Effect of Dietary Nano-Selenium on Resistance to Infectious Hematopoietic Necrosis Virus in Rainbow Trout Oncorhynchus mykiss
In order to investigate the effect of dietary nano-selenium on resistance to infectious hematopoi-etic necrosis virus(IHNV)in rainbow trout Oncorhynchus mykiss,juvenile rainbow trout with body weight of(20±2)g were reared in a circular pond with a diameter of 1.2 m and a height of 0.6 m,with a water depth of 0.3 m,and fed the basic diet containing 0(control),1.0,2.0 and 5.0 mg/kg nano-seleni-um,prepared by the mixture of nano selenium with water at 1:30,and evenly spay on the surface of the basic diet,at water temperature of 17-18 ℃ for 7 days.Then,the rainbow trout was injected by 0.2 mL of IHNV solution with concentration of 1×105 pfu/mL and returned to the original ponds for further feed-ing,and liver and tail vein blood samples were collected after anesthesia with 50 mg/L MS-222 on the 7th day in the feeding trial and 1,2 and 3 days after challenge,respectively,and the differences in liver immu-nity and antioxidant-related enzyme activities,immune-related gene expression and serum antibody levels were compared between the rainbow trout groups.The results showed that there were significant increase in the activities of GSH-PX and serum TNF-α in liver of rainbow trout before infection,and addition of 1 mg/kg of nano-selenium(P＜0.05)and significant increase in the expression levels of MX-1 and IL-1βgenes in the addition of 5 mg/kg of nano-selenium group(P＜0.05).The levels of serum TNF-α,C3 andIL-1β antibodies as well as hepatic CAT activity were shown to be significantly elevated on the 1 st to 3 rd day in the rainbow trout fed the diets added with nano-selenium and challenged in each group(P＜0.05),and significant reduce in the MDA content in the liver on the 3 rd day(P＜0.05).Significantly(P＜0.05)increase in hepatic GSH-PX viability,VIG-1,MX-1 and TNF-α gene expression was observed in the rain-bow trout in the addition of 2 and 5 mg/kg of nano-selenium groups(P＜0.05).The findings indicated that addition of nanosized selenium to the diet led to increase the hepatic immunity and antioxidant capacity as well as the serum antibody level in rainbow trout,thus enhancing their resistance to IHNV.
万方数据
维普
