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 (336Kb)
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16,232,000 Yen (FY1997;5,333,000 Yen)
Methane and Nitrous oxide are classified as greenhouse-effect gasses. This study aimed at improving accuracy to estimate the production of these gasses from ruminants and examining factors involved in the production in order to obtain basic information for the reduction of these gasses. The results obtained from a series of studies on methane emission and factors affecting its production are as follows: 1)Methane production from cattle changes in relation to either milk yield or body weight gain. Therefore, methane emission per cattle products could be largely cut down by an improvement of productivity. It was pointed out by a further quantitatively analysis of the relationship between these factors that methane emission clearly decreased when cattle was given large amount of concentrate in the case of beef fattening. 2)Methane production from ruminants is affected by feed composition and environmental temperature.
Results regarding emission of nitrous oxide are as follows: 1)Nitrous oxide is hardly produced in rumen under conventional feeding systems. The emission from feces and urine in a cattle barn is also negligible. 2)Major part of nitrous-oxide-gas emission from livestock occurs during the process of making compost either from solid or liquid part of manure. It became clear by examining factors involved in nitrogen excretion from dairy and beef cattle that improvement of productivity and the reduction of nitrogen supply are effective for the reduction of nitrogen excretion.
Ruminants, Methane, Nitrous oxide, Nitrogen excretion, Milk yield