Effects of different levels of protein, energy and their interaction on growth factors of Indian shrimp (Fenneropenaeus indicus) of different sizes

Three experiments of 28 days duration were conducted in three size groups (<1g, 1-5g and 5-10g) of Indian white shrimp, Fenneropenaeus indicus, to evaluate the appropriate protein: energy (GE) ratios in their diets. A common ingredient mixture consisting of fish meal, shrimp meal, ground nut oil cake, cholesterol, lecithin, vitamins and minerals blended with chicken egg albumin, tapioca flour and cellulose (filler) to formulate nine feeds with protein levels of 35%, 40% and 45% and GE levels of 380, 420 and 460 kcal/100g at each level of protein (i.e:35:380, 35:420, 35:460; 40:380, 40:420, 40:460 and 45:380, 45:420 and 45:460). Nutritional responses in terms of weight gain (g/individual), RGR, FCR, FCE, PER and PPV indicated that the protein: GE combination of 45:460 to be best in samples of  £lg size. Since weight increases were progressive, without indicating an optimum in this group of animals, protein levels beyond 45% needs to be explored.  In the size group of 1-5g the protein: GE combination of 40:420 was found to be appropriate, indicating a decline in the requirement of protein and energy as growth progresses. In the size group of 5-10g, a further decline in the protein: GE combination was observed with the protein: GE combination of 35:380 performing the best among the levels tested. In this size group a protein level lower than 35% has to be investigated. The findings reported are discussed in the light of relevant reports.