Effects of two sources of chromium on performance, blood and liver lipid levels in nile tilapia (Oreochromis niloticus)
Pires, Kássia AmarizSantos, Dalinne Chrystian Carvalho dosGraça, Décio SouzaMelo, Marília MartinsBarbosa, Fabiano AlvimSoto-Blanco, Benito
Background: Chromium (Cr) is an essential nutrient for both humans and animals. Cr can be found in different sources, both organic and inorganic. In general, the organic forms of Cr are better absorbed than the inorganic forms. The metabolic effects of Cr are affected by the ingested formulation of this element. Several studies have shown that diet supplementation with Cr improves the growth rate, feeding efficiency and carcass composition of land animals, but the nutritional value of Cr to fish is scarcely known. The aim of the present study was to compare two forms of chromium (chelate and yeast) supplemented in the diets of Nile tilapia (Oreochromis niloticus) at different concentrations and their effect on productive performance, blood parameters and the liver concentrations of cholesterol and triglycerides.Materials, Methods & Results: Nine groups with 36 Nile tilapia fish were formed: a control group, four groups supplemented with chromium (Cr) chelate (8.0 ppm, 16.0 ppm, 24.0 ppm, and 32.0 ppm) and four groups supplemented with chromium yeast (0.8 ppm, 1.6 ppm 2.54 ppm, and 3.2 ppm) for six weeks. After this period, the performance of the fish (weight gain, consumption, food conversion and filet yields), blood parameters (glucose, triglycerides, total protein, total cholesterol, HDL, LDL, and VLDL) and liver cholesterol and triglyceride concentrations were measured. dietary supplementation with chromium chelate (8.0 ppm, 16.0 ppm, 24.0 ppm, and 32.0 ppm) and four levels of chromium yeast (0.8 ppm, 1.6 ppm 2.54 ppm, and 3.2 ppm) did not influence the productive performance, filet yield, blood glucose, triglycerides, total protein, total cholesterol, or lipoprotein or the hepatic levels of triglycerides in Nile tilapia. However, the hepatic cholesterol levels were reduced in tilapia supplemented with 3.2 g/kg Cr yeast (2.85 ppm of total Cr in diet), although hepatic triglycerides were not affected.[...](AU)
Texto completo