Abstract:
In order to investigate the effects of adding resveratrol to the feed on the growth performance, health status and ammonia nitrogen tolerance of
Micropterus salmoides, the experiment was conducted on largemouth bass with an average body mass of (7.40±0.05) g. The fish were randomly divided into three groups, each with three replicates of 30 fish each, and were fed with experimental feeds containing 0.00%, 0.50% and 1.00% of resveratrol, and saturated feeding was carried out twice a day for 56 d. The results showed that supplementing the diet with resveratrol significantly enhanced the weight gain rate, protein efficiency rate and food intake, and reduced the feed conversion ratio; increased the serum total protein (TP), albumin (ALB) and globulin (GLB) contents, and decreased the triglyceride (TG), cholesterol (TC), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) contents; increased the activities of total antioxidant capacity (T-AOC), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) in liver, decreased the contents of tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1), and interleukin-8 (IL-8); up-regulated the mRNA expression of superoxide dismutase (
sod), catalase (
cat), glutathione reductase (
gr),
glutathione peroxidase (
gpx), and b-cell lymphoma 2 (
bcl-2) genes, and down-regulated the expression of interleukin-1 (
il-1), interleukin-8 (
il-8), tumor protein 53 (
p53), bcl-2 associated X protein (
bax), cysteine aspartate protease 3 (
caspase3) and cysteine aspartate protease 9 (
caspase9) genes. After 96 h of ammonia exposure, the cumulative mortality and blood ammonia content in resveratrol group were significantly lower than those in control group; but the serum lysozyme (LZM) activity, total complement (CH50), total immunoglobulin contents (IG), antibody titer (Ab titer), the activities of argininosuccinate synthetase (ASS), argininosuccinate lyase (ASL), arginase (ARG), and ornithine carbamoyltransferase (OTC) in liver were significantly higher than those in control group. The study showed that the addition of resveratrol to the feed could improve the growth performance, serum health, antioxidant capacity, inflammation and apoptosis of largemouth bass, and that resveratrol could enhance the ammonia-nitrogen tolerance of largemouth bass by activating the urea cycle, and improve the immune response to the occurrence of stress.