The Best Alternative Feed Options for Catfish, An Objective Comparison Between Duckweeds and Maggots, Which 1 Comes on Top?

The ever-increasing cost of commercial catfish feed has led many farmers to seek alternative feed options for catfish. While this is a welcomed development, it is important that farmers truly comprehend the alternative feed options available for catfish, but more importantly, which ones offer better results for their efforts.

The rising cost of catfish feed has rendered catfish farming unprofitable for many farmers, thus the search for alternative feed options for catfish has seen a consistent rise.

This search is noble and understandable, after all, we all want to make good profits from our businesses, and this is where this article comes in handy.

We too have been in your shoes in years past on a quest for alternative feed options for our catfish farming businesses. Trying all the solutions the internet had to offer. Many of these solutions while theoretically good are practically impossible to sustain on a large scale.

Our goal is not to bastardize any particular alternative feed for catfish but rather present to you our experience in dealing with them, and to help you make informed decisions.

Alternative Feed for Catfish

A quick search on the web for alternative feed options for catfish would reveal the following to you.

• Poultry waste, abattoir waste, etc.
• Earthworm
• Azolla, duckweed, etc.
• Maggots from Black Soldier fly

For us at Farm Armelio, we quickly came to the realization that poultry offals, abattoir by-products, etc. are not a sustainable way to grow our catfish farm, after all, how many kilograms of these can we truly get a day?

For this reason, our experiment on alternative feed options for catfish production in Ghana did not include poultry waste or abattoir waste, we will be thrilled to know the results from those who have ever taken such a route for alternative feeding of catfish.

Our focus so far has been on the last two, Azolla and maggots, of which we can talk at length, but in order not to bore you with too many details, these are our experiences trying to use Azolla and maggots as an alternative feed for catfish production.

With everything new, obviously, there were challenges with using these alternative feeds for catfish production, however, it didn’t take us long to come to a quick realization that we have cut down the cost of production by half by using duckweeds and maggots, however, for a farm that hopes to sell minimum 20 tons of catfish a day, our goal was to compare and contrast and to determine which of these two provide the best returns for a farmer.

Using Azolla or Duckweeds as an Alternative Catfish Feed

Duckweeds were the first alternative feed for catfish that we used in production, our ponds at the time were 30ft by 60ft, and 9ft deep. This depth is of no advantage to growing duckweed, but just to give you a general idea of how many catfish we could stock.

A quick use of the catfish stock density calculator reveals that we could stock as much as 20,000 fingerlings per pond with no issues at all.

In order to truly grow duckweeds and have them available for the catfish all the time, we dedicated one of the ponds to growing the duckweeds.

It took a while to get the fertilization right, but after we got it, we had duckweeds growing and multiplying on a daily basis.

Note that at this point of production, we had severely underestimated our cash needs for feed and were basically down on cash for commercial catfish feed, we were relying entirely on duckweeds as an alternative feed source for the catfish.

We fed our catfish as many duckweeds as we possibly can, but still suffered weight loss amongst the fish.

While the fish enjoyed the duckweed, what many farmers fail to consider is the feed weight to body weight gain ratio for the feed being served.

For commercial catfish feed in Ghana, we have experienced as worse as 1.5kg of catfish feed to 1 kg body weight gain, and as best as 1.2kg to 1kg body weight gain.

So if our catfish are losing weight after feeding them several baskets of duckweed, could it be that the feed-weight conversion ratio of duckweeds is bad?

Here are the facts;

• Fresh duckweeds contain up to 92% water
• Crude protein levels of 43%

As a farmer, once you read that duckweed can give you crude protein levels compared to commercial fish feed, your excitement shoots through the roof, but the truth is hidden in the figures above.

Over 92% of the duckweed is water, which provides no nutritional value to the catfish. Keep this in mind as we proceed.

This means that the percentage of duckweeds that provide some benefits to your catfish when used as an alternative feed for catfish is barely 8%.

