World Aquaculture Society Meetings

PROTEIN AND ENERGY DIGESTIBILITY AND AMINO ACIDS AVAILABILITY OF FEATHER MEAL SUBMITED TO DIFFERENT PROCESSING TIME IN EXTRUDED DIETS FOR NILE TILAPIA

Tadeu Orlandi Xavier*, Mariana Michelato, Luiz Vitor Oliveira Vidal, Lorena Batista de Moura, Valéria Rossetto Barrivera Furuya and Wilson Massamitu Furuya
 
Programa de Pós-graduação em Zootecnia
Universidade Estadual de Maringá, Paraná, Brazil
*tadeu_zoo@yahoo.com.br
 

The Nile tilapia is one the freshwater species whose farming is rapidly growing in Brazil, where culture have been expanded from traditional earth pond to intensive net cages culture. However, there is limited information regarding nutrient digestibility and amino acid availability from feather meal for Nile tilapia. The objective of this study was to determine the apparent digestibility coefficients of protein and energy and amino acids availability of feather meal submitted to different processing time.

Nile tilapia (n=150; 24.5 ± 3 g initial weight) were stocked into five 250-L fiberglass aquaria at 30 fish per aquarium. A reference practical extruded diet (18.4 MJ kg-1 of gross energy) and isoproteic (273.2 g kg-1 of crude protein; as feed basis) was elaborated. Fish were hand fed until apparent satiation five times a day, seven days a week. Water temperature, dissolved oxygen and pH were measured weekly from each aquarium. To determine the apparent digestibility coefficients of energy and protein and apparent availability coefficients of essential and non-essential amino acids of feather meal a reference diet and eight test diets composed of 70% of the reference diet and 30% of the test ingredient were elaborated. All diets were processed in single screen extruder. The feather meal tested was processed under 3.5 kg/cm³ pressure and submitted to 10, 30 or 40 minutes of hydrolysis. Triplicate aquaria of fish were fed to their respective diet for seven days prior to collection of feces by modified Guelph system. All data were subjected to one-way analysis of variance (ANOVA) and Tukey's multiple range test was used to compare differences between the mean values at p < 0.05. It was concluded that 30 min of processing time is adequate to maximize nutritive value of feather meal for Nile tilapia.




Copyright © 2001-2019 World Aquaculture Society All Rights Reserved.