The Effect of Feeding with Different Dietary Protein Levels on Haematological Profile and Leukocytes Population of Juvenile Paddlefish, Polyodon spathula

Abstract

The aim of this paper is to evaluate the haematological parameters and the leukogram of paddlefish juveniles fed with different protein level diets. The experiment was conducted in a recirculating system, populated with 112 days old paddlefish juveniles with a mean weight of 57.93 g. During the experiment, two different types of pellets were tested: Aller Performa (54% crude protein) at variant V1 (B1, B3) and Classic Extra 1P (41% crude protein) at variant V2 (B2,B4). The haematological parameters analyzed were: RBC, Hb, Ht, MCV, MCH and MCHC. In V1 case, RBC, Hb, Ht and MCV registered lower values than those from V2 while MCH and MCHC were higher. By study all the different types of leukocyte found on blood smears (lymphocytes, monocytes and granulocytes), the leukogram was determined. The physiological stress induced by different protein level diets reflected the absolute number of leukocytes. Thus, at V2, the value of 82.05 x 103 WBC/mm3blood was significantly higher than the one from V1 (50.80 x 103 WBC/mm3blood). A decrease of lymphocytes percentage was observed in case of V1 (59%), comparing to V2 (71.125%). This shows a decrease of fish immunity, but in exchange, the percentage of neutrophils increased. As a conclusion, in terms of physiological condition, percentage of 41% crude protein (V2) led to a better health condition of paddlefish juveniles.

Keywords

• haematological profile
• leukograma
• polyodon spathula
• recirculating aquaculture system