title: Partition and metabolic fate of dietary glycerol in muscles and liver of juvenile tilapia.
abstract: This study investigated the effect of dietary glycerol on the metabolism of juvenile tilapia (Oreochromis mossambicus) and to determine its metabolic fate. The experimental diets contained 0% (Group CON), 5% (Group G5) and 15% glycerol (Group G15) and were fed for 40 d to apparent satiation, three times a day. For the metabolism trials, six fish from each treatment were randomly chosen and tube-fed with five pellets labelled with14C-glycerol [14C(U)] in order to evaluate the absorption, catabolism, retention and partition of glycerol in muscle and liver. Group G5 presented the highest14C-glycerol retention and the lowest catabolism, with no significant differences between Groups CON and G15. In Group CON, the highest percentage of14C was incorporated in muscle lipids; with no significant differences between Groups G5 and G15. Furthermore, no treatment effects were found for hepatic14C-lipid and for14C in hepatic and muscle non-lipid extract. In the non-lipid and non-protein fraction, the highest radioactivity was measured in livers of Group G5, however no significant differences were found for this fraction between Groups CON and G15 in liver and for all treatments in muscle. The results of the present study can have practical implications in diet formulations for tilapia and for other aquaculture species with similar feeding pattern since juvenile tilapia are able to metabolise dietary glycerol into lipids, protein and/or carbohydrates and to use it as energy source.
authors.affiliation: a ICA, Agricultural Sciences Institute , Federal University of Minas Gerais , Montes Claros , Brazil.|c CCMAR, Center of Marine Sciences , Algarve University , Faro , Portugal.
authors.forename: Diego Vicente
authors.initials: DV
authors.lastname: da Costa
authors.affiliation: b SPAROS Lda. , Empresarial Area of Marim , Olhão , Portugal.
authors.forename: Jorge
authors.initials: J
authors.lastname: Dias
authors.affiliation: c CCMAR, Center of Marine Sciences , Algarve University , Faro , Portugal.
authors.forename: Rita
authors.initials: R
authors.lastname: Colen
authors.affiliation: d Animal Science Department , Federal University of Lavras , Lavras , Brazil.
authors.forename: Priscila Vieira
authors.initials: PV
authors.lastname: Rosa
authors.affiliation: c CCMAR, Center of Marine Sciences , Algarve University , Faro , Portugal.
authors.forename: Sofia
authors.initials: S
authors.lastname: Engrola
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D004032:Diet / Q000662:veterinary; D004040:Dietary Carbohydrates / Q000378:metabolism*; D005990:Glycerol / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D009132:Muscles / Q000378:metabolism*; D011897:Random Allocation; D017210:Tilapia / Q000378:metabolism*
chemical_list: D004040:Dietary Carbohydrates; D005990:Glycerol
keywords: Bioavailability; Tilapia mossambica; energy metabolism; fish nutrition; glycerol; radioactive tracers