摘要

The emphasis plant breeders place on improving seasonal dry-matter (DM) yield of pasture plants may increase farm profitability through greater supply of DM for livestock in critical seasons. Economic values (EV) for traits can be used to guide plant breeders when selecting top' pasture plants. Two methods of calculating economic value (EV) for seasonal DM traits were evaluated. These were based on the cost of otherwise acquiring or replacing the unit change in DM (replacement cost method') and the opportunity cost of not having the unit change in DM, based on changes in livestock production either as a change in stocking rate or a change in liveweight gains of growing livestock (change in livestock production method'). Using barley replacement cost, the EV of a 1-kg increase in phalaris DM on Australian sheep and beef farms ranged between AUD0234 in summer and AUD0303 in winter. In contrast, the EV for seasonal DM using the change in weaner beef calf liveweight gains ranged between AUD0256 in summer and AUD0515 in winter. The change in livestock production method highlighted in this study offers an alternative to the replacement cost method, or more detailed farm system modelling or experimentations designed to estimate pasture EV.

  • 出版日期2016-3