Energy: protein ratio in the nutrition of peacock Bass (Cichla sp)

Author(s)

Ana Maria Barretto de Menezes Sampaio

• Document type: Master's Dissertation
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 1999-01-22
• Advisor: Jose Eurico Possebon Cyrino

Abstract

To evaluate the effect of energy to protein ratio in the performance and body composition of peacock Bass <i(>Cichla sp) 196 fingerlings of the species weaned to accept dry feed, with an average body weight of 10 g, were housed in 25 L cages, placed in 16, 500L-cement boxes, under a water reuse system inside a greenhouse. Water temperature was kept at 27,7°C through 300-W heaters. Fish were fed ad libitum with a dry diet twice a day for 65 days with four iso-caloric rations (3.500 kcal DE/kg), with increasing leveIs of crude protein - 41%,37%, 33% e 30%, establishing DE:CP ratios of 8, 9, 10 e 11 kcal DE/g CP, in a totally randomized design (n = 4). Before starting the experimental period, a group of fish was slaughtered and carcass contents of protein, fat, water and ash were determined. At the end of the experimental period, groups of fish from each treatment were slaughtered for comparative carcass composition analysis. The results were submitted to ANOVA by the use of SAS statistical package, using general linear model analysis at 5% probability leveI. The average values of the evaluated parameters were, respectively: (a) feed intake: 295,28a; 243,93b; 241,36 b; 225,96b g; (b) feed conversion: 1,2b; 1,22 b; 1,35ab; 1,52a; (c) g daily weight gain:: 0,31a; 0,26b; 0,23bc; 0,19c g; (d) final weight: ) 30,59a; 27,16ab; 24,96bc; 22,35c g; (e) protein productive value (PPV%): 33,14; 31,33; 29,08; 23,21 (f) protein efficiency ratio (PER): 2,0; 2,21; 2,21; 2,18; (g); gross energy retention (GER%): 27,01; 28,62; 30,38; 24,22. No statistical differences were observed between treatments with 8 and 9 DE:CP ratio in regard to the feed conversion and final weight. Daily weight gain and feed intake values were statistically different. Because of reduced sample size, data on PPV%, PER and GER%, were only submitted to graphical comparisons, which revealed a decreasing tendency for PPV%, and increasing tendency for GER% as DE:CP ratio increased. Results allow to infer that nutritional requirements of peacock bass can be met by diets containing between 8 an 9 kcal DE/g CP, or 37 to 41% CP and 3.500 kcal DE/kg of diet. (AU)