Cultivation of lettuce (Lactuca sativa L.) and rainbow trout (Oncorhynchus mykiss W.) in the aquaponic recirculation system

The present research aimed to examine the effect of dietary phytoextracts supplementation on the growth performance, haematological (white blood cells, red blood cells, hemoglobin, hematocrit) and biochemical (glucose, urea, creatinine, total protein, albumin, ASAT, ALAT) blood parameters of rainbow trout (Oncorhynchus mykiss W.), cultivated in a recirculation system. The fish were divided into 6 groups: one control (C) and five experimental groups in whose food was added phytoextracts of curcumin (EC), paprika (EP), thyme (ET), oregano (EO) and garlic (EG). The inclusion of phytoextracts had no significant effect on growth parameters of fish from EC, EP, ET, EO and EG groups (P>0.05). Statistically significantly lower feed consumption per unit weight gain was observed in EO group vs C (Р<0.05). The phytoextract supplementation had significant influence on some of the haematological (white blood cells, red blood cells, hemoglobin) and biochemical (urea, creatinine, total protein, albumin, ASAT, ALAT) blood parameters of rainbow trout.

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Productive traits, blood biochemical parameters and meat quality of rainbow trout (Oncorhynchus mykiss W.) fed with supplement of nutmeg extract (Myristica fragrans)

Agricultural Science and Technology ◽

10.15547/ast.2020.04.051 ◽

2020 ◽

Vol 12 (4) ◽

pp. 324-330

Author(s):

Ts. Stoev ◽

G. Zhelyazkov

Keyword(s):

Fatty Acid ◽

Rainbow Trout ◽

Weight Gain ◽

Oncorhynchus Mykiss ◽

Sunflower Oil ◽

Biochemical Parameters ◽

Live Weight ◽

Rainbow Trout Oncorhynchus Mykiss ◽

Blood Biochemical ◽

Recirculation System

Abstract. The aim of the present study was to evaluate the effect of the dietary nutmeg extract (Myristica fragrans) supplement on the survival rate, weight gain, feed conversion ratio (FCR), economic efficiency (ECR), blood biochemical parameters, chemical composition and fatty acid profile of rainbow trout (Oncorhynchus mykiss W.), cultivated in a recirculation system. One hundred and sixty rainbow trouts were distributed in two experimental variants, each with two replications with 80 fish in one group. The average initial live weight of trouts from control (C) and experimental (E) groups was 13.43±0.33 g and 13.46±0.29 g, respectively. Fish were reared in concrete tanks with effective volume of 0.8 m3, part of a recirculation system. Trouts were fed „Aqua garant UNI“ extruded feed produced by Garant-Tiernahrung Gesellschaft m.b.H. – Austria, with pellet size of 2 mm. The feed of fish from the experimental group was supplemented with 1% powdered nutmeg extract (P.I.C.Co LTD), by lubricating the pellets with 5 ml sunflower oil/100 g feed. Control rainbow trouts received feed lubricated with the same amount of sunflower oil. Fish from both groups were fed 3 times daily and their ration was 3% of body weight. The experimental period lasted 60 days. The dietary supplementation of rainbow trouts with nutmeg extract had a negative impact on growth performance and economic efficiency of farming of the species. Final live weight and average individual weight gain were lower, and FCR and ECR values were inferior vs controls. The nutmeg extract had also an adverse effect on water content and dry matter of meat from supplemented fish. A positive effect was demonstrated only on meat fat content, which was substantially lower compared to that of control fish. Despite the higher SFA as well as lower UFA, MUFA, PUFA, n-6 and n-3 fatty acid content of trout meat that received nutmeg extract with feed, the PUFA/SFA and n-6/n-3 ratios remained within the favourable range for human nutrition, e.g. >0.4 and <5, respectively.

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