ACIAR Project FIS/97/73 - Library - Network of Aquaculture Centres ...

Survival ranged from 83–97% and did not differ significantly among treatments.Feed conversion efficiency was best at 30% fish-meal replacement and poorest at80% fish meal replacement. Fish fed the diets containing the three highest fish mealreplacement levels (60–100% meat solubles) exhibited significantly lower growth andinefficient feed conversion compared to the control group. These results indicate thatwhile partial replacement of fish meal with meat solubles may be practical for grouperdiets, total replacement may result in significant degradation of growth rate and feedconversion. Full details of this experimental work are appended (Appendix 3).Research at RSCF Gondol with C. altivelis has demonstrated that there is a limitedcapacity to replace fish-meal with non-animal protein in this species. Fiveexperimental diets containing different levels of soybean meal (0, 10, 20, 30 and 40%)and fish meal (63, 55.3, 47.6, 39.9 and 32.2%) were prepared as dry pellet. Dietswere isonitrogenous (51% CP) and isocaloric (4.4 kcal/100 g diet). Polycarbonatetanks of 30-litre volume were each stocked with 11 fish (3.0 ± 0.02 g) , and theexperimental diet fed three times daily to satiation for 35 days. Results of theexperiment showed that fish fed diet containing 10% soybean meal had the highestweight gain and feed efficiency. Inclusion of 20% or more soybean meal in the dietsignificantly retarded the growth of fish.3.5 Diet validationThis component has not yet commenced. Diet validation work will be undertakenlater in the project when further laboratory studies of diet composition and nutritionhave been completed.3.6 Economic evaluationBill Johnston (DPI) has drafted separate economic models for the three major phases ofgrouper aquaculture:1 Hatchery;2 Nursery;3 Grow-out (in ponds and cages).The models are written in Excel 97 ® and provide a detailed assessment of the capitaland operating costs for each phase of grouper aquaculture. Outputs include abreakdown of annual costs and a profitability analysis (using a discounted cash flowmodel).These models will be provided to participating institutions at the project meeting inCairns in late July. Bill will run through the models at that meeting to demonstrate themethod of operation. The second stage of the economic evaluation will be forparticipating institutions to check that the components of the model are applicable tohatcheries, nurseries and grow-out farms in their country. In addition, we need todevelop ‘model farms’ for Australia, Indonesia and the Philippines. These farmmodels will be used to evaluate the economic impact of our research on grouperaquaculture in each of the participating countries. More evolved versions of theeconomic models will be widely distributed through the Asia-Pacific GrouperNetwork.4 Communication and coordinationThe communication and coordination component of the project was developed from arecommendation of the Grouper Aquaculture Research Workshop held in Bangkok in1998 that communication and coordination between grouper aquaculture researchersACIAR Project FIS/97/73 – Annual Report – June 2000 18