Preliminary Study of the Dietary α‐Tocopherol Requirement in Sea Cucumber, Apostichopus japonicus

Abstract

This study was conducted to evaluate the dietary α‐tocopherol (vitamin E) requirement in juvenile sea cucumber, Apostichopus japonicus. Sea cucumbers averaging 1.48 ± 0.07 g (mean ± SD) were randomly distributed into 18 rectangular plastic tanks of 20 L capacity in a recirculating system (20 animals per tank). Six semi‐purified experimental diets with average protein and crude lipid levels (dry matter) of 29.7 ± 0.36% and 4.39 ± 0.23% (mean ± SD), respectively were formulated to contain 0 (E4), 15 (E12), 30 (E23), 60 (E44), 120 (E77) and 600 (E378) mg α‐tocopherol/kg diet, supplied as dl‐α‐tocopheryl acetate. Diets were analyzed for α‐tocopherol content by HPLC and the α‐tocopherol levels were 4.01, 12.4, 23.1, 44.3, 77.4 and 378 mg α‐tocopherol/kg diet for E4, E12, E23, E44, E77 and E378 diets, respectively. Casein and defatted fish meal were used as the protein sources in the diets while wheat flour was the carbohydrate source. Sea cucumbers were fed each of the six experimental diets in triplicate groups. At the end of the 14‐week feeding trial, weight gain (WG), specific growth rate (SGR) and feed efficiency (FE) of sea cucumbers fed on E23, E44, E77 and E378 diets were significantly (P < 0.05) higher than those of animals fed on E4 and E12 diets. However, there were no significant differences in WG, SGR and FE among sea cucumbers fed on E23, E44, E77 and E378 diets or among those fed on E4 and E12 diets. Survival of sea cucumbers fed on E44, E77 and E378 diets were significantly higher than those of animals fed on E4, E12 and E23 diets. However, there were no significant differences among sea cucumbers fed on E4, E12 and E23 diets or among those fed on E44 and E77 diets. Whole‐body vitamin E concentration increased with α‐tocopherol content of the diets. Broken line analysis of WG showed an optimum dietary α‐tocopherol requirement of 41 mg α‐tocopherol/kg diet in sea cucumber. These results indicated that the optimum dietary α‐tocopherol requirement in sea cucumber in the form of dl‐α‐tocopheryl acetate could be higher than 23.1 mg α‐tocopherol/kg diet but lower than 44 mg α‐tocopherol/kg diet.

Vitamin E requirement of sea cucumber (Apostichopus japonicus) and its' effects on nonspecific immune responses

“…In our study the highest specific growth rate (67%) is lower than earlier report (87%) (Ko et al . ), but the survive is higher than the Ko's report. The reason may be because the weight of the sea cucumber is different, and in our study the sea cucumbers are 7.96 g and the reports of Ko et al .…”

“…The result is higher than the former report (23.1–44 mg kg −1 ) (Ko et al . ) on sea cucumber, and the main reason maybe the growth stage and the basic diets that are different.…”

“…It has also been studied in Atlantic salmon (Hardie, Fletcher & Secombes ), beluga (Amlashi, Falahatkar, Sattari & Gilani ), Nile tilapia (Lim, Yildirim‐Aksoy, Li, Welker & Klesius ) and shrimp (Lee & Shiau ). It was reported that the optimum dietary α‐tocopherol requirement in juvenile sea cucumber (1.48 ± 0.07 g) in the form of dl‐α‐tocopheryl acetate is about 23.1–44 mg kg −1 (Ko, Go, Okorie, Kim, Lee, Yoo & Bai ). However, a role for dietary vitamin E in growth and nonspecific immune responses of sea cucumber has not been reported.…”

Requirement of vitamin E of growing sea cucumberApostichopus japonicusSelenka

“…In this trial, WG and SGR presented the trend of first rising and then kept stable, which were in agreement with hybrid tilapia, Oreochromis niloticus × O. aureus (Huang et al, 2003) and grass carp, Ctenopharyngodon idellus . It can be concluded from Ko et al (2009), and our trial that the requirement of vitamin E was increased with the increasing of animal's size and age, which was contrast to the protein requirement of common dentex, Dentex dentex L. (Skalli, Hidalgoa, Abellán, Arizcun, & Cardenete, 2004). It can be concluded from Ko et al (2009), and our trial that the requirement of vitamin E was increased with the increasing of animal's size and age, which was contrast to the protein requirement of common dentex, Dentex dentex L. (Skalli, Hidalgoa, Abellán, Arizcun, & Cardenete, 2004).…”

“…With WG as an evaluating indicator, dietary optimum vitamin E for growing sea cucumber was 187.2 mg/kg diet. It can be concluded from Ko et al (2009), and our trial that the requirement of vitamin E was increased with the increasing of animal's size and age, which was contrast to the protein requirement of common dentex, Dentex dentex L. (Skalli, Hidalgoa, Abellán, Arizcun, & Cardenete, 2004). There was no vessellike transporting system in sea cucumber, and lipids were exposed to oxygen directly, so that more antioxidants were needed for protecting the damage caused by free radicals, meanwhile, this may be the reason why the dietary lipid requirement for sea cucumber was much lower than fish (Liao et al, 2017;Seo & Lee, 2011).…”