Abstract
Sustainable cattle production systems should be environmentally sound and economically viable. In this study, a possible relationship between environmental and economic sustainability was assessed for three production systems ; dairy (Holstein) system, dairy cow-F1 calf (crossbred between Japanese Black sire and Holstein dam) system and dairy cow-F1 feedlot system. It was assumed that F1 calves are sold at 2 months of age in the second system and fattened until slaughtered in the third system. Modeling herd dynamics and economic analysis were conducted based on field data concerning feeding practice, reproductive management, production and commercialization of products (milk, calf and/or carcass) collected by interview survey on farms in the target region. Environmental impacts were evaluated with life cycle assessment, and potential impact categories assessed in this study were global warming, acidification, eutrophication and energy use. The benefit (sale minus cost) per environmental impacts was used as an indicator for evaluating both environmental and economic sustainabilities. The results showed that dairy cow-F1 feedlot systems be economically most favorable because of high benefit from high priced carcass, but environmentally worst due to large environmental impacts caused by the long feedlot period. The dairy cow-F1 calf system was suggested as the best system from environmental and economic points of view in this study.
