Abstract
A feeding trial was conducted to assess the impacts of dietary astaxanthin from wall-broken Haemato-coccus pluvialis(WBHPA)on the growth performance,antioxidant status,immune response,and intes-tinal health of rainbow trout(Oncorhynchus mykiss).Six experimental diets were formulated with various concentrations of WBHPA,ranging from 0 to 8.4 g/kg(containing 0 to 125 mg/kg astaxanthin).Each diet was fed to triplicate groups of rainbow trout(mean initial weight of 561 g)twice daily for 9 consecutive weeks.The survival rate and feed intake of fish exhibited no significant differences among the dietary groups(P＞0.05).Similarly,dietary inclusion of 25 to 100 mg/kg astaxanthin did not significantly affect the weight gain and daily growth coefficient(P＞0.05),but excessive inclusion of astaxanthin(125 mg/kg)slightly depressed these parameters(P＜0.05).Dietary inclusion of 25 to 50 mg/kg astaxanthin increased the activities of intestinal digestion and absorption enzymes(lipase,creatine ki-nase,and alkaline phosphatase),while the inclusion of 25 to 75 mg/kg astaxanthin improved the im-mune response of fish.Furthermore,regardless of inclusion level(25 to 125 mg/kg),dietary astaxanthin supplementation strengthened the intestinal mucosal barrier function and improved antioxidant activity,thereby promoting intestinal development.Conclusively,25 to 75 mg/kg astaxanthin from WBHPA was recommended to be included in diets for rainbow trout.
基金项目
National Natural Science Foundation of China(32273152)
Foundation of Kunming Biogenic Co.,Ltd()
Program for Scientific Research Startup Funds of Guangdong Ocean University(060302022007)
Special Project in Key Fields of Universities in Guangdong Province(2022ZDZX4013)
NETL
NSTL
万方数据