Dietary phosphorus affected growth performance, body composition, antioxidant status and total P discharge of young hybrid sturgeon (♀Huso huso × ♂Acipenser schrenckii) in winter months

Abstract

Summary An 8‐week feeding trial was carried out using young hybrid sturgeon (♀Huso huso × ♂Acipenser schrenckii) to study the effects of dietary phosphorus (P) on growth performance, body composition, liver and serum antioxidant status as well as the effluent P content in the wintertime. Four puffed pellet diets were formulated to contain graded total P levels at 0.63, 1.15, 1.85, and 2.12%, respectively. Triplicate groups of hybrid sturgeon (494.21 ± 18.63 g) were reared in concrete ponds (2.0 × 1.2 × 1.4 m), and fed one of the four diets for 8 weeks. Weight gain and feeding rate significantly decreased with increasing dietary P content, and fish fed the 2.12% P diet had negative growth. With the increase in dietary P, whole body ash and P content significantly increased. There was no inverse relationship between the whole body lipid content and dietary P level in young hybrid sturgeon. Hybrid sturgeon liver exhibited higher superoxide dismutase, catalase and glutathione peroxidase activities in the 0.63 and 1.15% dietary P treatment groups than those in the other two groups. Serum alkaline phosphatase activity increased significantly with increasing dietary P. Discharge of P into the pond increased significantly with increasing dietary P. In conclusion, a dietary P content between 0.63 and 1.15% helped young hybrid sturgeon to activate their antioxidant defense system and eradicate the free radicals, in order to reduce the antioxidant damage, while still keeping total P content in the pond at a relatively low level during the winter months.

Effects of dietary phosphorus on growth, body composition and immunity of young taimenHucho taimen(Pallas, 1773)

“…Dietary P levels may affect antioxidant status of fish while that is poorly documented. For instance, hybrid sturgeon liver exhibited higher SOD, CAT and GSH‐Px activities when fed the lower dietary P (Jin, Wang, Tang, Xie & Dai ). In lower P groups (0.33% and 0.56%), no antioxidant responses were observed and this may not have been low enough to affect antioxidant responses of yellow catfish adversely (Zhu, Qiu, Ding, Duan & Wang ).…”

Responses of hybrid sturgeon ( Huso dauricus ♀ × Acipenser schrenckii ♂ ) to oral administration of phosphorus

“…SOD activity affected by dietary P has been evaluated in many studies. Inhibited plasma SOD activity was also found in hybrid sturgeon ( ♀Huso huso × ♂Acipenser schrenckii ) and young taimen ( Hucho taimen ) after feeding low P diet (Jin et al, ; Wang et al, ). In the present study, fish in the low P groups (0 and 50 mg P/kg BW) showed inhibited ALP and SOD activity, indicating that fish were suffering oxidative stress because of the P deficiency.…”

“…In the present study, fish in the low P groups (0 and 50 mg P/kg BW) showed inhibited ALP and SOD activity, indicating that fish were suffering oxidative stress because of the P deficiency. Disturbance of P homeostasis in fish could induce significant physiological effects on fish including oxidative stress (Jin et al, ; Skonberg et al, ). Thus, fish would be susceptible to the outside environment such as pathogens or contaminants at the status of the disturbed homeostasis because of the inappropriate P addition in the diet (Chen et al, ; Sugiura et al, ; Wang et al, ).…”

“…Dietary P requirements are different in different fish species. Based on the existing studies on sturgeon, the requirement of P is ranging from 0.6% to 1.1% (Jin et al, ; Xu et al, ). The P intubation dosages (0, 50, 100 and 200 mg P/kg BW) in this study were amount to 0%, 0.5%, 1% and 2% of P supplementation in fish diet respectively.…”

“…Among the cultured sturgeons, the hybrid Huso dauricus ♀ × Acipenser schrenckii ♂ is one of the most widely cultured species. The requirement and utilization of P in sturgeon were only studied in Siberian sturgeon ( Acipenser baerii ) and hybrid sturgeon ( Huso dauricus ♀ × Acipenser schrenckii ♂ ) so far (Jin, Wang, Tang, Xie, & Dai, ; Xu, Xu, Wang, Zheng, & Sun, ). P requirement and utilization vary with fish species, body weight and season (temperature).…”