Information files | Queensland Crayfish Farmers Association

Feed Project Boosts Redclaw Crayfish Industry

(by John Stevenson, president QLD Crayfish Farmers Association, published in International Aquafeed, May 2017)

In 2001, with continuing encouragement and financial support from the Rural Industries Research and Development Corporation (RIRDC), the peak body of the redclaw crayfish farming industry – Queensland Crayfish Farmers Association (QCFA) – engaged James Cook University (JCU) to conduct a research project into feed and nutrition for redclaw titled “Boosting Redclaw Industry Productivity with Improved Feed and Nutrition Management”.

Farming redclaw crayfish is still a fledging industry in Northern Australia, having its inception in the early 1990s. This project is the second as part of an initiative by QCFA to conduct an ongoing research program to raise the level of professionalism of the industry and ensure there is a sound knowledge base for incoming farmers. The potential for success in farming redclaw is in no doubt, but knowledge is a necessary ingredient of success, and research projects such as this one and others supported by RIRDC are steps toward building a prosperous, thriving industry.

The five years, two-stage project considered practical aspects such as desirable pellet size, water stability and optimal feeding regime in Stage One. Stage two was an in-depth investigation into the actual nutritional requirements of redclaw, trialing alternative ingredients and developing a practical feeding standard specifically for redclaw. Information on this subject was practically non-existent, as no in depth study had ever previously been done into the specific nutritional requirements of redclaw crayfish. Consequently, there was little reliable information in the archives for the researchers to build upon.

The redclaw industry had considerable involvement in the project, continuing their close association with JCU. Contributing to financial support, supply of animals for trials, access to working farms for researchers to gather practical information and conduct trials and meeting for progress reports and discussion, were some of the ways the industry kept close ties with the progress of the project.

The project began at grass roots level utilising stable isotope technology to determine the actual nutritional requirements of redclaw and assessing the degree of benefits of past feeds and feeding practices. The project then moved on to running seven lengthy trials comparing animal acceptability and nutritional benefit of meat, fish and plant based diet; determining the effect of varying ratios of vitamin E and selenium; optimising protein and energy levels for growth, as well as considering the cost and environmental issues.

A plant based diet proved to be the most attractive to the redclaw, the cheapest to manufacture, resulted in the best growth rates and was the most environmentally friendly. This was considered a win of gigantic proportions by the industry. It was also found that the protein requirement for redclaw was some 30 percent greater than previously believed while still being quite low compared to other crustaceans.

Following the conclusion of the project by JCU and publication of the results in December 2015, the industry itself engaged in the task of optimising the actual composition of the feed to satisfy the project outcomes and optimise integrity and water stability of the pellets for an acceptable period. This work was done during 2016 with the assistance and co-operation of the Advanced Rural feed mill in North Queensland. The pellet produced contained a minimum amount of fines and held its shape in water for two to four hours. Further water stability improvements were made at some additional cost.

Four hours is a vast improvement on the performance previously attained. The proposed “Tracking Project” to monitor the behaviour of redclaw under water will tell us more about the feeding habits of redclaw as well as many other important, at this time unknown, behavioural traits. The farmers voted to adopt the second best option pending the availability of further knowledge of just how long the pellet needed to last and if the additional cost was justified.

The feed has been used by farmers during 2016 as an integral part of the implementation trials. Indeed, farmers are reporting up to 15 percent increase in production and an amazing level of animal acceptance and attractability.

The full project Final Report from JCU is available from RIRDC.

FEED TRIALS – RESULTS, IMPLICATIONS AND CONCLUSIONS
North Queensland Crayfish farmers Association – 2016

INTRODUCTION:

Following conclusion of the Feed and Nutrition Project in December 2015 by James Cook University, it became the responsibility of QCFA to do what was necessary to implement the results and facilitate how the industry could maximise the benefit of the research. The obvious answer was to deliver the new feed to the redclaw in the most beneficial way. This meant making a pellet that had good water stability and was physically sound while complying with the specified protein and energy requirement. Trials were conducted over a period of six months and the best decision made based on the results.

FORMULATION:

The formulae for the new feed allows for 26% protein for adult feed and 28% for juveniles as recommended by the JCU Feed and Nutrition research project. It also contains a binder to help water stability and a specific Crustacean Vitamin and Mineral Premix. The diet is vegetable based, containing no meat or seafood products, also as a result of the research project findings.

