Effects of Dietary Savory and Myrtle Essential Oils on Growth, Survival, Nutritional Indices, Serum Biochemistry, and Hematology of Farmed Rainbow Trout, Oncorhynchus mykiss, Fry

Abstract

The effects of diets containing different levels of essential oils from savory Satureja khuzestanica Jamzad and myrtle Myrtus communis L and an immunity complement were investigated on growth, survival, nutritional indices, serum biochemistry, and hematology of farmed rainbow trout, Oncorhynchus mykiss, fry (n = 4500; 5 ± 2 g). The essential oils were dosed as 300 and 500 mg/kg diet. After 60 d, the fish fed 300 mg/kg of the essential oils showed the highest counts of white blood cells (P < 0.05). The same treatment revealed the greatest levels of hematocrit, total protein, and albumin, but glucose and cholesterol values significantly decreased compared with the control (P < 0.05). Feeding fish with 300 mg/kg of the essential oils led to highest records of specific growth rate and survival rate but the lowest feed conversion ratio (FCR), and those fed with immunity complement attained the lowest values of growth parameters. The fry fed with immunity complement and 300 mg/kg of myrtle essential oil achieved the highest and lowest FCR values, respectively. The results indicate that dietary supplementation of 300 mg/kg of the above essential oils exert positive impacts on the growth performance, feeding efficiency, and hematological factors in O. mykiss.

Tarragon (Artemisia dracunculus) Essential Oil at Optimized Dietary Levels Prompted Growth, Immunity, and Resistance to Enteric Red-Mouth Disease in the Rainbow Trout (Oncorhynchus mykiss)

“…The TP levels increased in response to TGO, while CHOL, TRIG, GLU, and CORT levels reduced in TGO-treated fish. Increases in TP after essential oil supplementation have been reported by some studies, which was in agreement with our results [80][81][82]. TP concentrations in fish blood can be changed in response to nutritional and immune conditions.…”

“…The feeding of the fish with diet containing TGO significantly reduced CHOL and TRIG levels. Similar results have been also reported the reduced in CHOL and TRIG levels in fish blood after PEO supplementation [81,82,89,90]. It seems that PEO such as TGO prevents hyperlipidemia and fat accumulation by affecting the biosynthesis and metabolism of lipids, although the exact mechanism is not yet understood [89,91].…”

Citral as food additive for common snook - zootechnical parameters and digestive enzymes

“…The search for the maximum food efficiency has promoted the use of dietary additives to control harmful agents to the digestive process and thus improve the zootechnical indexes. Several essential oils (EOs) have been used as dietary additives for fish, improving growth and resistance to diseases ( ZHENG et al, 2009;FERREIRA et al, 2014;SÖNMEZ et al, 2015;MOHAMADI SAEI et al, 2016;BRUM et al, 2017;ZEPPENFELD et al, 2016ZEPPENFELD et al, , 2017.…”

Incorporation of Rapa Whelk (Rapana venosa) meal in diets for rainbow trout (Oncorhynchus mykiss) fry

“…For instance, Mohamadi Saei et al. (2016) fed rainbow trout fry (5 ± 2 g) with a commercial diet for 8 weeks and reported FCR and SGR values to be 1.05 and 1.01 respectively. In a different study, Yigit, Koca, et al.…”