EFFECTS OF 17 a-METHYLTESTOSTERONE ON GROWTH PERFORMANCE AND SOME PHYSIOLOGICAL CHANGES OF NILE TILAPIA, OREOCHROMIS NILOTICUS L.) FINGERLLNGS

Abstract

_^ifferent doses of 17 a-methyltestosterone hormone (MT) used as I) growth promoter was administrated to Nile tilapia; Oreochromis niloticus in fishmeal based pelleted diet for 90 days. The obtained results showed that low doses of 0.5, L0 and 2.5 mg MT/kg feed were not effective meanwhile the dose of 5.0 mg/kg was the optimum effective one in promoting significant final weight, weight gain and SGR of Nile tilapia. HSI was insignificantly changed at low MT doses, and slightly increased at high MT doses. Male and female GSI was significantly decreased at high MT doses (10, 20 and 40 mg/kg), while insignificant changes were observed at low doses. Feed intake and FCR were slightly changed at different doses of MT. The higher PER was obtained with moderate MT doses and the least ones were obtained with 20, 40 mg/kg or control. The changes in erythrocyte counts, haemoglobin content, haematecrit value and plasma glucose showed insignificant differences at all treatments. A significant reduction of plasma total protein was observed in fish fed 40 mg MT/kg, whereas it was insignificantly changed with other treatments. in contrast, the highest level in plasma total lipids was obtained at 40 mg MT/kg. In fish plasma, the activity of ALT was the highest with control fish and that fed low doses of 0.5-2.5 mg MT/kg, while the least one was obtained with 40 mg/kg. In contrast, AST activity was significantly increased with high MT doses of 20 and 40 mg/kg, while there were no significant changes among other treatments. The higher 2 Mohammad H. Ahmad et at. activity of alkaline phosphatase (ALP) was obtained at low MT doses (0 to 2.5 mg/kg), after which ALP activities decreased to reach the lowest one at 40 mg/kg. Hepatic ALT and AST activities were increased with increasing MT doses where the maximum ALT and AST activities were obtained at 40 mg/kg, while the minimum ones were obtained at MT doses of 0 to 5 mg/kg. In fish muscle, the activity of ALT and AST showed significant reduction with increasing MT doses where the minimum one was obtained with 40 mg/kg. On the other hand, AST activity was insignificantly changed at all treatments.

Growth, Reproduction and Sex Ratios in Oreochromis Andersonii (Castelnau, 1861) Fed with Varying Levels of 17α-Methyl Testosterone

“…The effect of MT on gonads appears to be complex [27]. In the current experiment, there was no evidence of MT having an effect on the reproductive characteristics of O. andersonii since the GSI, GI and egg size were not significantly different (P>0.05).…”

Comparative study for the production of the male Nile tilapia between inter-specific hybridization and hormonal sex reversal

“…Some authors such as Woo et al (1993) and Ahmad et al (2002) supported the present results. The increase in body weight gain may be attributed to that androgen steroids enhance the release of growth hormone from the pituitary somatotrophs of fish and/or induce the feed digestion and absorption rate, causing increase in body weight (Khalil et al, 2011).…”

Dietary Prebiotics and Probiotics Influence the Growth Performance, Feed Utilisation, and Body Indices of Snakehead (Channa striata) Fingerlings

“…Each fish was individually removed with a small soft towel, dried using tissues, and the weight and length were recorded; fish were subsequently released to their respective tanks, which were filled with clean new water. To analyse growth performance, the conditional factor (CF), relative growth (RG), specific growth rate (SGR), and survival rate (SR) were determined using the formulae described by Austreng (1978), Busacker et al (1990), and Ahmad et al (2002). Moreover, the protein efficiency rate (PER) and food conversion ratio (FCR) were calculated to measure the growth efficiency of the test feeds using the following formulae (Abdel Tawwab et al 2008 Vitamin mix (kg -1 ) = calcium phosphate (monobasic) 397.65 g, calcium lactate 327 g, ferrous sulphate 25 g, magnesium sulphate 137 g, potassium chloride 50 g, sodium chloride 60 gm, potassium iodide 150 mg, copper sulphate 780 mg, manganese oxide 800 mg, cobalt carbonate 100 mg, zinc oxide 1.5 g and sodium selenite 20 g; e NFE = nitrogen free extract (1000-{moisture+protein+lipid+ash+fibre}); f GE = gross energy; measured using bomb calorimeter (Parr 1356 bomb calorimeter).…”