title: Growth performance and starch utilization in common carp (Cyprinus carpio L.) in response to dietary chromium chloride supplementation.
abstract: A nutrition trial was conducted on juvenile common carp (Cyprinus carpio), initial mean body weight 15 ± 0.4 g within a controlled facility at 25 ± 0.5°C. Six diets containing various levels of supplementary Cr (0, 0.2, 0.5, 1.0, 1.5, and 2.0) mg Cr/kg of diet as Cr chloride hexahydrate were fed to carp for a period of 10 weeks. Lower growth performance was observed in fish fed on the control diet and the diet supplemented with the highest level of Cr (2.0mg Cr/kg). Although fish fed 0.5mg Cr/kg showed the best growth performance, this was not significantly different (P>0.05) from fish fed 1.0mg Cr/kg. The regression of plasma glucose concentration was linear (R(2)=0.97 and P value=0.001) as the Cr content of the diet increased (up to 1.5mg Cr/kg). Cr carcass content was elevated with an increasing level of dietary Cr supplementation up to 1.5mg Cr/kg; but fish fed on the diet supplemented with the highest level of Cr (2.0mg Cr/kg) showed a decrease in Cr carcass content. Histological examination to evaluate the impact of different Cr supplementation on liver and gut tissues showed notable changes. The higher level of Cr (2.0mg Cr/kg) in the diet gave rise to elevated hepatocyte vacuolization and changes in gut tissue morphology. It appeared that Cr chloride significantly improved growth within a defined range (0.2-1.5) mg Cr/kg without any negative impact, while 2.0mg Cr/kg in carp diet seems to be the threshold for the initiation of toxicity.
authors: School of Biomedical and Biological Sciences, University of Plymouth, Drake Circus, Plymouth PL48AA, UK. arafat.ahmed@plymouth.ac.uk
authors: Arafat R
authors: AR
authors: Ahmed
authors: A John
authors: AJ
authors: Moody
authors: Andrew
authors: A
authors: Fisher
authors: Simon J
authors: SJ
authors: Davies
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D002347:Carps / Q000254:growth & development*; D002712:Chlorides / Q000008:administration & dosage / Q000494:pharmacology*; D002857:Chromium / Q000032:analysis; D017608:Chromium Compounds / Q000008:administration & dosage / Q000494:pharmacology*; D019587:Dietary Supplements; D008099:Liver / Q000187:drug effects / Q000473:pathology; D013213:Starch / Q000737:chemistry / Q000378:metabolism*; D015430:Weight Gain / Q000187:drug effects
chemical_list: D001786:Blood Glucose; D002712:Chlorides; D017608:Chromium Compounds; D002857:Chromium; D013213:Starch; C017133:chromous chloride