Growing uniform-sized fish will boost farmer’s profits

One of the tilapia farmers’ biggest complaints is the lack of uniformity in harvest-sized fish, which reduces their profitability.

This is very understandable given that the Indonesian tilapia fingerling business model is focused on quantity rather than quality with hatcheries selling huge numbers of fry for very low prices.

But why does this affect uniformity? 

In any given batch of mono-sex fry that has been sex-reversed through hormone treatment approximately 10-20% are still female.  Females initially grow as fast, if not faster, than the males until they reach 40-80 grams, but their growth slows down as they put all their energy into reproduction rather than growth.   Of the male fingerlings, around 20% will be slow growers that consume a lot of feed but grow very slowly; and a further 5-10% are very fast growers and are oversized at harvest time.  That means that approximately 35-45% of mono-sex fingerlings will not make the required harvest grade.

Commercial hatcheries typically give newly hatched fry hormone sex reversal treatment until they reach 21-24 days.  The hatchery then grades the fingerlings for the first time when they are 25-30 days selling all fingerlings within 2-3 cm.  The slow growers that haven’t reached the size goal are removed, added to the next batch, and given a few extra days to grow before they are sold.  This practice ensures that the hatchery sells the maximum number of fingerlings, but the farmer buys up to 30-40% of fingerlings that won’t make the target harvest weight significantly reducing the farmers’ profitability.

Is it possible to produce uniform-sized fish?

It will never be possible to produce a uniform batch of tilapia fish with 10-20% from hormone sex reversal.  When the fingerlings are very young, females tend to grow faster than males, meaning grading in the first couple of months is ineffective at removing females.  The only effective way to remove female tilapia is through manual sorting when the fish are 20-50 grams which is time-consuming and places unnecessary stress on the fish.

However, it is absolutely possible to produce a uniform batch of mono-sex male fish, but it requires regular grading until the tilapia fry reaches 3-5 grams as well as culling the slow growers that will never make the tilapia farmer money as well as the super-fast growers that are carnivorous at an early age and eat other fingerlings.

Indo Aqua Sukses has placed ‘High-Quality Uniform Growing Tilapia’ at the heart of its operation.  First of all, 98% of Indo Aqua Sukses NMT are naturally male without using hormones so farmers do not have to worry about females distorting their batch uniformity.  Secondly, we grade our fry four times during the first three weeks which no other commercial hatchery is able to do as their fry is undergoing hormone sex reversal treatment.  The first grading takes place when the eggs are harvested, with eggs graded into four development stages ensuring the eggs hatch around the same time.  This is critical as Stage 1 eggs hatch about 8-10 days after Stage 4 eggs.  We then grade a further three times before the fry reaches 0.2 grams on Day 22.  This means the farmer just needs to grade on Day 30 (0.5 grams) and Day 47 (3 grams), thereafter the fingerlings will go on to grow at a uniform rate.

Is it worth paying more for a uniform batch of fingerlings?

Buying cheap tilapia fingerlings is a false economy.  A cheap fingerling may only cost you IDR50 but over the next six months, you will spend IDR3,200 on feed giving a total cost of IDR3,250.  But slow growers will only grow to around 150 grams in six months which means that its selling price is just IDR3,750 (based on IDR25,000 per kg). The farmer makes just IDR500 on a slow-growing fish, and that is excluding other expenses.  With around 35% of a batch either female or slow growers, it is not surprising tilapia farmers complain they don’t make much money.

However, spending more buying quality mono-sex tilapia fingerlings that will grow at a uniform rate will more than pay for itself.  This time the total cost of producing a six-month fish is IDR4,200 which includes IDR4,000 feed and IDR200 fingerling cost, but at 300 grams the farmer will receive IDR7,500 so will end up making IDR3,300 per fish.

For more information, please contact us.