Dietary vitamin A requirement ofSillago sihamaForskál

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.

Modulation of growth, immunity and antioxidant‐related gene expressions in the liver and intestine of juvenileSillago sihamaby dietary vitamin C

“…The actual VC concentration was detected to be 5, 16, 27, 65, 122 and 233 mg/kg, respectively, according to the method of Ai et al (). The concrete method and process of mixing ingredients, pelletizing, drying and storing were according to our previous study (Huang et al, ). The grain diameter of feeds was 1–2.5 mm.…”

“…sihama has been finished in south China (Huang, Du, & Huang, ), more researches were conducted on this species (Zhou, Huang, Du, & Huang, ). As we knew, there was limited study about the nutritional requirements of this fish, except the studies about optimal dietary protein and lipid levels (unpublished data), dietary n‐3 highly unsaturated fatty acid (HUFA) requirement (He et al, ) and vitamin A requirement (Huang et al, ) for this fish. Study on nutritional requirements would further complete foundation database building in artificial formula feed for S .…”

Liver immune parameters, complement pathway, inflammatory factor and TOR genes expression of silver sillago, Sillago sihama , fed with diets replacing fish meal with low‐gossypol cottonseed meal

“…Few studies have addressed nutrition in S. sihama, aside from our laboratory studies that investigated vitamin A, vitamin C and vitamin E requirement in the species (Huang et al, 2018. In addition, the lack of exclusive forage production is due to the paucity of nutritional physiology research, leading to the use of shrimps or marine fish diets to cultivate the S. sihama.…”

Effects of two dietary protein levels on growth, body composition, intestinal microflora and expression of TOR, IGF‐I, LPL and HSP70 of juvenile silver sillago,Sillago sihama

“…The silver sillago, Sillago sihama (S. sihama), is mainly found in the coastal areas of China and the shallow waters of the western Indian Pacific (Guo et al, 2014;Huang et al, 2018). As a critical economic fish in coastal parts of China, it is deeply loved by people on its excellent meat quality and high economic and nutritional value.…”

“…Although our laboratory studies have investigated the requirements of this species for vitamin A, vitamin C and vitamin E (Huang et al, 2018(Huang et al, , 2020a, effects on the intestinal microflora under different nutritional conditions have not been reported for this species.…”