The influence of dietary vitamin C and E supplementation on the physiological response of pirarucu, Arapaima gigas, in net culture.
This study evaluated the efficacy of dietary vitamin C (ascorbic acid or AA), vitamin E (alpha-tocopherol or alpha-T), and C+E supplementation on the blood parameters of Arapaima gigas grown in net cages for 45 days. Four treatments were tested: control (commercial feed); C800; E500 and C+E (800+500) with supplementation of 800 mg AA kg(-1), 500 mg alpha-T kg(-1) and 800+500 mg AA+alpha-T kg(-1), respectively. Hematocrit (Ht), red blood cells (RBC), and hemoglobin concentration (Hb) (oxidative status indicators), thrombocytes and leukocytes (immunological indicators), plasma protein and glucose were evaluated. Fish fed vitamin C and C+E supplemented diets showed greater weight gain and survival. Dietary vitamin C and C+E diet supplementation resulted in increased Ht, Hb, RBC, MCHC, total leukocytes, total proteins, thrombocytes and eosinophils compared to the control and alpha-T. The alpha-tocopherol-supplemented diet reduced the number of total thrombocytes, lymphocytes and neutrophils and increased glucose and eosinophils relatively to the control. In general, leukocytes and thrombocytes were good indicators of the efficiency of vitamin on the defense mechanism of the A. gigas reared in cages. Results indicate that high alpha-T diet supplementation provides no benefit for the maintenance of the oxidative or the immunological status of A. gigas. However, it was demonstrated that high dietary AA improves A. gigas immunological status. Red blood cell indices and immune system indicators showed no synergistic effect between the vitamins after supplementing the A. gigas diet with alpha-T+AA.
de Menezes
Glauber Cruz
GC
Department of Aquaculture, INPA (Amazonian National Research Institute), Av. André Araújo, 2936, P.O. Box 478, Manaus, AM 69069-001, Brazil.
Tavares-Dias
Marcos
M
Ono
Eduardo Akifumi
EA
de Andrade
Jaqueline Inês Alves
JI
Brasil
Elenice Martins
EM
Roubach
Rodrigo
R
Urbinati
Elisabeth Criscuolo
EC
Marcon
Jaydione Luiz
JL
Affonso
Elizabeth Gusmão
EG
D000818:Animals; D017756:Aquaculture / Q000379:methods*; D001205:Ascorbic Acid / Q000008:administration & dosage*; D001786:Blood Glucose / Q000378:metabolism; D001798:Blood Proteins / Q000378:metabolism; D004032:Diet; D004906:Erythrocyte Count; D004909:Erythrocyte Indices; D005399:Fishes / Q000254:growth & development / Q000502:physiology*; D006400:Hematocrit; D006454:Hemoglobins / Q000378:metabolism; D007958:Leukocyte Count; D010976:Platelet Count; D014810:Vitamin E / Q000008:administration & dosage*
D001786:Blood Glucose; D001798:Blood Proteins; D006454:Hemoglobins; D014810:Vitamin E; D001205:Ascorbic Acid