TRIAL DATA and RESULTS:

Cost implications of ingredient variations:

Replacement of 25% of wheat with Flour – + $60/t

Replacement of 50% of wheat with flour – +$120/t

Oil coating (used for energy in pig feed) +$9/t

Salvetti full fat soy 100% + $155/t

Mastercube binder + $5/t per 1kg binder added

All batches have been made to the 26% protein level recommended by JCU

Trial Results:

Batch 1 – 9/3/16 – 15 days after die change (est)

Supplied to Colin

5kg Mastercube added

Zero fines – swollen but intact after 3 hours – good stability

Batch 2 – 4/5/16 – 14 days after die change

Supplied to Klaus

3kg Mastercube added

Zero fines – slight disintegration after 2 hours – fair stability

Batch 3 – 4/5/16 – 14 days after die change

Supplied to NQCFA – Distributed to members

5kg Mastercube added

25% of wheat substituted with flour

1.3% fines – swollen but intact after 3 hours– good stability

Batch 4 – 14/6/16 – 27 days after die change

10kg alternative binder added without consultation

Oil coated

3.4% fines – disintegration in 30 minutes – failed stability trial

Alternative binder useless – batch destroyed

Batch 5 – 1/7/16 – 15 days after die change

Supplied to Beldans

100% Salvetti full fat soy

5k mastercube

18% fines – Disintegration started inside 1 hour – unacceptable

Batch 6 –1/7/16 – 15 days after die change

Supplied to Colin (bulk)

50% Salvetti full fat soy

5kg mastercube

6% fines – Disintegration began immediately – unacceptable

Batch 7 –1/7/16 – 15 days after die change

Supplied to Joe

100% USA soy

10kg mastercube

3% fines – Disintegration began after 1 hour – barely acceptable

Batch 8 – 14/7/16 – 28 days after die change

Supplied to Klaus

5k Mastercube

5.7% fines – moderate disintegration after 4 hours – barely acceptable

Batch 9 / 10 – 25/7/16 – 3 days after die change

Supplied to Mick and Bill Keast

Standard 5k Mastercube

1.3% fines – Swollen but intact after 2 hours – fair stability

Batch 11 – 8/10 – 2 days after die change

Shared

50% wheat substituted as flour

3.8% fines – excellent stability

Batch 12 – 8/10 – 2 days after die change

Shared

juvenile feed – 28% protein

`0.3% fines – fair stability

QCFA FEED IMPLEMENTATION TRIALS – February to July 2016

Days after new die

Immersion hours

Batch

Farmer

Date

Variations

Calendar

Week

% Fines

cost

Colin

9/3

Standard

1.7

SNB

MBS

MDS

750

Klaus

4/4

3k M’cub

1.6

SNB

MBS

MDS

740

4/4

25%Flr

1.3

SNB

MBS

MDS

810

Scrap

14/6

Alt bind

3.4

Oil coat

Beld.

1/7

100% full

MoD

905

Fat soy

Col

1/7

50% full

MDS

MoD

D/R

822

Fat soy

Joe

1/7

10kM’cu

MBS

MoD

D/R

774

Klaus

14/7

Standard

5.7

SNB

MBS

MDS

MoD

750

Mick

25/7

Standard

1.3

SNB

MBS

MDS

750

Bill K

28/7

Standard

1.5

SNB

MBS

MDS

750

8/10

50% Flr

3.8

SNB

878

8/10

Juvenile

0.3

SNB

MBS

MDS

770

TStk

A/Ru

Origonal

670

Gymp

MDS you very much

MoD

Standard Diet – 26% protein – 5kg Mastercube

Cost is ex-mill – 25kg QCFA bags – plus 4% levy + GST

LEDGEND:

SNB Swollen not broken

MBS Minor breaks with stick agitation

MDS Minor disintegration with stick agitation

MoD Moderate disintegration with stick agitation

D Completely disintegrated

R Rubble – trial terminated

DISCUSSION:

PELLET QUALITY:

Pellet quality was judged by the fines content and general condition of the feed. “Fines” are defined as particles that fell through a 3mm sieve.

The above results display a marked relationship in quality (% fines) to the number of days following a die change when ingredients are similar.

The results indicate the pellet quality problem lies mostly with the condition of the die, rather than the content of the pellets.

