Feeding Frequencies Of Heterobranchus Longifilis Fry And Fingerlings In Static Aerated Rearing System

Abstract

Two separate experiments were carried out to determine the suitable feeding frequencies for fry and fingerlings of H. longifilis. In the first experiment, H. longifilis fry of mean weight 0.59  0.02g, stocked at 10 fish/trough were fed rations of 44% crude protein at frequencies of two, four, six, eight and ten times daily for 42 days. The fry fed 4-times daily had the best growth among all frequencies. In the second experiment, H. longifilis fingerlings of mean weight 8.23 +- 0.22g stocked at 5fish/trough were fed rations of 45.36% crude protein at frequencies of two, three, four, five and six times daily for 56 days. Rearing was done in an aerated static system of 26.4 litres water capacity. The protein efficiency ratio was highest for fish fed 4 times and 2 times daily for the fry and fingerlings respectively. The specific growth rate (SGR) for the fry did not vary significantly (P ≥ 0.05) for all frequencies while there was significant variation (P ≤ 0.05) for the SGR of the fingerlings. There was significant variation (P ≤ 0.05) in food conversion ratio (FCR) in the two experiments. At the end of the feeding trials the fry fed 4 - times and the fingerlings fed 2 – times daily had optimal growth. This is an indication that H. longifilis fry should be fed 4 – times daily while the fingerlings 2 – times daily for optimal growth, good FCR, reduction of feed wastage and low operational cost.

Keywords: Feeding, Nutrition, Heterobranchus longifilis, Crude protein, growth rate

The Zoologist Vol. 5 2007: pp. 24-32