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Keywords:

  • Azomite;
  • digestive enzymes;
  • disease resistance;
  • growth;
  • immune function;
  • Litopenaeus vannamei

Abstract

This study was conducted to evaluate effects of dietary Azomite, a natural mineral of volcanic ash, on growth performance, digestive enzyme activities, serum non-specific immunity and disease resistance of white shrimp (Litopenaeus vannamei). Graded levels of 0.0 g kg−1 (control group), 2.0, 4.0, 6.0 and 8.0 g kg−1 Azomite were supplemented in basal diet to feed shrimps. After 6 weeks feeding, weight gains of the 2.0 and 4.0 g kg−1 Azomite groups were significantly higher than that of the control group (< 0.05). Compared with control group, the activities of stomach protease, hepatopancreas lipase, and serum alkaline phosphatase, lysozyme and phenoloxidase were significantly increased by the 4.0 g kg−1 Azomite addition (< 0.05). When subjected to hypoxia stress, the lethal times of the first shrimp and all shrimps were both delayed by the addition of 2.0–6.0 g kg−1 Azomite to diets, compared with the lethal time of control group. At the 96th hour after the injection of bacterium (Vibrio alginolyticus), the accumulated mortality of 4.0 g kg−1 Azomite addition group was 34.6% lower than that of control group (< 0.05). The results showed that dietary levels of 2.0 and 4.0 g kg−1 Azomite can improve the growth performance, digestive enzyme activities, serum non-specific immune function and disease resistance of white shrimp.