Comparative study on dietary protein requirements for juvenile and pre‐adult gibel carp (Carassius auratus gibelio var. CAS III). (29th April 2016)

• Record Type: Journal Article
• Authors: Ye, W.; Han, D.; Zhu, X.; Yang, Y.; Jin, J.; Xie, S.
• Is Part Of: Aquaculture nutrition. Volume 23:Number 4(2017:Aug.)
• Page Start: 755
• Page End: 765
• Publication Date: 2016-04-29
• Subjects: Carassius auratus gibelio -- different body sizes -- gibel carp -- protein requirement; Aquaculture -- Periodicals; Aquatic animals -- Feeding and feeds -- Periodicals; Fishes -- Feeding and feeds -- Periodicals; 639.3
• DOI: 10.1111/anu.12442
• Languages: English
• ISSNs: 1353-5773

Abstract

Abstract: Two 8‐week growth trials were conducted in indoor recirculation system to evaluate the protein requirements for juvenile (3.70 ± 0.20 g) and pre‐adult (85.2 ± 0.70 g) gibel carp, Carassius auratus gibelio var. CAS III. Six isoenergetic diets were formulated for each trial using fish meal and casein as protein sources, and protein level was 250–450 g kg −1 in Trial 1 and 200–450 g kg −1 in Trial 2. With the increasing dietary protein, feeding rate (FR) and feed conversion ratio (FCR) significantly decreased ( P < 0.05). Weight gain (WG) increased first and then reached a plateau in 330–450 g kg −1 in Trial 1 ( P > 0.05), while decreased after the maximum value in 350 g kg −1 in Trial 2 ( P < 0.05). Productive protein values (PPVs) were lower in 370–450 g kg −1 in Trial 1 and 400–450 g kg −1 in Trial 2 ( P < 0.05). Increasing dietary protein level increased protein content and decreased lipid content in whole fish body and white muscle ( P < 0.05). Apparent digestibility coefficient of dry matters (ADCd ) decreased, while apparent digestibility coefficient of protein (ADCp ) increased in 370–450 g kg −1 in Trial 1 and 250–450 g kg −1 in Trial 2 ( P < 0.05). Trypsin activity significantly increased in 370–450 g kg −1 in Trial 1 ( P < 0.05) and was not affected in Trial 2 ( P > 0.05). Hepatic alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities in both trials increased when dietary protein was above 400 g kg −1 ( P < 0.05). Based on quadratic regression of WG, it was estimated that dietary protein requirement for maximum growth was 414 g kg −1 (digestible protein of 376 g kg −1 ) and 365 g kg −1 (digestible protein of 324 g kg −1 ) for juvenile (3.70 g) and pre‐adult gibel carp (85.2 g).