Effects of dietary humic acid on growth performance, haemato-immunological and physiological responses and resistance of Rainbow trout, Oncorhynchus mykiss to Yersinia ruckeri

YILMAZ S., ERGÜN S., ÇELİK E. Ş., YİĞİT M.

AQUACULTURE RESEARCH, vol.49, no.10, pp.3338-3349, 2018 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 49 Issue: 10
  • Publication Date: 2018
  • Doi Number: 10.1111/are.13798
  • Journal Name: AQUACULTURE RESEARCH
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.3338-3349
  • Keywords: digestive enzyme, humic acid, immunological responses, rainbow trout, yersiniosis
  • Çanakkale Onsekiz Mart University Affiliated: Yes

Abstract

This study investigated the effects of dietary humic acid sodium salt on growth performance, haemato-immunological and physiological responses, and resistance of rainbow trout, Oncorhynchus mykiss to Yersinia ruckeri. The experimental fish were divided into four groups; three of them were fed with humic acid incorporated diets (0.3% H3, 0.6% H6, 1.2% H12) and an additive free basal diet served as the control. Growth performance and haematological parameters of rainbow trout were not affected by humic acid supplemented diets (p > 0.05). However, dietary humic acid especially with 0.6% incorporation significantly increased stomach pepsin, intestinal trypsin and lipase activities p < 0.05. Following 60 days of feeding trial, fish were challenged with Yersinia ruckeri for 20 days. At the end of the challenge period, significantly higher (p < 0.05) survival rates were found in the 6% humic acid group compared to all other experimental treatment. Thus humic acid might replace antibiotics in diets for rainbow trout to control yersiniosis.