Effects of dietary vitamin D3 on the growth and antioxidant capacity of largemouth bass (Micropterus salmoides)

Abstract:

In order to explore the effects of vitamin D₃ content in the feed on growth performance, calcium and phosphorus metabolism, liver antioxidant capacity, serum biochemical indexes and anti-infection ability of largemouth bass, Micropterus salmoides, 0 IU/kg, 15 IU/kg, 30 IU/kg, 45 IU/kg and 60 IU/kg vitamin D₃ were added to the basic feed respectively. Five kinds of isonitrogenous and isoenergetic experimental diets feeds with vitamin D₃ contents of 1 370 IU/kg, 1 385 IU/kg, 1 400 IU/kg, 1 415 IU/kg and 1 430 IU/kg were set up. The largemouth bass with an initial body mass of (14.19±0.05)g was reared for nine weeks. The results showed that different levels of vitamin D₃ in the feed significantly affected the mass gain rate, specific growth rate and feed conversion rate of largemouth bass, but had no significant effect on survival rate, condition factor and viscera ratio. The addition of vitamin D₃ significantly reduced the liver to body ratio of largemouth bass. With the increase of vitamin D₃ content in the feed, the contents of crude ash, calcium and phosphorus and serum calcium ions in the spine of largemouth bass increased. However, there was no significant effect on the content of crude protein, crude fat, crude ash and moisture in the muscle. The total superoxide dismutase activity, catalase activity and total antioxidant activity in the liver of largemouth bass were significantly increased by the addition of vitamin D₃ in the feed, and the activity of transaminase in the serum was significantly decreased. The anti-infection ability of the body to Aeromonas hydrophila was also enhanced with the increase of vitamin D₃ content in the feed. All the results indicated that dietary vitamin D₃ between 1 370 IU/kg and 1 430 IU/kg could improve growth and health of largemouth bass.