Prelimary Comparisons of Yield and Profit Achieved from DifferentRainbow Trout, Oncorhynchus mykiss, Production Systems in InlandWestern Austrailia

摘要

Farmers throughout the wheatbelt of Western Australia are interested in farming rainbow trout, Oncorhynchus mykiss, in saline groundwater on salt-affected farmland, to generate an alternative source of income. We compared the relative productivity and profitability of three different production systems: extensive (trout stocked in earthen ponds and totally reliant on natural food); semi-intensive (trout stocked in earthen ponds and provided with supplementary diet); intensive (trout stocked in closed, recirculating tanks). The yield of fish increased with increasing production intensity. The mean wet weight ( plus or minus SE) of trout after 4 months of growout was 61.3 plus or minus 2.7g in extensive systems, 157.9 plus or minus 5.2g in semi-intensive systems and 137.9 plus or minus 3.9 g in intesive systems, giving mean yields of 10.8 kg/pond (13.5 kg/ha), 27.9 kg/pond (34.8 kg/ha) and 54.9 kg/tank (21.1 kg/m super(3)), respectively. A preliminary economic analysis of the different production systems showed that the increases in yield were sufficient to balance the extra operating costs involved in semi-intensive systems, but not in intensive systems. We conclude that semi-intensive production systems deserve further study for the commercially viable production of rainbow trout from saline groundwater in Western Australia.