Effects of herbal supplements on growth performance of sea bass (Dicentrarchus labrax): Change in body composition and some blood parameters

This study was conducted to investigate the effects of dietary thyme (Thymus vulgaris), rosemary (Rosmarinus officinalis) and fenugreek (Trigonella foenum graecum) as feed additives on growth performance, proximate composition and ammonia excretion of European 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. The thyme supplementation significantly increased protein efficiency ratio, fillet protein levels, protein and energy retentions (P<0.05). The medicinal herb additives did not change serum urea, uric acid, creatinine and ammonia excretion rate (P>0.05). The results indicate that dietary thyme improved the protein and energy retentions of sea bass.