An Evaluation of the Cattle Raising Business in Miyakojima Island
Abstract
This paper clarifies the material flow of the following four types of Wagyu cattle raising in Miyakojima: 1) calves (younger than 10 months age), 2) adult cattle ( raised for 20 months after less than 10 month raising ), 3) breeding cows (giving birth to calves) and 4) breeding cows which cannot give a birth to calves (after 10 times calving). The cattle raising business in Miyakojima Island focuses on the raising of types given in 1) and 3). The breeding cows in 1) and 3) can be raised by pasturages which are available on the island. For the other types, imported feeds need to be used. The Material Flow Analysis this paper implements shows how much nitrogen, carbon and phosphorus are consumed and show the quantity of resources used on the island. This paper also clarifies how much stool and urine is generated by cattle raising. The efforts to clarify the quantity of stool and urine was not made in past research. Miyakojima depends on ground water for drinking water and the urine and stool from cattle raising poses a threat to the safe use of ground water. The quantity of stool and urine can be the key information in planning water quality conservation programs. The methodology to conduct the material flow analysis is shown in this paper: what information should be required; who needs to be contacted; what formulae are used; what require elemental analysis. Two conversion factors are adopted to obtain the nitrogen and the carbon content from the information available in the cattle raising business. In the material flow analysis, the mass balance of nitrogen, carbon and phosphorus is performed.