Frequently asked questions (FAQs)
1. What is a typical, suitable proximate analysis for the diet for Indian white prawn?
Proximate composition (%) | Larval | Post larval | Starter | Grower | Finisher | Broodstock |
Moisture | <11 | <11 | <12 | <12 | <12 | <10 |
Crude protein | 45 | 45 | 40 | 38 | 36 | 38 |
Crude lipid | 10 | 10 | 7 | 7 | 6 | 8 |
Crude fibre | <3 | <3 | <4 | <4 | <5 | <5 |
Carbohydrate | 10-15 | 10-15 | 10-15 | 15-25 | 20-30 | 15-25 |
Energy (Kcal/100g feed) | 340-400 | 340-400 | 320-400 | 320-400 | 300-400 | 300-400 |
Ash | <14 | <14 | <14 | <16 | <16 | <16 |
Phosphorus | | 1-1.5 | 1-1.5 | 1-1.5 | 1-1.5 | 1-1.5 |
2. What is a typical feed formulation for Indian white prawn diets?
Ingredients | Diet 1 | Diet 2 | Diet 3 | Diet 4 | Diet 5 | Diet 6 |
Fishmeal | 22-35% | 26.3 | 43.33b | | | 28 |
Wheat flour | 12-15% | 27.2 | 29.3 | 21.5 | 21.5 | 10 |
Soybean oil cake | 25-33% | 30 | 15.4 | 5 | 5 | 15 |
Squid oil | 1-5% | | | | | |
Brewer's yeast | | 5 | | | | |
Squid liver powder | 7-10% | | | | | |
Squid meal | 7-10% | | | 0 | 1.5 | |
Shrimp meal | 10-15% | | | | | |
Fish oil | | 2 | | | | |
Cod liver oil | | | | 1.75 | 1.75 | |
Fish solubles (dehydrated) | | | | 20 | 18.4 | |
Shrimp head meal | 2-5% | | | 13 | 13 | |
Shrimp shell meal | 9-10% | | | | | 25 |
Wheat gluten | | 2.5 | | | | |
Yellow corn | | | 6.6 | | | |
Rice bran | | | | | | 10 |
Groundnut oil cake | | | | | | 8 |
Lactic yeast | | | | 6 | 6 | |
Blood meal | | | | 2 | 2 | |
Wheat gluten | | | | 15 | 15 | |
Soy lecithin (crude) | | 2 | | 1.75 | 1.75 | |
Cholesterol | | 0.2a | | | | |
Palm oil | | | 2.6 | | | |
Potato starch | | | | 3 | 3 | |
CaCO3 | | | | 0.5 | 0.5 | |
NaH2PO4 | | | | 3.5 | 3.5 | |
Mono calcium phosphate | | 2 | | | | |
Vitamin & mineral premix | | 0.4 | 2.72 | | | 2 |
3. What size of feed do I need for the different sizes of shrimp from post-larvae onwards?
A good commercial feed manufacturer/supplier will include this information on the feed bag.
Start with the feed supplier’s guideline until you develop your experience with feed and shrimp species. A typical specification is as follows:
Shrimp size (g) | Feed type | Feed shape | Feed size (mm) | Feeding rate (% of biomass per day) | Feeding frequency (no./ per day) |
PL25-1 g | Starter 1 | Crumble | 0.5-0.9 | 13-9 | 1-2 |
1–2 g | Starter 2 | Crumble | 0.9-1.2 | 9-6 | 2-4 |
2–4 g | Starter 3 | Crumble | 1.2-1.8 | 6-4 | 4 |
3–7 g | Grower 4 | Pellet | 1.8 x 2-3 | 5-3.5 | 4 |
6–15 g | Grower 5 | Pellet | 2.0 x 3-4 | 3.5-2.5 | 4 |
Above 12 g | Finisher 6 | Pellet | 2.2 x 3-5 | 2.5-1.9 | 4-5 |
4. When should I start using feeding trays in the pond?
Begin using feed trays as early as possible. At first, use the feeding tray to look at the condition and quality of the post-larvae and get an idea of the survival and growth. After stocking, you need to keep only one or two trays in the pond for this purpose. Trays should be placed at least 30 centimetres deep in the water. From about 5 g of shrimp weight, feed trays become effective indicators of feed consumption, so four or more trays per hectare should be used.
5. How many times should I feed my shrimp per day?
Initially, when the shrimp are small and the feed quantity is minimal; two feeds per day will suffice. After about 30 days of stocking, this should be increased to about 4 or 5 feeds per day. Feeding frequency should be increased to the highest practical number. The feeding ration should be more during night than day. Use at least 2 trays per ha of pond water surface for semi-intensive ponds and six trays per hectare for intensive ponds. More detailed information is provided in question.
