Influence of dietary fatty acid composition on enzymatic activity and digestive histology in silver catfish (Rhamdia quelen)

Suzete Rossato,Rafael Lazzari,Isadora Liberalesso De Freitas,Alexandra Pretto,João Radünz Neto,Eduardo Cargnin Ferreira

doi:10.33448/rsd-v10i3.12530

Abstract

Dietary fatty acids may influence the development of the digestive tract and initial activation of digestive enzymes in fish. The objective of this study was to evaluate the effect of the diet lipid profile on ontogeny and activity of digestive enzymes in silver catfish post larvae fed practical diets. Five diets were tested, replacing broiler liver by soybean protein concentrate (SPC) or fish meal (FM): Standard, 15SPC, 30SPC, 15FM and 30FM. The enzymatic activity of fish was analyzed from 32 Hours after fertilization (Haf). Were analysed acid protease, trypsin, chymotrypsin, lipase, amylase and maltase. The development of the digestive system was analyzed from first feeding up to 28 days by histological techniques. The enzymatic activity presented peaks for the post-larvae fed with the 15SPC diet and fish fed with diet 15FM showed best growth. The development of the digestive system did not suffer damage from the diets offered. Post-larvae fed the 30SPC diet showed reduced development of the digestive tract. The diet 15FM provide good lipid profile for silver catfish post larvae.

Highlights

Digestive enzymes act according to the diet composition and the dietary habits of fish (Mente et al, 2017)
The main essential fatty acids that should be present in early fish diets are 22: 6n-3, 20: 5n-3 and 20: 4n-6, and their ratio should be adequate for proper fish development (Sargent et al, 1999; El Kertaoui et al, 2019)
The objective of this study was to evaluate the effect of the diet lipid profile on ontogeny and activity of digestive enzymes in silver catfish post larvae fed practical diets

Summary

Introduction

Digestive enzymes act according to the diet composition and the dietary habits of fish (Mente et al, 2017). The first gastric glands can be detected a few days or weeks after hatching and their numbers progressively increase by covering the epithelium of the stomach (Zambonino Infante et al, 2008; Alveal et al, 2019). The stomach in some species is not differentiated during the first days of life (Teles et al, 2017) The development of these organs and gastric glands appears at different ages for the various species of fish (Zambonino Infante and Cahu, 2007; Teles et al, 2017; Alveal et al, 2019). At 16Haf, differentiation of the digestive tract is complete, presenting oropharyngeal cavity, esophagus, liver, pancreas, stomach and intestine (Silveira et al, 2013)

Objectives

Methods

Results