RESUMO
Effects of substitution of fish meal by processed chicken feather meal in diets based on broiler starting ration at two environmental temperatures for juvenile Tilapia nilotica were investigated. Juvenile Tilapia nilotica [ca. 4 g body weight] were kept for 3- weeks adaptation period, after which they were cultured at the rate of 14, 12, 14, and 11 fishes in aquaria I, II, III and IV, respectively. The prepared diets were fed at a rate of 3% of the fish biomass and offered twice daily throughout an experimental period of 12 weeks. The highest average final fish weight was recorded in fishes of aquarium I [12.14 g] followed by those in aquarium IV [10.57 g], aquarium II [6.9 g] and finally aquarium III [6.8 g]. The food conversion ratio amounted to 1.8, 4.98, 5.05 and 2.6 for fishes in aquaria I, II, III and IV, respectively. Values of protein efficiency ratio were 1.77, 0.66, 0.67 and 1.13 for the respective aquaria. Proximate chemical analysis of fishes was not consistent and did not reveal appreciable differences between aquaria