Frequently asked questions (FAQs)
1. What is a typical, suitable proximate composition of a diet for Nile tilapia?
The diet of the Nile tilapia varies with fish size. Typical dietary proximate compositions are as follows:
Fish size | Fry (<10g) | Fingerling (10–30g) | Growout (>30g) | >300g | >300g |
Moisture | <10 | <10 | <10 | <10 | <10 |
Crude protein | 40–50 | 28–35 | 25–30 | 20–25 | >40 |
Crude lipid | 6–13 | 6–13 | 4–12 | 4–12 | >6 |
Crude fibre | <4 | <8 | <8 | <8 | <10 |
Ash | <16 | <16 | <16 | <16 | <16 |
Carbohydrate | >25 | >25 | >25 | >25 | >25 |
2. What is a typical feed formulation for a Nile tilapia diets?
Feed formulae (ingredient composition) and proximate composition of commonly used farm-made feed (as fed basis) for different life stages of Nile tilapia in semi-intensive farming system:
Ingredients/proximate composition | Life stages/size class | |
Ingredient composition (%) | Early fry | Fingerling | Grower (in cage) | Grower (in pond) |
| Cassava starch | 15 | 0 | 0 | 0 |
| Cassava meal | 0 | 23 | 23 | 22 |
| Coconut meal | 0 | 0 | 0 | 30 |
| Rice bran | 30 | 15 | 20 | 0 |
| Soybean meal | 0 | 30 | 25 | 25 |
| Fish meal | 47 | 25 | 25 | 20 |
| Fish oil | 5 | 4 | 4 | 0 |
| Dicalcium phosphate | 1 | 1 | 1 | 1 |
| Vitamin and mineral premix | 2 | 2 | 2 | 2 |
Proximate composition (%) | | | | |
| Dry matter | 8.03 | 9.00 | 9.00 | 9.01 |
| Crude protein | 30.00.00 | 31.00.00 | 30.00.00 | 29.09.00 |
| Crude lipid | 10.00 | 7.04 | 7.05 | 4.01 |
| Ash | 16.03 | 12.06 | 12.08 | 10.07 |
| Crude fibre | 3.08 | 4.02 | 4.04 | 6.00 |
| Carbohydrate | 31.06.00 | 35.08.00 | 36.03.00 | 40.02.00 |
| Gross energy (kcal/kg feed) | 2 800 | 2 700 | 2 700 | 2 500 |
| Cost (Baht/kg) | 15.01 | 11.03 | 10.07 | 8.05 |
| Cost (USD/kg) | 0.45 | 0.34 | 0.32 | 0.26 |
Source: Thongrod (2007)
Ingredient composition (%) | Pre-starter | Starter | Grower | Finisher |
Fish meal | 15.0 | 12.0 | 10.0 | 5.0 |
Fish oil | 4.0 | 3.0 | 3.0 | 2.0 |
Corn | 0.0 | 0.0 | 3.1 | 14.9 |
Rice bran | 0.0 | 24.6 | 35.0 | 35.0 |
Wheat bran | 10.0 | 10.0 | 10.0 | 10.0 |
Cassava | 6.7 | 10.0 | 10.0 | 10.0 |
Soybean meal | 62.4 | 38.5 | 27.3 | 21.1 |
Limestone | 0.6 | 0.7 | 0.7 | 0.8 |
Dicalcium phosphate | 1.1 | 1.0 | 0.7 | 1.0 |
Vitamin premix | 0.1 | 0.1 | 0.1 | 0.1 |
Mineral premix | 0.1 | 0.1 | 0.1 | 0.1 |
Proximate composition (%) | | | | |
Crude protein | 40 | 30 | 25 | 20 |
Crude lipid | 6 | 5 | 4 | 4 |
Crude fibre | 3.5 | 4.7 | 5.2 | 5.2 |
Cost (US$/tonne) | 300 | 250 | 220 | 2 |
Source: Creswell (2005)
3. What protein level should I use in a normal Nile tilapia diets?
Typical protein levels of pellet feeds for Nile tilapia are between 25 and 35 percent, but can be as high as 50 percent for fry and as low as 20 percent for finisher diets. A good general guideline could be as follows.
