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

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.

Effects of sodium diformate on growth performance, gut microflora, digestive enzymes and innate immunological parameters of Asian sea bass ( Lates calcarifer ) juveniles

“…In the current study, among different pancreatic enzymes analysed only specific activity of chymotrypsin improved in fish fed diets administered with NaDF compared to the control group. Other studies reported that pancreatic digestive enzymes increased by administrating dietary OA such as citric acid in hybrid tilapia ( O. niloticus × Oreochromis aureus , Li, Li, & Wu, ), western whiteleg shrimp (Su et al, ) and red drum ( S. ocellatus , Castillo et al, ), and humic acid in rainbow trout (Yilmaz, Ergun, Celik, & Yigit, ). In this regard, da Silva et al () evaluated in vitro pancreatic enzyme activity in western whiteleg shrimp and found that trypsin and chymotrypsin activity increased in the presence of acetate and propionate, but decreased in the presence of lactate and citrate.…”

Dietary trans‐cinnamic acid application for rainbow trout (Oncorhynchus mykiss): II. Effect on antioxidant status, digestive enzyme, blood biochemistry and liver antioxidant gene expression responses

“…Other tissues were weighed in Eppendorf tubes after by adding cold distilled water ten times their weight on them. Samples were centrifuged, and upper phases of them were stored at −80°C until digestive enzyme analyses (Yılmaz, Ergun, Çelik, & Yigit, ).…”

“…The pH values in feed particles, the intestines (from pyloric caeca to anus) and stomach were measured using a pH meter after weighing the samples and diluting for ten times with distilled water as earlier described by Yilmaz, Ergun, Çelik et al (). The concentration of pepsin, amylase, lipase, alkaline phosphatase and trypsin was estimated from the absorbance at 280 nm, 540 nm, 405 nm, 405 nm and 410 nm, respectively, according to the methods previously conducted and described in our laboratory (Yilmaz, Ergün, et al, ).…”

Effect of dietary supplementation with a synbiotic (Lacto Forte) on growth performance, haematological and histological profiles, the innate immune response and resistance to bacterial disease inOreochromis niloticus

“…Thus, the scientific community has begun to search for alternative non‐antibiotic‐related strategies, including phage therapy, immunostimulant therapy, treatment with dietary herbal medications (Mabrok & Wahdan, ; Newaj‐Fyzul & Austin, ; Yilmaz, ; Yılmaz & Ergün, ; Yılmaz, Ergün, & Soytaş, ; Yilmaz, Ergün, & Turk, ), and supplementation with organic acids (Yilmaz, ; Yılmaz & Ergün, ; Yılmaz, Ergun, Çelik, & Yigit, ; Yilmaz, Ergün, & Yıgıt, ), probiotics, prebiotics and synbiotics (Defoirdt, Sorgeloos, & Bossier, ; Di Bartolomeo, Startek, & Van den Ende, ; Gatesoupe, ).…”