Dietary vitamin A requirement of Sillago sihama Forskál |
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| Authors: | Qin‐cheng Huang Amoah Kwaku Tao Du Bei‐ping Tan Shu‐yan Chi Qi‐hui Yang Shuang Zhang Hong‐yu Liu Xiao‐hui Dong Yuan‐zhi Yang |
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| Affiliation: | 1. Laboratory of Aquatic Nutrition and Feed, College of Fisheries, Guangdong Ocean University, Zhanjiang, Guangdong, China;2. Key Laboratory of Aquatic, Livestock and Poultry Feed Science and Technology in South China, Ministry of Agriculture, Zhanjiang, Guangdong, China;3. Marine Biology Research Base, Guangdong Ocean University, Zhanjiang, Guangdong, China |
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| Abstract: | A 56‐day growth trial was performed to dietary vitamin A (VA) requirement of Sillago sihama Forsskál (S. sihama) with an initial weight of 2.05 ± 0.15 g (mean ± SE). Quadruplicate groups of 40 juveniles per tank were fed with diets containing 362, 751, 1,141, 2,202, 4,335, 8,230, and 18,932 IU VA/kg diet respectively. Haemorrhages, erosion, greater mortality, and sluggish movement were found in fish of the control, whereas fish fed the 18,932 IU VA/kg diet appeared poor appetite. The weight gain rate (WG), specific growth rate (SGR) were highest at the level of 2,202 IU VA/kg diet, and the feed conversion ratio (FCR) showed the minimum at the same level. Compared with the control, groups 1,141–18,932 IU VA/kg showed significantly higher hepatic lysozyme (LZM) activity. Superoxide dismutase (SOD) at level of 751–4,335 IU VA/kg increased significantly than it in the control and reached a plateau after 4,335 IU VA/kg. Alkaline phosphatase (AKP) decreased significantly at level of 8,230–18,932 IU VA/kg diet than it in the control. Total antioxidation capability (T‐AOC), catalase (CAT), and glutathione peroxidase (GSH‐Px) in liver tended to increase and kept stable at level of 8,230 and 18,932 IU VA/kg diet. Fish fed 2,202 IU VA/kg diet showed significantly higher intestinal Na+‐K+ ATPase activity than it in other groups. The broken‐line model based on WG and maximum liver VA concentration indicated that the VA requirement was of 2,516 and 4,334 IU VA/kg respectively. |
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| Keywords: | growth requirement Sillago sihama Forská l vitamin A |
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