Protein requirements:
Life stage | Weight (g) | Requirement (%) |
First feeding larvae | | 45–50 |
Fry | 0.02–1.0 | 40 |
Fingerlings | 1.0–10.0 | 35–40 |
Juveniles | 10.0–25.0 | 30–35 |
Adults | 25–200 | 30–32 |
| >200 | 28–30 |
Broodstock | | 40–45 |
4. What plant protein sources and typical inclusion rates can I consider for Nile tilapia feeds?
Soybean oil cake (<62 percent inclusion), full fat soybean (<30 percent), groundnut meal/cake (peanut meal) (<36 percent), cotton seed oilcake (<19 percent typical, but some research shows <34 percent), maize germ oilcake (<11 percent), maize gluten meal (corn gluten meal) (<20 percent), rapeseed meal (<75 percent), sunflower seed meal (<48 percent), coconut meal (<30 percent), various legume seed meals, lupin seed meal, faba bean and sesame seed cake (<25 percent) have all been used in Nile tilapia diets. Growth performance, nutrient utilization and economic benefits are optimized with diets that have a mixture of plant protein sources. One example is heat processed oilseed meal mixtures replacing 50 percent of the fishmeal protein and containing equal proportions of soybean meal (SBM), cottonseed meal (CSM) and groundnut cake (GNC). This had 21 percent fishmeal, 10 percent soybean meal, 11 percent cottonseed meal, and 12 percent groundnut cake. In general, DL-Methionine added to the diet formulation improves growth rates at higher plant protein inclusion levels.
Copra oilcake, wheat bran, wheat grain, sorghum, barley, cacao husks and palm kernel contain lower protein levels of under 20 percent and are considered more as a carbohydrate source.
5. What oils are suitable for inclusion for Nile tilapia diets?
Fish oil, soybean oil, groundnut oil, linseed oil (flax seed), sunflower oil, maize (corn) oil and coconut oil are typically included in Nile tilapia diets.
6. What antioxidants can I use in my pelleted feed?
Commonly used antioxidants included in aquaculture feeds are BHA (Butylated hydroxyanisole) at 200 ppm, BHT (Butylated hydroxytoluene) at 200 ppm or Ethoxyquin (1,2 dihydro-6-ethoxy-2,2,4- trimethy quinoline) at 150 ppm.
7. What size of feed do I need for the different sizes of fish from first-feeding fry onwards and how frequently should I feed my fish?
Typical feed sizes, feeding rates and feeding frequency are as follows:
Fish size (g) | Feed type | Feed size | Feeding rate | Feeding frequency |
| | (mm) | (% body weight) | (no./day) |
0–1 | Powder/crumble | 0.2–1 | 30–10 | 8 to satiation |
1–5 | Crumble | 1–1.5 | 10–6 | 5–6 |
5–20 | Extruded, floating | 1.5–2 | 6–4 | 4 |
20–100 | Extruded, floating | 2 | 4–3 | 3 |
100–250 | Extruded, floating | 3 | 3–2 | 2 |
>250 | Extruded, floating | 4 | 2–1.5 | 2 |
This guideline should only be followed if water temperature is not too high (<350C) and dissolved oxygen (DO) level is above 5 mg/l. If temperature goes up and dissolved oxygen (DO) level is below 5 mg/l, feeding frequency should be increased with corresponding decrease in feeding rate. You should carefully monitor feeding behaviour and adjust the feeding rate (i.e., amount of feed) accordingly.
8. Is my farming intensity considered extensive, semi-intensive or intensive?
Semi-intensive tilapia farming is considered to be at densities below 20 000 fish per hectare until harvest, while intensive farming is for densities over 20 000 fish per hectare. Taking fish size into account, the following would be considered semi-intensive farming:
Life stage | Fish size (g) | Stocking density (no./ha) |
Early fry | 0–1 | 10 000–30 000 |
Fry | 1–5 |
Fingerling | 5–20 |
Juvenile | 20–100 | <10 000 |
Grower | >100 |
Broodstock | 150–300 |
Extensive farming in earthen ponds or natural water bodies uses low stocking densities, no feeding and tilapia production levels depend on the natural productivity of the ponds. Typical yields are below one tonne per ha (about 2 000 fish per hectare). Semi-intensive systems in earthen ponds use fertilisation to boost the natural productivity of the pond and supplemental feeding. Supplemental aeration is done in some cases. Semi-intensive yields can be as high as 5 tonnes per ha per crop. Intensive farming systems include ponds (up to 17 tonnes/ha), circular tanks and raceways. Yields can be as high as 100 tonnes per ha per crop in tank and raceway systems.
9. What yields are possible if I only apply fertilizers and do not use any supplemental feeds?
In general, tilapias can efficiently utilize natural food and yields of 3 000 kg per hectare can be sustained in well-fertilized ponds without any supplemental feed. This feeding strategy depends on the application of inorganic and/or organic fertilizers to stimulate the production of live food organisms and plants in the culture system and is typical of extensive and semi-intensive tilapia farming systems.
10. What organic fertilizers can I use in my pond?
Practically, any organic material can be used as a fertilizer. Look for what animal manures are locally available and are cheap. Poultry, pig and duck manures have relatively high phosphate and nitrogen contents and are good organic fertilizers. Make sure the manure has not been sprayed with insecticides. Detailed information regarding nutritional requirements is provided in question 1. On the other hand, specific information with regard to organic fertilizers is available in the main text.