The results of physical damage deliberately inflicted on the pellets, indicates that the fines are not the result of pellet crumbling, but that they have never in fact been pelletised

Inquiries with the mill have found that the die routinely lasts around four weeks. The ‘days after die change’ figures have been split into calendar and week days to negate the effect of weekends and holidays

The integrity of batch 4 was compromised because the mill substituted an alternate binder for Mastercube without consultation. Batch 4 plays no part in the comparison. This batch was made right at the end of the die life and it is not known for sure whether the total unacceptably of this batch was because of the binder or the die condition or both.

Batches 5 and 6 were trials of using local Full Fat Soy meal in place of imported soy meal at midrange die life and were unacceptably high in fines

Batches 5 to 7 were made in a 24 hour period so their comparative results are not influenced by die life even though the percentage of fines varied widely, indicating that composition as well as die life are factors in pellet quality.

Batch 8 was made right at the end of the die life and certainly displays high fines percentage

Batches 9 and 10 were made immediately after a die change and have an acceptable level of fines. Batch 9 contained an unexplainable content of whole sorghum which caused the pellets containing it to break readily.

Batch 11 was made 2 days after die change and with flour substituted for 50% of the wheat content. The fines content was unexplainably high considering that Batch 12 was made the same day and showed excellent fines level.

WATER STABILITY:

Water stability was assessed by immersing pellets in a shallow dish of water and recording their condition at hourly intervals up to 4 hours. Pellets were moved around gently with a paddle pop stick at each assessment to simulate movement by grazing redclaw. Six levels of pellet condition were established:

Swollen not Broken (SNB) means the pellets absorbed water but did not lose their form.

Minor Breaks means that the pellets broke into 2 whole pieces

Minor Disintegration means that some particles were leaving the pellet

Moderate Disintegration means a significant number of particles were leaving the pellet.

Disintegrated means the feed was no longer in a pellet form

Rubble means that the feed had turned to mush and was no longer readily available to redclaw.

The water stability of batches 1, 2, 3, 9 and 10 were reasonably consistent. After 4 hours immersion, pellets were still in a form to be available to redclaw and withstood gentle movement with an implement. Batch 11 did show the best water stability.

Batch 3 was used as a control throughout the trials and showed consistent results. Interestingly, at the end of the 7 month trial period the stability of this control batch proved better than when first made

Batches 5, 6 and 7 were made on the same day with variations in in ingredients. Contrary to expectations, the Full Fat Soy Meal batches 5&6 displayed very poor water stability. Double the amount of Mastercube binder in batch 7 also yielded poor stability. It is hard not to consider some unknown factor influenced these results given that they were made together, but no evidence of anything to substantiate this was found. It can only be deduced that the die age was the common contributing factor.

Batch 8 was made at the limit of die life and predictably displayed less than ideal water stability.

Batches 9 and 10 were made with a new die. Batch 10 was a repeat of batch 9 due to its sorghum content. The pellets in batch 9 that did not contain sorghum were unaffected.

Batch 11 with 50% wheat content as flour was the best performing batch of the trial.

Batch 12 was the juvenile formulation with 28% protein. it show water stability charactistics the same as other standard batches

COST:

The bagged price of the “old” feed was $670 per tonne. The bagged price of the “new” feed in standard form is $750 per tonne. The additional cost is due to the increased protein percentage and binder. The bagged price of the batches trialled with 25% and 50% of the wheat content substituted as flour were $814 and $878 per tonne respectively. The juvenile feed price is $770 per tonne due to the higher protein level. In all cases, bagged feed is $40 per tonne dearer than bulk ex-mill. Prices are from Advanced Rural mill Tolga NQ.

The prices are plus 4% QCFA Research Levy plus GST

These prices are all within the guidelines set by farmers at an NQCFA meeting.

RECCOMENDATIONS:

It is strongly recommended that farmers enquire with the mill regarding the date of die changes when ordering feed. Results show that it is advisable the feed be made within a 10 working day period following die change.

The decision of which formulation will be adopted as the standard “Redclaw Feed”, has to be a balance of quality and cost. This is a farmer’s decision, not a researcher’s, and will be decided at an Association meeting.

