Evaluation of selenium sources to ovines

Author(s)

Fernanda Alves de Paiva

• Document type: Doctoral Thesis
• Press: Pirassununga.
• Institution: Universidade de São Paulo (USP). Faculdade de Zootecnica e Engenharia de Alimentos (FZE/BT)
• Defense date: 2006-09-22

Examining board members

Marcus Antonio Zanetti; Marcelo Landim Brisola; Raul Franzolin Neto; João Alberto Negrao; Francisco Palma Rennó

• Advisor: Marcus Antonio Zanetti

Abstract

This research was carried out at FZEA/USP to compare the utilization of organic selenium (Se) sources to sodium selenite in lambs’ diet, through analyses of tissues Se concentrations, liver glutathione peroxidase activity, metabolic balance of Se and bioavailability assay. Forty Suffolk lambs were used and submitted to three sources and three levels of supplementary Se for 84 days. Treatments were: treatment 1: no supplement; treatments 2, 3 and 4: 0.2, 0.8 and 1.4 mg/kg of supplementary sodium selenite-selenium; treatments 5, 6 and 7: 0.2, 0.8 and 1.4 mg/kg of supplementary selenoyeast-selenium; treatments 8, 9 and 10: 0.2, 0.8 and 1.4 mg/kg of supplementary selenomethionine-selenium. Blood samples were taken to Se serum dosage and in the end of the experiment the animals were killed and samples of liver, muscle and kidney were taken to Se concentrations dosage and glutathione peroxidase activity (liver). In the last five days of the experiment, a Se metabolic balance was realized. Bioavailability was calculated by “Slope Ration Assay", using liver, muscle and kidney Se concentrations and glutathione peroxidase activity as parameters. Se sources did not affect Se intake, apparent absorption and retention, glutathione peroxidase activity and Se concentrations in liver, kidney and serum; however, selenium concentrations in muscle of animals supplied with organic sources were higher than in other animals (P<0.0001). Se bioavailability in muscle was higher when organic Se sources were used. Using organic Se sources provides higher accumulation of Se in lambs’ muscle which would provide higher Se intake to consumers of sheep meat. (AU)