Frequently asked questions (FAQs)

1. What is a typical, suitable proximate analysis for the diet for giant river prawn?

Below is a summary of dietary nutrient, including minerals and vitamins, requirements of giant river prawn

Two commercial feed suppliers include the following proximate analysis for their feeds:

*Brand name of feeds produced by commercial feed manufacturers
**HUFA= highly unsaturated fatty acid

2. What is a typical feed formulation for giant giant river prawn diets?

A typical pelleted feed would have the following composition:

3. What protein level and key amino acid levels should I use for prawn diets?

Setting optimum amino acid levels for incorporation into commercial diets of the giant giant river prawn is generally not necessary, as the natural pond productivity provides prawns with their requirements. Refer to question 1 for a typical protein level percent in the diet.

4. What plant protein sources and typical inclusion rates can I consider for prawn feeds?

Distillers dried grains and solubles (DDGS; 29 percent protein) are suitable for use in practical diets at up to 40 percent of the total diet formula. Fishmeal can be partially or totally replaced with soybean meal (<44 percent) and distillers' by-products. Other plant protein sources may include: moist pressed brewers' grains, corn silage, groundnut oil cake (<30 percent), sesame cake, copra cake, mustard oil cake (<15 percent) and coconut meal.

Plant products with lower protein levels that have been used in prawn diets include: rice bran, wheat flour (<35 percent), wheat gluten, wheat bran (<20 percent), barley (<35 percent), rice bran, broken rice (<9 percent), tapioca, maize (corn) meal (<25 percent), orange flesh, peeled sweet potatoes, cassava starch (<3 percent), frozen peeled bananas, alfalfa meal, turnip greens and carrot tops.

5. What typical animal by-product meals can I use in prawn feeds?

Good animal by-products as alternative protein sources are mussel meat meal, squid meal, shrimp meal, fishmeal and earthworm meal. Meat and bone meal and squilla meal can replace some fishmeal for the preparation of practical prawn diets.

6. What oils are suitable for inclusion for diets?

Most diets include some fish oil. Vegetable oils such as sunflower oil and soybean oil can be also included in the diet.

7. What vitamin and mineral mixture can I use in my pelleted feed for giant river prawn?

Giant river prawn requires 60mg of vitamin C/kg diet and 300 mg of vitamin E/kg diet for proper reproduction and offspring viability. Information on quantitative mineral requirement of giant river prawn is quite limited. In soft waters (<5 ppm calcium), prawn performance was good with a 3 percent Ca level. In harder waters (74 ppm calcium) 1.8 percent Ca level could improve performance.

8. What size of feed do I need at different stages, from first-feeding fry to onwards and how frequently should I feed them?

In many parts of the India, juvenile giant river prawn are fed with two different starter feeds as it is shown in the table below. These crumbles differ in size, but the nutrient content is the same. Starter feed 1 is fed for 45 days, thereafter starter feed 2 is used. It is however believed that there is no need to feed juvenile giant river prawn with two types of starter feed that differs in the size of the crumbles only. Pellets can be 3 mm (1/8”) in diameter. Other commercial feed suppliers of formulated pellets generally supply a wider range of pellet sizes.

*Brand name of feeds produced by commercial feed manufacturers

9. Is my farming intensity considered extensive, semi-intensive or intensive?

A stocking density of 8 500–17 000 per hectare is considered extensive production, while a density of 17 000–25 000 per hectare is considered semi-intensive. Intensive production at higher densities is not often practiced. In India, for example, grow out stocking densities range from 0.5–2.5 prawns per m² in polyculture and 1–5 per m² in monoculture, with a culture period of 6–8 months.

10. What yields are possible if I only apply fertilizers and do not use supplemental feeds?

Yields of around 300 kg/ha can be targeted in extensive farming systems that do not use supplemental feeds. Even in extensive systems, a variety of supplemental feeds such as mixture of rice bran, oil cake, wheat flour, and fish meal are usually used for prawn production.

11. How much dry feed do I use each day?

For the first month, post larvae are fed at 6–7 percent of body mass per day. The daily ration is then reduced to 4 percent. After two months, farmers apply feed for prawns as 2–2.5 percent of bodyweight daily. By about 20 g, the prawns are fed 1.5–2 percent of bodyweight daily. A typical commercial brand (Grobest) feed rate table is as follows:

12. What organic fertilizers can I use in my pond?

In general, prawn farmers use organic (mainly cow dung) and inorganic (urea and triple super phosphate [TSP]) fertilizers. Farmers with extensive farming systems may only use cow, as it is relatively cheap and available. Typical annual fertilization rates of cow dung are around 900 kg/ha. Up to 3 000 kg/ha can be applied. Other organic fertilizers such as chicken manure (600 kg/ha) can also be used.