Growth performance and antioxidant enzyme activities in rainbow trout (Oncorhynchus mykiss) juveniles fed diets supplemented with sage, mint and thyme oils

Abstract

This study evaluated effects of dietary supplementation of sage (Salvia officinalis), mint (Mentha spicata) and thyme (Thymus vulgaris) oils on growth performance, lipid peroxidation level (melondialdehyde, MDA) and liver antioxidant enzyme activities (superoxide dismutase, SOD; catalase, CAT; glucose-6-phosphate dehydrogenase, G6PD; glutathione reductase, GR; glutathione-S-transferase, GST and glutathione peroxidase, GPx) in rainbow trout (Oncorhynchus mykiss) juveniles. For this purpose, triplicate groups of rainbow trout were fed daily ad libitum with diets containing sage, mint and thyme oils at 500, 1,000 and 1,500 mg kg(-1) for 60 days. While weight gain percentage of fish fed the diets containing sage and thyme oils was significantly higher than the control group, that of fish fed mint oil was the lowest. Similarly, specific growth rate was found to be the highest in all groups of the sage and thyme oil feeding and the lowest in the mint groups. Moreover, feed conversion ratio was significantly higher in the mint oil administered groups. Survival rate was also significantly reduced in the fish fed the diet containing mint oil. It was observed that SOD, G6PD and GPx activities were significantly increased in liver tissues of all the treated fish groups compared to that of control diet-fed group. However, CAT, GST and GR activities were significantly decreased in experimental diet-fed fish groups at the end of the experiment. On the other hand, a significant reduction was found in MDA levels in the fish fed the diets with sage and thyme oils compared to control and mint diets on the 30th and 60th days of experiment. Overall, dietary inclusion of sage and thyme oils is effective in enhancing rainbow trout growth, reduction in MDA and least changing antioxidant enzyme activities at a low level of 500 mg kg(-1) diet, and they can be used as important feed supplements for rainbow trout production.

Growth performance, immune response and disease resistance of rainbow trout (Oncorhynchus mykiss) fedThymus vulgarisessential oils

“…Findings of our study shows that trout fed diets supplemented with T. vulgaris at 0.5-2 ml/kg feed demonstrated an enhancement in the growth performance, but the best results was seen in 0.5 ml/kg feed group. In their study by Sonmez et al (2015), when rainbow trout were fed diets containing thyme oils at 500, 1,000 and 1,500 mg/kg feed for 60 days illustrated a higher weight gain and SGR than the control group, indicating a positive efficacy of thyme oils on the improving of the nutrient utilization by fish. Also, Zaki, ALabib, Nour, Tonsy, and Mahmoud (2012) showed that tilapia (Oreochromis niloticus) fed with thyme at 1% and 2% demonstrated an improvement in the growth performance.…”

“…In contrast, Hoseini and Yousefi (2018) demonstrated thyme extract at 5-20 g/kg feed suppressed AST and ALT levels in rainbow trout during 2 weeks experiment; and Zadmajid and Mohammadi (2017) measured a significant decrease in values of these enzymes in carp (Carassius auratus gibelio) with an increasing in dietary thyme oils up to 800 mg/kg feed. Rainbow trout fed with thyme oils at 500-1,500 mg/kg feed for 2 months exhibited an increase in some antioxidant activities in liver tissues (Sonmez et al, 2015). However, TA B L E 4 Growth performance of rainbow trout fed on diets containing essential oil of Thymus vulgaris at 0.5, 1 and 2 ml/kg feed for 60 days at 17°C microscopic evaluation of some fish tissues (e.g.…”

Plant essential oils as fish diet additives: benefits on fish health and stability in feed

“…() and Sönmez et al . () reported a heating process (40°C) for 3 h, and then, the diet was top‐dressed with fish oil containing carvacrol by slowly mixing in a food mixer.…”

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“…were purchased from NURİ AGA LTD and added to a commercial trout extruded feed (Pınar™, Turkey) at a dose of 0.5, 1.0and 1.5 % by a mixer. The diets were prepared according to the previously described protocol (Sönmez et al, 2015).Mint, thyme and sage oils contained 74 g kg -1 pulegone, 77 g kg -1 carvacrol and 76 g kg -1 1,8-cineole, respectively. Control diet contained no herbal oil.…”