Growing Maggot for Animal Feed: My Little Experiment

[Henlus]

Very interesting. If I can replace even 30–40% of fish feed with maggots, it will be a huge relief.

Here’s what research and farm trials say:

Safe replacement level of commercial feeds with BSF maggots

20–30% replacement of commercial feed with BSF larvae (fresh or dried) works well — growth and survival are not affected.

Up to 40–50% replacement is sometimes possible if the larvae are well-processed (dried/defatted) and if fish get enough balanced amino acids.

Beyond 50% replacement, growth performance usually drops unless the diet is carefully reformulated, because maggots alone don’t provide the right balance of nutrients.

? How to apply this on-farm

Direct feeding method (supplemental)

Give commercial feed in the morning (for balance).

Feed dried maggots in the afternoon/evening (20–30% of the daily ration by weight).

Mixing method

Replace 20–30% of the daily feed ration with dried BSF meal (by weight).

Example: If you normally feed 10 kg/day commercial feed, give 7–8 kg commercial feed + 2–3 kg dried maggots.

Growth stage consideration

Fingerlings & juveniles: keep maggot inclusion lower (10–20%), since they need precise nutrition.

Grow-out/market size: can handle 30–40% replacement.

? Benefits

Cuts feed cost significantly.

Improves fish health (BSF larvae have antimicrobial lauric acid).

Provides high quality animal protein source.

[Henlus]

For replacing fish meal in poultry feed, i got this:

BSF maggots can replace fishmeal much more easily than soybean meal in poultry feed.
Here’s why:

Nutritional comparison (dry matter basis)
Fishmeal: 55–65% protein, good amino acid profile (esp. lysine, methionine), low fat (about 8–12%).

BSFL (maggots): 35–45% protein, high fat (25–35%), rich in lauric acid (which also helps fight gut pathogens).

Replacement potential

Studies show BSFL can replace 50–100% of fishmeal in poultry diets without reducing growth or egg production.

Some trials even found improved feed conversion ratio and immunity when BSFL replaced fishmeal.

Things to watch out for
Fat content – BSFL is much fattier than fishmeal, so the diet’s energy level must be balanced. Sometimes defatted BSFL meal is used for higher protein, lower fat.

Calcium/phosphorus balance – BSFL is rich in calcium (especially if grown on certain substrates). The mineral mix may need adjusting.

Processing – Drying and grinding maggots properly is important to avoid rancidity or microbial contamination.

[Henlus]

This is a gold mine if scaled up. Imagine replacing 50% of chicken feed with homegrown maggots. Feed is 70% of production cost. This can turn losses into profit.

Maggots cannot fully replace complete formulated feed for chickens. They are very rich in protein and fat, but low in energy, calcium, some vitamins, and certain amino acids (like methionine and lysine, depending on the substrate they’re raised on).
Broilers:
You can safely replace 10–30% of commercial feed with dried BSF larvae meal without negative effects on growth.
Some trials even report up to 40–50% replacement when diets are carefully balanced with extra energy and calcium.

Layers:
Replacement levels are usually 5–20% to avoid drops in egg production or shell quality.
Higher levels can affect egg size and yolk composition if not balanced.

Local/Free-range chickens:
They tolerate higher inclusion rates, sometimes up to 50% of protein sources, especially if they scavenge for extra energy.

Fresh vs. Dried Maggots
Fresh BSF larvae: fed as a protein-rich supplement (like a snack), but they’re mostly water.

Dried/processed BSF larvae: used in formulated rations, where replacement percentages are calculated on dry matter.