To put this into perspective, for every 100 kilograms of duckweed you harvest to serve your catfish, only 8 kilograms of them would provide some nutritional benefits to your fish. Of these 8 kilograms, only about 43% of them are crude protein.

This means for every 100kg of duckweed you harvest to feed your catfish, your catfish would only get 3.4kg of crude proteins.

These are hard-core facts, I do not make them up, the only contentions we can make from these figures are the percentage of protein in duckweeds, the research works are not consistent with the percentage of proteins, we have articles pointing as low as 35% to as high as 48%.

However, even if you use the highest percentage figure of 48% crude protein, 48% of 8% is barely 3.84% thus for every 100kg of duckweed you harvest, you only get 3.84 kg of crude protein.

These are the hard-core facts that are often missing in the discussion of the use of duckweeds or Azolla as an alternative feed option for catfish production.

If you are still reading this, I encourage you to be as independent a thinker as possible, do not just take my word for it, but do your research and the maths and let us know if we are wrong.

Catfish farmers have suffered enough at the hands of ill-explained literature, or little-understood materials, paraded by supposed experts with no real-world experience, causing many farmers to suffer losses.

Imagine a farm with 20,000 catfish, at a point, you might even be feeding them as much as 150kg worth of feed a day, how many kilograms of duckweed can you produce a day to match up?

Besides duckweed’s ability to clean the pond, in our experience, the use of duckweeds as an alternative feed for catfish has proven counterproductive, at best, we use duckweeds in the pond just to help filter out waste, and this led us to the use of maggots as an alternative feed option for catfish production.

Using Maggots as an Alternative Catfish Feed

Compared to duckweed, maggots do not require a dedicated pond to grow, now you heard maggots and I can immediately imagine the grown on your face, but fear not! the type of maggots we talking about is from the black soldier fly, an organism that does not eat in its insect stage and thus do not act as a vector for diseases.

Indeed, using inserts as a viable alternative to fish meal in feed production has since been researched and implemented, Volta Catch in Ghana, is one of the few companies that actively use inserts as a protein alternative to fish meal in commercial feed production.

What I am introducing you to, is not a charade, but a proven method used even in commercial production. Indeed, Black solder fly larvae have been experimented for human consumption in the production of milk for children in Indonesia.

The larvae (maggots) of the black soldier fly has a crude protein percentage of about 50% of dry body weight, Fat 26%, Calcium 7.56%, and an amino acid structure similar to fish meal. This has made the use of black soldier fly larvae (maggots) the number one choice in alternative feed for catfish.

However, BSF larvae come with their own challenges, with every statistical figure, there are always subtle nuances that need to be considered.

For instance, it is said that BSF larvae have over 50% crude proteins but this percentage is for dry body weight. BSF larvae have about 70% water, which means, for every 100kg of the larvae, 70kg is water, which you lose when you dry the larvae, of the remaining 30 kg, 50% is the crude protein, thus for every 100kg fresh BSF larvae you harvest, 15kg of it is the crude protein.

These calculations are crucial especially since we are looking for alternative feed options for catfish. The commercial feeds we buy do not contain water, when a feed is said to contain for example, 42% crude protein, you can be sure that for every 100kg of the said feed, 42kg of it should be the proteins.

Getting this understanding would aid us in better feed formulations, even when using alternative feed options for catfish.

Comparing Duckweeds to Black Soldier Fly Larvae (Maggots)

Each of these alternative feed options for catfish has its pros and cons, what we have discussed above is from our real-world experience, our goal isn’t to bastardize any of them, we just do not want to see other farmers suffer what we did.

If you have a very large pond (by large I mean large, cos even a 30ft by 60ft pond, could not sustain 1000 catfish) and can grow duckweeds in large quantities to meet demands, why not, by all means, go for it, but if space is an issue, and you want to produce in large quantities from a small space, BSF larvae (maggots) is the way to go.

In my experience though, the best use of duckweed is for supplemental feeding, but for alternative feed options for catfish, Black Soldier Fly larvae (maggots) come on top