Dietary supplementation of astaxanthin krill oil enhances the growth performance of juvenile Litopenaeus vannamei raised intensively in enclosed and exposed tank systems under salinity stress

• Published in: Journal of applied aquaculture 2021-10, Vol.33 (4), p.344-359
• Main Authors: Rufino, Lucas Alves, Pinheiro, Simone Sales, Burri, Lena, Nunes, Alberto J. P.
• Format: Article
• Language: English
• Subjects: Air; Animals; Astaxanthin; Body weight; Colour; Conversion ratio; Diet; Exposure; Feed additives; Feed conversion; Feeds; Food conversion; Hypersalinity; Individual rearing; Juveniles; Krill; krill oil; Litopenaeus vannamei; Marine crustaceans; Oil; Physical growth; Salinity; Salinity effects; shrimp; Soybean oil; Soybeans; Survival; Tanks; Weekly; Yields
• ISSN: 1045-4438; 1545-0805
• DOI: 10.1080/10454438.2020.1760165

This work evaluated if dietary supplementation of astaxanthin krill oil with or without soybean oil to a grower shrimp feed enhances the growth performance of L. vannamei farmed under salinity stress. Shrimp of 1.08 ± 0.11 g body weight (BW) were reared for 74 days under 135 animals/m 2 in 50 1-m 3 outdoor tanks. Half of the tanks were operated enclosed by a milky-colored sheet and the remaining ones were fully exposed to sunlight and rain. Shrimp were fed a 38% crude protein feed top-coated with astaxanthin krill oil (K) and/or soybean oil (S) at ratios of 0K-3S, 1K-2S, 2K-1S, and 3K-0S% of the diet, as fed basis, respectively. In air-exposed tanks, mean salinity reached 31 ± 6 g/L compared to 36 ± 4 g/L in enclosed tanks. Shrimp survival was similarly high in both rearing systems (90.6 ± 3.8 and 89.2 ± 5.3% in air-exposed and enclosed tanks, respectively) and was unaffected by oil supplementation (P > .05). Shrimp raised in the air-exposed tanks achieved a significantly higher final BW, weekly growth, gained yield, apparent feed intake (AFI) and a lower FCR (feed conversion ratio) compared to animals in the enclosed tanks. As a result of top-coating feed for the air-exposed tanks with the 1K-2S oil mix, the highest shrimp final BW (14.03 ± 0.52 g) and yield (1,515 ± 40 g/m 2 ) could be achieved when compared to the enclosed rearing system and all the other diets. Under longer exposure periods to hypersalinity in enclosed tanks, a minimum of 2K-1S was required to maximize BW (10.80 ± 0.63 g) when compared to the other enclosed diet groups.