Enhancing performance and fatty acid composition of Nile tilapia (Oreochromis niloticus) from housefly maggot (Musca domestica) feeds
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Abstract
Abstract. Lobina AA, Mkupasi EM. 2020. Enhancing performance and fatty acid composition of Nile tilapia (Oreochromis niloticus) from housefly maggot (Musca domestica) feeds. Bioteknologi 17: 81-89. This study was conducted to compare the effect of three substrates on the yield and composition of housefly maggots (HFM); assessed the growth performance of Oreochromis niloticus (Linnaeus, 1758) fed HFM were mixed with other ingredients, and investigated the enhancement of omega 3 fatty acids composition in the produced O. niloticus. The substrates for HFM production were poultry manure (HFMChick), Lemna species of freshwater macrophytes (HFMLemn), and Eucheuma species of marine macrophytes (HFMEuch). The HFM was then used to formulate eleven diets: nine isonitrogenous diets with 35% crude protein, one diet of 5% fish meal, and the other with soybean meal. Diets were named SBM, FM, HFMChick, HFMLemn, and HFMEuch, denoting soybean meal, fish meal, and HFM cultured on poultry manure, HFM cultured on Lemna species of freshwater macrophyte, and HFM cultured on Eucheuma species of marine macrophyte, respectively. A feeding trial was carried out on triplicate groups of ten fish (1.9-2.2 g) in recirculation aquaculture systems (RAS). The fish were fed up to 5% of their body weight twice daily throughout the experimental period. The effect of inclusion levels of HFM and other diets on fish growth feed utilization and ?-3FAs were determined. A gas chromatography-mass spectrometer (GC-MS) was used to analyze the composition of Omega 3 fatty acids. Results showed that the yields of HFM from poultry manure and Eucheuma species of marine macrophytes (HFMEuch) substrates were significantly higher (P<0.05) than those from Lemna species of freshwater macrophyte. The protein content of HFM from Eucheuma species of macrophyte was significantly higher (P<0.05) than those from poultry manure and Lemna species of freshwater macrophyte. Fish fed on diets containing HFMEuch and FM had significantly higher (P<0.05) growth performance compared to fish fed on HFMChick, HFMLemn, and SBM diets. Thirty-two (32) types of FAs with different saturation levels were detected. The fish-fed HFM cultured on Eucheuma species had the highest composition of FAs (32) compared to others. In conclusion, poultry manure substrates showed better yield results for culturing HFM than other substrates. Eucheuma species can be used to culture HFM as an alternative feed ingredient to improve the performance and composition of ?-3FAs in cultured O. niloticus.