Nutrient values of dietary ascorbic acid (l-ascorbyl-2-polyphosphate) on growth, survival and stress tolerance of larval shrimp, Litopenaeus vannamei |
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| Authors: | J NIU L-X TIAN Y-J LIU K-S MAI H-J YANG C-X YE & W GAO |
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| Institution: | Nutrition Laboratory, Institute of Aquatic Economic Animals, School of Life Science, Sun Yat-sen University, Guangzhou, P.R. China;;Laboratory of Aquaculture Nutrition, College of Fisheries, Ocean University of China, Qingdao, P.R. China |
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| Abstract: | l -ascorbyl-2-polyphosphate (ApP) was used as a vitamin C source to investigate the ascorbic acid (AsA) requirements on growth performance and stress resistance of the larval white shrimp, Litopenaeus vannamei . Five isoenergetic and isonitrogenous fish meal-fish protein hydrolysate-based diets with five levels of ApP, AsA equivalent to 91.8, 188, 271, 360 and 436 mg kg?1 diet were fed to triplicate groups of L. vannamei (mean initial wet weight 1 mg) for 32 days. The diet with AsA 91.8 mg kg?1 showed high cumulative mortality after 10 days of feeding. After the 32-day trial, the shrimp that fed the diet had significantly lower survival and weight gain (WG, %) than those that fed 188, 271, 360 and 436 mg AsA kg?1 diets. Specific growth rate (SGR, % day?1) and final body wet weight (FBW, mg) showed the same pattern as WG (%). There were no significant differences in growth performance (FBW, WG and SGR) among the groups that fed 188, 271, 360 and 436 mg kg?1 of AsA at the termination of feeding trial. Broken-line regression analysis on WG indicated that 191 mg AsA kg?1 in the diet was the optimum for larval L. vannamei . On the contrary, dietary level of more than 360 mg AsA kg?1 was needed to ensure high resistance to stressful conditions such as low dissolved oxygen stressors. |
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| Keywords: | larval shrimp l-ascorbyl-2-polyphosphate Litopenaeus vannamei growth stress tolerance survival |
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