Summary

The aim of this project is to develop a redclaw feed that will maximise growth without sacrificing animal health, and to develop a feeding regime that provides the optimum amount of feed to the animals while conserving the farmer’s time. This project will compliment and enhance the results of the current RIRDC funded Redclaw Selective Breeding Program.

Prior feed related research projects have mainly concentrated on comparison of commercially available feeds, although some have investigated specific areas such as protein level for a particular sized animal. However, other major areas such as lipids, vitamin and mineral requirements, ontogenetic changes in protein requirements, water stability of feed, optimal pellet size range, and feeding regime have been left largely unstudied. A holistic approach is required to optimize nutrition and feeding strategies for redclaw

The redclaw industry is in dire need of information regarding the optimum feed formula and pellet size for redclaw as they grow from hatchlings to maturity. What restriction has been imposed on best possible growth rates by a “one size suits all” approach? It is believed redclaw gain much from natural food that grows on pond structures and also from living organisms in the water column – how much does this contribute to their nutritional requirements? Is it possible to feed a variety of locally available products that will supplement a specific pelletised food to combat the ever rising cost of freight?

This far reaching project will be designed to answer these questions and many others.

Program

New and Emerging Animal Industries

Research Organisation

James Cook University

Objective Summary

1. New Formulated feeds development: Little or no consideration has been given in past trials to show whether any currently available feeds are ideal, or to developing a formulated feed that addresses specific nutritional requirements of redclaw. It is also well known that redclaw rely heavily on natural food available in a pond environment. This project will develop a feed that is complimentary rather than competitive with such natural food. Freight cost will be considered.
2. Ontogenetic changes on nutrition requirements and size of feed: Currently, commercially redclaw feed is only available in one size. It is well known that as animals grow, their nutrition requirements as well as preferred size of diet vary. Attention will therefore be given to the different nutritional needs of redclaw as they grow from Stage Three Juveniles to adulthood, and an ideal pellet size and formulae will be determined for each stage.
3. Feed underwater stability: The underwater durability of redclaw pellets is an issue, as feeding is not instantaneous as is the case with fish. The water stability of many currently available pellets is measured in minutes and this impacts on their availability and nutritional value to redclaw. It also impacts negatively on water quality. Different manufacturing methods will be trialed to compare the resulting diet’s underwater stability.
4. Optimal feeding regime: The ultimate feeding regime will be developed to maximize the feed intake of the animal. Knowledge gained from the Tracking Project –the subject of a separate funding application – will supplement this work and allow a precise, dedicated and economical feeding regime to be developed.