Abstract
We evaluated the effects of various dietary blood meal levels on the growth performance and body composition of pirarucu (Araipama gigas) juveniles. Fish (8.5 ± 0.4 g) were stocked into 24 tanks and fed for 60 days with eight isoproteic diets, having 0% to 21% incorporation of blood meal. Fish increased weight by six to 15 times from their initial weight. The highest body weights (117–135 g), growth rates (4%–5% BW/day), and protein retentions (19%–20%) were observed in fish fed 0% to 6% blood meal. Feed intake increased from 2.9% to 4.4% BW/day with increasing blood meal level. Feed conversion ratio (FCR: 1.0–1.1) did not vary among groups fed 0% to 6% blood meal (P < 0.001). However, when fish were fed more than 6% blood meal, FCR (1.3–1.7) and protein retention (11.1–13.7) deteriorated sharply. Lipid (7.7–11.7%) and energy (18.7–21.2 kJ/g) content increased with increasing blood meal levels up to 9%.
Acknowledgments
We are thankful to Ms. Maria Inês Pereira, Mr. Rui Sant'Ana, Ms. Cydia Furtado, and Mr. Rondon for their valuable assistance during the feeding trial and chemical analyses.