Dietary Artemisia, Artemisia annua, supplementation improves common carp welfare under high stocking density

Abstract

Intensive aquaculture supports higher production per unit of area, but it may be associated by stress and health problems in fish. Thus, researches are continuing to find applicable methods for suppressing such negative effects. Dietary supplementation with medicinal plant is known as a promising method in this field. Accordingly, the present study aimed at assessing the benefits of dietary Artemisia, Artemisia annua, supplementation (0, 2.5, 5 and 10 g/kg) on growth performance, stress, antioxidant and immunological responses of common carp, Cyprinus carpio, held at a high stocking density (10 g/L vs. 3 g/L) for 70 days. Increase in fish stocking density significantly (p < 0.05) reduced growth performance, haematological parameters (red blood cell, haematocrit, haemoglobin, leukocyte and lymphocyte) and immune responses (total protein, complement and total immunoglobulin), but increased neutrophil, lysozyme, stress responses (cortisol, glucose, aspartate aminotransferase and lactate dehydrogenase), antioxidant enzymes’ activities (superoxide dismutase, catalase and glutathione peroxidase) and lipid peroxidation. Artemisia supplementation significantly (p < 0.05) restored haematological parameters, leukocyte count and mitigated the changes in lymphocyte, neutrophil, stress and immunological parameters, antioxidant enzymes’ activities and lipid peroxidation. Based on the results, dietary Artemisia supplementation is not capable to restore growth retardation of common carp under high stocking density; however, it mitigates the adverse effects of high stocking density on haematological, antioxidant and immunological parameters. Supplementation at 5 g/kg is recommended for carp feed formulation.