莫能菌素作为离子载体饲料添加剂对肠道甲烷（CH）排放和可再生甲烷生成的抑制作用。为了阐明莫能菌素的抑制作用，使用荷斯坦 - 弗里生公牛进行了头部笼养呼吸试验。给公牛提供高浓缩日粮（80%浓缩料和20%干草），添加或不添加莫能菌素、低聚半乳糖（GOS）或L - 半胱氨酸。与饲喂对照日粮的公牛相比，接受含莫能菌素日粮的公牛肠道CH排放量显著降低（<0.01），接受含GOS日粮的公牛也是如此（<0.05）。在55°C下接收饲喂莫能菌素日粮公牛粪便的嗜热消化器，其初始CH产生有延迟。莫能菌素是肠道甲烷生成的强抑制剂，但在短停留时间内对沼气能源生产有负面影响。在改良为需氧定量装置的厌氧连续气体定量系统中，评估了食粪昆虫活动对牛粪堆CH和一氧化二氮（N₂O）排放的影响。将含有哈罗德（蜣螂）成虫和苍蝇（法布里丘斯）幼虫的粪便CH排放与不含昆虫的对照粪便进行比较。与不含昆虫的对照粪便相比，含有粪便昆虫的粪便中，蜣螂的CH累积排放率降低了42.2%，苍蝇幼虫降低了77.8%。然而，与不含食粪昆虫的粪便相比，蜣螂的N₂O累积排放率增加了23.4%，尽管苍蝇幼虫降低了88.6%。有人认为，作为生长促进剂添加的离子载体的抗菌功效在消化后的浆液中仍然持续，因此，当消化后的浆液作为液体肥料施用于田间时，抗生素可能造成的环境污染可能会对参与温室气体减排的陆地生态系统产生负面影响。
