Asian Fisheries Society

Comparison of Five Different Practical Diets with Various Concentrations of Dietary Protein in Nursery Ponds: Survival and Growth of Indian MajorCarp Fry

Abstract:

The purpose of this study was to evaluate the existing and modified experimental diets for use in nursery ponds for feeding the Indian major carp fry. Fry (mean body weight 1.11 ± 0.06-1.18 ± 0.01 g) were stocked (@ 3.2 lacs ha-1) in nurseries in August and fed on one of the five formulated diets (Protein contents ranged between 28 to 35%) over a period of 40 days. Lowest survival, growth and SGR were observed in ponds (treatments 1 and 2) where the fry were fed on traditional diets. Studies have further revealed that survival and growth (weight and length) of the fry increased, while FCR decreased with each increase in the dietary protein, fat and grass energy contents. An increase in the inclusion levels of full fat processed soybean for obtaining high protein and energy, not only improved fry surrival and growth, but also diminished ammonia pollution in nurseries. An investigation on the effects of feeds on water quality parameters have revealed that nutrients (o-Po4, total kjeldhal nitrogen, No3-N), alkalinity and turbidity and all the productivity indicating parameters viz. chlorophyll ‘a’, net primary productivity, including plankton population, their species diversity increased with each increase in the dietary protein contents and thus highest values coincided with the highest survival and growth. An analysis of bottom sediment have revealed that nutreints (o-Po4 and No3-N), alkalinity and benthic population also followed a similar trend. Multivariate analysis (Prien et al. 1993) of the data also revealed a significant (P < 0.05) positive correlation of nutrients, NPP and plankton population with fry growth. These studies thus indicated that the traditional diets used by the farmers are nutritionally inadequate. Hence to obtain high survival and growth in high density stocking, farmers may have to feed the fry on supplementary diets containing high protein contents (< 35%) preferably of plant origin supplemented with micronutrients and amino acids.

Publication Date : 2004-06-01

Volume : 17

Issue : 2

Page : 121-134

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Date 2004/06/01
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