Boosting Redclaw Industry Productivity With Improved Nutrition & Feed Management
James Cook University
Project code: PRJ-008536
Project stage: Closed
Project start date: Saturday, August 18, 2012
Project completion date: Thursday, December 31, 2015
National Priority: NAP-Enhance industry success through targeted industry-specific RD&E
Commercial farming of the freshwater crayfish, redclaw, is a small but dedicated industry in tropical rural Australia producing 60 t annually worth around $1,000,000. To date industry growth has stagnated due to a lack of reliable information on nutritional requirements and the availability of an industry feeding standard. The costs of feeds and feeding in intensive aquaculture represent the greatest proportion of ongoing expenses in farm operations. Getting these wrong detrimentally impacts budgets reducing profitability and overall growth; this has been a major cause of concern for redclaw farmers for many years and presents a significant bottleneck to the development of the industry.
Suggested dietary requirements for redclaw aren’t very informative and vary considerably with “optimal” crude protein ranging anywhere from 13-43%. To date there has been no work quantifying the ontogenic shift in requirements for dietary protein and energy. As a detritivore, redclaw will likely have the capacity to utilize a wide range of low-cost plant-based materials as dietary energy sources yet there has been little work published examining alternative feed ingredients for this species.
This project will build on the important groundwork laid during Phase I RIRDC project PRJ-004960. Specifically, the aim is to determine the requirements for digestible protein and energy, assess the suitability of alternative feed ingredients and develop a practical feeding standard. This will be achieved using combination of nutritional modeling, feeding behaviour studies and radio isotope techniques. This information will assist Australian redclaw farmers in making informed decisions on appropriate feed management strategies.
New and Emerging Animal Industries
James Cook University
The overall objectives of the proposed research project are to:
i) determine the nutritional requirements of redclaw for digestible protein (DP) and digestible energy (DE)
ii) assess the suitability of alternative feed ingredients
iii) develop a practical feeding standard for this species with optimised feeds and feeding regimes
Achieving these objectives will deliver:
• A detailed description of the requirements for DP and DE for redclaw throughout the growout period and under different environmental conditions. Determination of digestibility co-efficients of raw ingredients will allow compound diets to be formulated based on a digestible rather than crude basis resulting in more nutritionally efficient diets for redclaw. Improved cost efficiency in redclaw growout can then be achieved by feeding diets optimised for digestible nutrient content.
• A nutritional assessment of alternative feed ingredients such as legumes (e.g. soy, lupins) and their value in supporting redclaw production in pond culture. This will provide options for supplemental, cost effective, feeding by farmers as well as detailed compositional information necessary for formulation of compound diets
• A practical feed evaluation system for redclaw describing diet specifications and feeding regimes based on the requirements for DP and DE for this species throughout the growout phase. Feeding standards will be prescribed under a number of culture conditions (pond vs. laboratory) including varying environmental scenarios (e.g. temperature) to optimize feeding rates. A nutritionally optimised diet will promote more efficient growth rates while at the same time reducing environmental waste outputs.