Effect of Dietary Herbal Supplements on Some Physiological Conditions of Sea Bass Dicentrarchus labrax

Abstract

This study was conducted in order to investigate the effects of dietary thyme Thymus vulgaris, rosemary Rosmarinus officinalis, and fenugreek Trigonella foenum graecum as feed additives on total liver fat levels and biometric indices of Sea Bass Dicentrarchus labrax. Four isonitrogenous (48% crude protein) and isocaloric (21 kJ/g) diets were formulated to contain 0% (control), or 1% of thyme, rosemary, or fenugreek. In a 45-d feeding trial, 12 fiberglass tanks (140 L) were each stocked with 17 fish (20.43 ± 0.03 g). Herbal supplemented diets significantly decreased the total liver fat, visceral fat index, viscerosomatic index, hepatosomatic index, and increased the spleen–somatic index and bile–somatic index (P < 0.05). In conclusion, the results indicated that a dietary level of 1.0% for thyme, rosemary, or fenugreek could improve some of the physiological parameters of Sea Bass. Thus, this work provides a new perspective for the use of medicinal herbs that can be added to fish feed to improve the status of fish organs. Thyme, rosemary, and fenugreek contain a number of different active components, which possibly play an important role in improving these conditions, but the mechanism by which this is achieved needs further and more detailed study.

Received July 19, 2012; accepted January 15, 2013

ACKNOWLEDGMENTS

We thank the Canakkale Onsekiz Mart University Research Fund for financial assistance (project number COMU BAP 2010/79). We also thank Önder Ayyıldız for reviewing the manuscript.