Project number: 2004-220
Project Status:
Completed
Budget expenditure: $1,012,905.00
Principal Investigator: Geoff Allan
Organisation: NSW Department Of Primary Industries
Project start/end date: 29 Sep 2004 - 30 May 2009
Contact:
FRDC

Need

Temperate marine fish farmers in Australia seek to have the option to choose between several species of fish based on market price, availability and cost of fingerlings and health and feeding costs. This need was identified at the Aquafin CRC workshop held in 2002 (Allan, 2003). Most research on temperate marine finfish has been conducted on snapper (Pagrus auratus) but farmers are now concentrating more on yellowtail (Seriola lalandi) and mulloway (Argyrosomus japonicus) with significant interest in yellowfin bream (Acanthopagrus australis). Applied research is needed, particularly on the major cost areas of diets and feeding (for both fingerlings and grow-out fish) to help ensure profitability and to give farmers and feed manufacturers information so they can make informed business decisions.

Costs of feeds and feeding are usually the largest budget expense for marine fish farms and also significantly affect costs of producing fingerlings in hatcheries. In hatcheries, the global shortage of Artemia and the huge cost of weaning diets has led to a increased priority for better and cheaper live feeds, formulated weaning diets and feeding strategies. For grow-out, most farmers want high-performance, low-cost feeds. Given a choice, most farmers will pay more for diets to achieve better performance but have no real way to make decisions to achieve the most cost effective feeding strategy. There is a clear lack of information for most temperate marine species about the nutritional specifications needed for high performance diets and what physical characteristics are most desirable in the pellets (e.g. should pellets be floating or sinking, how important is pellet hardness, etc). This prevents feed manufacturers providing data-based recommendations about the best diets for farmers and prevents them from formulating and manufacturing specific diets for temperate marine finfish farmed in Australia. Unfortunately, the same lack of information is restricting choices about the ingredients being used in diets. Almost no information exists about digestibility or utilization of most of the ingredients available for use in Australia aquafeeds. Most farmers are aware of “problems” with the use of terrestrial animal protein meals in animal feeds and that use of such ingredients might negatively affect the export market for their fish. However, apart from research with snapper (Aquafin CRC; WA Fisheries) and barramundi (FRDC ADD Subprogram; WA Fisheries) there is no information about digestibility or utilization of Australian ingredients for temperate marine finfish being farmed in Australia. The immediate result of this lack of information is an increase in the proportion of expensive, imported fishmeal being used in diets.

This project will extend the successful research approach adopted for snapper in Aquafin CRC Project 1B.3-2001/208 (Increasing the profitability of snapper farming by improving hatchery practices and diets). In that project, fingerling costs were reduced by approximately 30% through systematic research to develop more cost-effective hatchery procedures including the demonstration of the feasibility of replacing live feeds including artemia with alternative live feeds (copepods) and/or commercially available, inert pellet diets for advanced snapper larvae. Previous work with snapper also demonstrated a major improvement in growth of juvenile snapper when the optimal feeding frequency and day-length were identified. This project seeks to reduce feed costs, to optimise feeding efficiency and to improve fingerling survival and growth of mulloway and yellowtail. Sub-optimal performance of marine fish larvae is often a result of inadequate nutrition or sub-optimal physio-chemical variables during larval rearing. A high percentage of slow-growing or stunted fish in larval rearing runs can seriously reduce economic viability of hatcheries and increase farming costs. The performance of larvae has not been addressed in a systematic manner and although the commercial hatcheries in SA report that fingerling production is not a barrier, there are no published methods of how to optimize production of fingerlings (i.e. to to increase cost-effectiveness of fingerling production). This lack of information will reduce the chance of expanding marine fish farming in NSW and other states in Australia.

Existing grow-out diets used for marine fish such as yellowtail, mulloway and bream are based on generic formulations for “marine fish” (including salmon and barramundi). These diets produce results but it is unknown if current diets are nutritionally adequate, especially for rapidly growing fish. Even basic requirements, like the best protein to energy ratio, are unknown for yellowtail and mulloway. Both low and high energy diets are available for salmon and barramundi but even simple comparisons to find the best of these two “options” have not yet been carried out. There is no reliable information on ingredient digestibility making it impossible for feed manufacturers to confidently formulate diets with alternative protein sources to fishmeal when fishmeal is hard to obtain and when prices are high (and, of course, fish meal prices continue to rise). Research to provide this information is urgently needed.