CONCLUSIONS:

Die life is not the only governing factor in producing a pellet with acceptable physical properties and water stability. However it is the major contributing factor and can be managed.
After exhaustive trials with eleven combinations of ingredients, the formulation including 5kg Mastercube binder per tonne proved to be acceptable. The addition of 25 and 50 percent of the wheat content as flour to reduce the size of the particles in the mix did certainly improve the water stability but not the amount of fines in the product
NQCFA’s water stability and pellet quality trials with various ingredients and die life have resulted in a product that has qualities in these areas that we feel will be acceptable to the industry. Further improvement may be possible in the future in the light of new knowledge.
The cost as well as the quality has always been a consideration. Farmers agree that a feed of improved performance and quality justifies any reasonable additional cost. The results table show that the most expensive option was not the best and the cost of the new feed has been kept at an acceptable amount.
The pellets maintained their shape and integrity for a reasonable period, even though they swell and become “rubbery” soon after immersion in water. Previously it was planned to make the juvenile redclaw feed in crumble form to facilitate consumption by small animals. Owing to it becoming “rubbery” it is now believed that feed in standard pellet form would be suitable for juveniles.
Usage of juvenile feed will be small, as (a) small animals don’t eat much (b) it will only be fed for the first 3 months of growth and (c) will be mostly required only during the summer months. As the mill has a 1 tonne minimum, NQCFA will purchase a tonne which will be for sale at the October 2016 meeting as a service to members. It will be suggested to other branches that they consider adopting this system. Whether this practice is workable long term remains to be assessed.
On farm assessment of the new feed’s influence on redclaw growth will very likely not show concrete results for some months. The redclaw are showing a marked preference for the new feed over other baits when used in baited traps. Early indications are positive and indicate that the work of JCU will be of great benefit to the industry. Farmers will be asked for feedback at the May 2017 NQCFA meeting.
Many NQ farmers have been involved in this trial and have displayed patience and willingness to accept the not so successful batches as well as the successful ones as being part of achieving the best possible outcome. Our thanks to them all.
Throughout the trials, Advanced Rural have displayed an amazing level of co-operation and patience – especially considering the insignificant part redclaw feed plays in their business! Our thanks fellas.
At the NQCFA meeting on 8^th October 2016, the members considered the information in this report and voted in favour of adopting the “Standard” formulation as redclaw feed. While it was acknowledged that the substitution of percentages of flour for wheat did improve the water stability, given the uncertainty of just how long the pellets needed to remain intact, the additional cost was not justified. It was voiced that should further knowledge or developments come to hand from the proposed ‘Tracking Project’ or any other source, this decision could be revisited.

John Stevenson

President, QCFA

Article in “here’s 10 things to know from QFF” (Queensland Farmers’ Federation), published in September 2016

REDCLAW FARMING ON THE CUSP OF RESURGENCE

On the back of a 10 year research program funded by the Rural Industries Research and Development Corporation and guided by the establishment the industry’s “Operation Kickstart” – a planned program of industry promotion – the redclaw industry is set for a rebuilding phase. Hard lessons have been learnt from the 1990’s boom period, when many people launched themselves into redclaw farming without sufficient forethought, advice, experience, financial backing and knowledge.

New opportunities and knowledge from the results of the Selective Breeding Program, Feed and Nutrition Project and Survival Investigation have injected a series of boosts into the industry over the last five years.

The industry’s informative website – www.queenslandredclaw.org – and the book “Redclaw Farming – Getting Started” were launched in 2013 and a Conference and workshops across the state followed. These initiatives have attracted spirited interest from Queensland, interstate and overseas – sales of the book are vigorous and are indicative of a keen and continuing interest in the industry.

Current farmers, many of whom have been farming successfully since the inception of the industry, are enjoying the prosperity due to the results of research projects and are buoyed by the achievability of profitable sales opportunities. Demand for the product is strong and product quality is excellent. The mass of problems of the early years have been overcome with the acceptance of the fact that redclaw farming is a business like any other. It is not feasible to adopt a hobby style approach and still be successful and profitable.

At this stage all current farms are at a “family business” level, but a Scoping Analysis and Business Plan for large scale farms is in the works. An active State Association incorporating three Branch Associations has the future security and success on the industry firmly in its sights. Involvement with the Federal Government’s North Australia Plan and the Northern Gulf Management Group will result in the development of major farms in the not too distant future.

John Stevenson
President QCFA

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