Aquatic product hydrolysates increase rearing performance in red seabream (Pagrus major), fed a low fish meal diet, in both controlled and stressed conditions: From growth to stress responses

• Published in: Aquaculture Vol. 576; p. 739830
• Main Authors: Herault, Mikael, Gunathilaka, Buddhi E., Fournier, Vincent, Le Bris, Hervé, Lee, Kyeong-Jun, Sadoul, Bastien
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-11-2023; Elsevier
• Subjects: Agricultural sciences; Chronic stress; Digestibility; Disease challenge; FM replacement; Growth performance; Life Sciences; Red seabream; Sciences and technics of fishery; Shrimp hydrolysate; Tilapia hydrolysate; Tilapia hydrolysate; Chronic stress; Disease challenge; FM replacement; Shrimp hydrolysate; Red seabream; Growth performance; Digestibility; Tilapia hydrolysateFM replacement
• ISSN: 0044-8486; 1873-5622
• DOI: 10.1016/j.aquaculture.2023.739830

Although aquaculture industry has made great efforts to reduce the levels of fish meal (FM) in aquaculture feeds, further efforts and investigations are still needed to increase aquaculture production, which has more than tripled in the last two decades. This study was implemented to Six replicate groups of fish (24.6 ± 0.1 g) were fed one of the experimental diets to apparent satiety twice daily for 15 weeks; half of them were subjected to a daily net chasing stress for 1 min in the morning, 1 h before feeding. At the end of the feeding trial, fish were challenged with Edwarselia tarda injection. LFM diet resulted in comparable growth and feed efficiency performance to HFM group. However, significant impairments were observed in apparent digestibility coefficients, condition factor, hematocrit and serum super oxide dismutase activity. Fish fed LFM showed much lower resistance to E. tarda challenge. Both TH and SH resulted in enhanced fish nutritional and health performance with significant improvements in growth performance, feed efficiencies, digestibility, serum non-specific immunity and gut morphometric parameters. Fish fed TH and SH also exhibited the highest survival after E. tarda challenge. Principal component analysis (PCA) showed significant differences between stress and dietary groups for dimension 1 (33.3% of the variability), which was mostly characterized by growth and health variables. SH and TH coordinates were significantly higher on dimension 1 compared to HFM and LFM ones. Daily repeated stress affected most of measured performance parameters of all dietary groups with very few interactions. The stressed fish groups fed TH or SH showed lower cortisol levels compared to those fed HFM and LFM (p < 0.01). Strong correlations were observed between feed efficiency and fish gut morphometrics as quantified by villi length, enterocyte height and goblet cell density. Dietary supplementation of aquatic protein hydrolysates such as TH and SH appeared to be essential for maintaining good fish performance when they were subjected to a daily husbandry stressor or to an infectious challenge.
•FM reduction may result in an impaired fish health status despite good growth•APH mitigate stress adverse effects•APH help to reduce FM and antibiotic uses