There are obvious problems with a "one-species at a time" approach to diet development research. This is expensive and takes a long time. This application seeks to conduct specific research with mulloway and kingfish and to build comprehensive models of nutritional requirements for these two species that can be directly compared with other similar models now available for other marine and freshwater aquaculture species (e.g. snapper, sea bream and barramundi).

Fingerling costs for mulloway and kingfish are currently estimated at $0.60->$2.00/fingerling. These represent well in excess of 10% of operating costs. We aim to reduce these costs by as much as 50%. Growout feeds can cost in excess of $2,000/t and with the costs of feeding are usually in excess of 30% of total operating costs (>50% for some operations). Food conversion ratios of in excess of 1.5:1 are regularly reported. We aim to produce diets with FCRs of 1.2:1 with approximately 25% lower ingredient costs. Together these represent the major areas where improvements in production technology can improve the profitability of marine fish farming.

Objectives

1. To reduce costs of fingerling production
2. To improve the cost-effectiveness of grow-out diets
3. To validate improved feeds and feeding practices on a commercial scale

Final report

ISBN: 9780980837704
Author: Geoff Allan
Final Report • 2011-03-10 • 4.77 MB
2004-220-DLD.pdf

Summary

The report is presented in two volumes Aquafin CRC – Feed Technology Temperature Fish Species: Volume 1: Feeding Strategies and Volume 2: Diet Development.  The volumes share common background, need, overall objectives, benefits and adoption, further development, planned outcomes, intellectual property and staff.  They have individual non-technical summaries, results and discussions and conclusions.  

Mulloway (Argyrosomus japonicus) were first bred in Australia by the team at Port Stephens Fisheries Institute in NSW in 1992.  This species has attracted considerable aquaculture potential due to its almost Australia-wide distribution and fast growth rates.  Commercial grow-out of this species is occurring in New South Wales and South Australia.  There was zero production in 2000/01 and combined production in 2001/02 was only 46 t. Production of mulloway increased quickly to over 600 t per annum in 2006/07 (although this dropped off to 309 in 2007/08) and yellowtail kingfish (Seriola lalandi) increased to 3,370 t per annum (2007/08). Interest in mulloway has declined in favour of yellowtail kingfish. One notable difference between mulloway and kingfish is their feeding behaviour.  Kingfish feed actively on the surface while mulloway are sub-surface feeders.  Changing buoyancy of feeds is possible using extrusion technology but can restrict ingredient choice.

Temperate marine fish farmers in Australia seek to have the option to choose between several species of fish based on market price, availability and cost of fingerlings, health and feeding costs. This need was identified at the Aquafin CRC workshop held in 2002. At that time, most commercial and research interest on temperate marine finfish was with snapper (Pagrus auratus) but farmers moved quickly to yellowtail kingfish and mulloway.  Applied research is needed, particularly on the major cost areas of diets and feeding (for both fingerlings and grow-out fish) to help ensure profitability and to give farmers and feed manufacturers information so they can make informed business decisions. 

In hatcheries, the global shortage of Artemia and the huge cost of weaning diets led to a increased priority for better and cheaper live feeds, formulated weaning diets and feeding strategies.  This project was designed to extend the successful research approach adopted for snapper in Aquafin CRC Project 1B.3-2001/208 (Increasing the profitability of snapper farming by improving hatchery practices and diets).  In that project, fingerling costs were reduced by approximately 30% through systematic research to develop more cost-effective hatchery procedures including the demonstration of the feasibility of replacing live feeds including Artemia with alternative live feeds (copepods) and/or commercially available, inert pellet diets for advanced snapper larvae. Previous work with snapper also demonstrated a major improvement in growth of juvenile snapper when the optimal feeding frequency and day-length were identified. This project reduced feed costs, optimised feeding efficiency and improved fingerling survival and growth of mulloway.  Similar research with yellowtail kingfish was also conducted. Sub-optimal performance of marine fish larvae is often a result of inadequate nutrition or sub-optimal physico-chemical variables during larval rearing.  A high percentage of slow-growing or stunted fish in larval rearing runs can seriously reduce economic viability of hatcheries and increase farming costs.  The performance of larvae has not previously been addressed in a systematic manner. Results from the research discussed in this report have been used to develop practical hatchery manuals for mulloway and yellowtail kingfish.  

Keywords: Mulloway; Yellowtail kingfish; Feeding Strategies; Larval rearing; Ozonation; Photoperiod.

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