6. Why do I still get a high FCR even though I am using a well known and widely used feed brand?
Feed quality, feed freshness, feeding strategy, shrimp health, stocking density, size of shrimp at harvest and pond management all interact to determine the final FCR achieved, it is multi factorial growth parameter. Good feed management is as important as feed quality and needs careful attention to reduce feed wastage.
7. How do I practically apply feeding from my feeding tray records?
Many factors impact on this basic guideline. Shrimp will eat more just after sunset and at night, but will eat less if dissolved oxygen levels are low.
Feeding tray record as % feed on tray after 2 hours | Feed adjustment |
0 | Feed program (full feed or optimal level) or increase 10 to 25% |
<5 | Feed program (full feed level) |
5-10 | Previous feed amount x 0.90 |
10-25 | Previous feed amount x 0.50 |
8. How do I add cholesterol to the pelleted diet?
- Pure cholesterol has a high melting point and is usually supplied as a fine powder. It is added to the mixer after all other premixes are added.
- Lanolin containing 33 percent cholesterol can be heat-melted and mixed with the fish oil and lecithin and then added to the pellet mixture.
- Products like squid meal and fishmeal contain cholesterol that should be taken into account when estimating the dietary cholesterol level (0.33 percent for optimum growth). Research has shown that dietary protein and lipid sources affect cholesterol concentrations in shrimp.
9. Why is fishmeal included in all shrimp diets even though it is an expensive feed ingredient?
- Fishmeal is palatable to shrimp compared to all other animal and plant proteins.
- The essential amino acid profile suits the dietary requirements of shrimp and the protein from fishmeal can be easily digested.
- Fishmeal is a commodity that is used in all animal feeds and so is available in most countries.
- Fishmeal is mostly made from marine fish sources that have an oil content that provides important fatty acids needed in shrimp diet.
10. What plant protein sources and typical inclusion rates can I consider for white prawn feed?
Soybean meal (<30 percent), soybean concentrate (<30 percent), canola meal, canola concentrate (Brassica sp.) (<15 percent), pea meal (Pisum sativum) (<30 percent), lupin seed meal (Lupinus albus, L. angustifolius) (<17 percent), corn gluten meal (<7 percent) and wheat gluten meal (<8 percent, limited by cost before nutritional factors), sunflower seed meal, cottonseed meal (<9 percent). Note that these are general guidelines. Soybean meal has been used at up to 58 percent inclusion in well formulated research diets for Pacific white shrimp/whiteleg shrimp (Penaeus vannamei). The dietary amino acid balance is the major limitation in the increased use of plant based proteins in shrimp feed. The development of methionine analogues may meet methionine requirements in shrimp, allowing increased use of plant protein sources.
11. What is methionine analogue and how does it differ from methionine?
The amino acid balance in feed is the major limitation in the increased use of plant based proteins in shrimp feed. A methionine analogue is effective in meeting methionine requirements in shrimp. Powdered or dl-methionine, a 99 percent purity, feed-grade form is widely used in feed concentrate and premix production. Methionine analogues are other chemical sources of methionine activity. They generally have lower activity and this activity varies according to the analogue type and the target species. A liquid source of methionine (called Methionine Hydroxyl Analogue {MHA}, HMB, liquid methionine), has up to 88 percent methionine activity. MHA with calcium (MHA-Ca) is another source of methionine with up to 84 percent activity. With applied research into the suitability of these cheaper methionine sources for different species they are being more commonly used.
12. What typical animal by-product meals can I use in white prawn feeds?
Some fishery by-products other than fishmeal include squid meal, squid liver meal, crab meal, shrimp meal and krill meal. Some animal by-products include poultry by-product meal and hydrolyzed feather meal. Poultry by-product meal can potentially replace up to 67 percent of fish meal in well balanced diets. Feather meal with amino acid supplementation could potentially replace up to 33.3 percent of fish meal, based on recent research. Products like blood meal and whey products are not generally used in shrimp diets.
13. Is my farming intensity considered extensive, semi-intensive or intensive?
Shrimp growout comparison |
| Extensive | Semi-intensive | Intensive |
Stocking density (shrimp/m2) | 1-10 | 10-30 | >30 |
Pond size (hectare) | 5-20 | 1-10 | <0.5-2 |
Aeration (HP/ha) | None | None-2.5 | >2.5 |
Production (kg/ha/crop) | 100-1 000 | 1 000-2 000 | >3 000 |
HP = Horse power
14. What oils are suitable for inclusion for white prawn diets?
Sunflower oil, peanut oil, soybean oil, palm oil and marine fish oil (sardine, cod liver) are all suitable in terms of their dietary value for juvenile white prawn as long as soy lecithin is included in the diet.