Effects of oxygen concentration and body weight on maximum feed intake, growth and hematological parameters of Nile tilapia, Oreochromis niloticus

Although fumonisins are identified as responsible for alterations in weight gain, little information is available on their effects on expression of growth-related genes, especially for Nile tilapia (Oreochromis niloticus) fingerlings. In this study, Nile tilapia fingerlings were treated with increasing levels of fumonisin B1 (FB1) and fumonisin B2 (FB2) (diets of 0, 20, 40, and 60 mg/kg) to evaluate their effects on weight gain (WG), feed intake (FI), feed efficiency (FE), growth hormone receptor (GHR) and insulin growth factor 1 (IGF-1) mRNA expression in liver of this fish. All variables were evaluated at 15 and 30 days of treatment. Diet containing 0 mg fumonisin/kg was used as control treatment. Treatment with 20, 40, and 60 mg fumonisin/kg of diet significantly reduced WG (P<0.0001) and FE (P<0.0001), while GHR and IGF-1 mRNA expression was reduced both at 15 and 30 days of treatment. Feed intake was not affected by diets in any of the evaluated periods. These results indicate that fumonisins (FB1 + FB2) affect the growth of Nile tilapia fingerlings through mechanisms that involve reduction of GHR and IGF-1 expression.

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Effect of feeding frequency on water quality, growth, and hematological parameters of Nile tilapia Oreochromis niloticus reared using biofloc technology

Journal of Applied Aquaculture ◽

10.1080/10454438.2020.1715909 ◽

2020 ◽

pp. 1-15

Author(s):

Hamilton Hisano ◽

Victor Rossi Pinheiro ◽

Marcos Eliseu Losekann ◽

Mariana Silveira Guerra Moura e Silva

Keyword(s):

Water Quality ◽

Oreochromis Niloticus ◽

Nile Tilapia ◽

Hematological Parameters ◽

Feeding Frequency ◽

Nile Tilapia Oreochromis Niloticus ◽

Biofloc Technology ◽

Effect Of Feeding

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Optimal Replacement of Fish Meal Protein by Stick Water in Diet of Sex-Reversed Nile Tilapia (Oreochromis niloticus)

Animals ◽

10.3390/ani9080521 ◽

2019 ◽

Vol 9 (8) ◽

pp. 521

Author(s):

Uraiwan Wattanakul ◽

Wattana Wattanakul ◽

Karun Thongprajukaew

Keyword(s):

Oreochromis Niloticus ◽

Nile Tilapia ◽

Fish Meal ◽

Specific Activity ◽

Hematological Parameters ◽

Dietary Treatment ◽

Normal Liver ◽

Carcass Quality ◽

Liver Histopathology ◽

Nile Tilapia Oreochromis Niloticus

The effects of replacing fish meal (FM) protein with stick water (SW) were investigated during the market stage of sex-reversed Nile tilapia, Oreochromis niloticus (18.49 ± 0.31 g initial body weight). The FM protein was replaced with SW for 10% (10SW), 20% (20SW), 30% (30SW) and 50% (50SW) of the FM. The completely randomized design was conducted in outdoor 15 floating baskets (1.5 × 1.5 × 2 m), comprising three replications with 50 fish each, over an 8 month trial. At the end of the experiment, no differences in survival, growth performance or feed utilization were observed across the dietary treatments (p > 0.05). A significant change in lipase-specific activity was caused by the replacement, without changes to trypsin, chymotrypsin or amylase activities. The fish in all dietary groups exhibited normal liver histopathology, but the fish fed a diet containing SW showed higher numbers of cells accumulating lipids as compared to fish fed the baseline 0SW dietary treatment. Hematological parameters were similar across the five dietary groups. Only fish fed the 20SW diet had superior carcass quality compared to the baseline 0SW group, in terms of crude protein and lipids, but lower or higher replacement levels had negative effects on carcass quality. Findings from the current study support the replacement of FM protein with SW at a level of 20% in the diet of sex-reversed Nile tilapia reared to the market stage. Higher replacement levels might be possible with the supplementation of fatty acids.

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