Chonnakan Chitmanat, Thipsukhon Pimpimol, Masatoshi Matsumura, and Niwuth Whangchai

pp. 83 - 89

Abstract

This study was designed to examine the effects of green tea extract (GTE) additive feeds on the growth
performance in the giant freshwater prawn. Two separate trials were determined by using two different
stages of prawn for initial stocking, one was the small post larva (PL10), the other was 5.6 g prawn. A Completely Randomized Design was applied in this study. The small post larva (PL10) were raised in cement
tanks(1x1.5 m²). Three treatments with three replications each were performed applied as following: treatment 1 (control) was the commercial pellet feed; treatment 2 and 3 were feeds with 1% and 2% green tea
extract, respectively. This assay was run for 8 weeks. The prawns were randomly selected for weight determination every week. The result showed there was no significant difference in the specific growth rate and survival (P > 0.05) but the feed conversion ratio was reduced in prawn fed with green tea extracts (P < 0.05).
The feed conversion ratios in treatments 1, 2 and 3 were 4.0±0.1, 3.0±0.2 and 2.3±0.2 respectively. The second
experiment using the bigger prawn (5.6 initial weight) were conducted in 2x5 m² pens located in the earthen
ponds with 10 prawns/ m² stocking density. Two treatments were performed. Treatment 1 was control (commercial pellet feed) while treatment 2 was pellet feed with 1% green tea extract. This feed study was conducted for 75 days with random for weight checks every two weeks. The results showed there was a significant difference in growth rate (P<0.05) but there was not difference in survival rate, and feed conversion ratio
(P > 0.05). Therefore, green tea extract has potential as growth enhancer in giant freshwater prawn culture.