반추동물 장내발효 메탄가스 측정을 위한 호흡대사챔버의 개발

Methane, which is one of major greenhouse gases, is produced from enteric fermentation in ruminants. Methane emissions from ruminants are responsible for more than 40% of total greenhouse gas emissions in the livestock sector in the Republic of Korea. Therefore, many researchers have attempted to reduce methane emissions from ruminants. In the present study, we developed a respiration metabolic chamber to measure methane emissions from ruminants and evaluated its accuracy. The respiration metabolic chamber was made 25.4 m3 in size and was completely sealed with a stainless steel plate. An air inlet and discharge pipe with 100 mm diameter was installed in top of chamber, and the same amount of air discharged was entered into the chamber from the outside. For the recovery test, the methane standard gas (5L) was injected into each chamber with uniform diffusion, and air in the chamber was removed at a rate of 900 L/min. The recovery rate(%) was calculated by methane gas concentration of the removed air and comparing it with the injected standard methane gas. The standard gas in the chamber was removed in about 130 minutes, and the recovery rate of methane gas was measured as 109 ± 6.7% on the average. In order to evaluate applicability of the respiration metabolic chamber, methane emission was measured using 4 Hanwoo steers (581.9 ± 33.8 kg), which were fed 9 kg of concentrate and 1 kg of rice straw. The amount of methane emission from Hanwoo was measured to be 236.4 ± 105.44 L/day on average. The respiration metabolic chamber developed and verified in the present study will be applicable for the measurement of methane gas emissions from Hanwoo cattle.