Background: Insects, particularly those belonging to the order Diptera, offer a promising alternative protein source for poultry with numerous advantages. Among these, Sarcophaga dux (Diptera: Sarcophagidae), a widely distributed global dipteran species, including Saudi Arabia, exhibits potential for waste management. This study was conducted to investigate the nutritional values of both larval and pupal stages of S. dux as well as the feed intake (FI) and the feed conversion ratio (FCR). S. dux flies (&asymp;170 to 200 newly hatched larvae) were reared in standardized laboratory conditions until reaching the pupal stage. 
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Methods: The daily feed intake was calculated for each larvae replicate and FCR was measured on the last day of the 3rd&nbsp;larval instar. Larvae and pupae from each replicate were subject to the proximate analysis, amino acids and minerals. Results indicated a progressive increase in FI throughout the development period, except for the last day of the 3rd&nbsp;larval instar. 
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Result: The FCR demonstrated a higher value comparing to previous study. Furthermore, both larval and pupal stages exhibited high crude protein, lipid content and crude fibre with low dry matter and elevated ash content. The amino acid and mineral contents were also high, with low levels of heavy metals. Notably, the pupal stage displayed superior results in this study. These results may indicate that larvae and pupae of S. dux are promising sources of protein, minerals and potentially other essential nutrients which, in fact, suggest it as a nutritionally valuable food sources for poultry. Upon comparing the larval and pupal stages, it is evident that essential minerals are generally abundant in both stages except for manganese (Mn), which was found to be highest in pupae. However, it is noteworthy that the levels of heavy metals in both stages were low and exhibited no significant difference except for lead (Pb).

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The Immature Stages of Sarcophaga dux (Diptera; Sarcophagidae): A Proposed Nutritional Source for Poultry

Background: Providing ornamental fish (Carassius auratus), with nutritious and sustainable food sources is an increasingly important part of that process. Flesh flies (Sarcophaga spp.) have a high content of nutrient in their larval stage, which make their bodies grow quickly during their larval phase. 
 
Methods: The nutrient composition of Sarcophaga larvae and their effect as a feeding source on C. auratus growth during the process were studied. In a laboratory, Sarcophaga larvae were cultured on shrimp shells and C. auratus fed on Sarcophaga larvae were compared to C. auratus fed on commercial food. 
 
Result: Crude protein content of 52.5% was remarkably high, followed by crude lipid (30.2%), crude fibers (9.8%) and finally crude ash (7.5%). Our results showed also a significant improvement in growth performance of C. auratus fed on Sarcophaga larvae, with a median weight of 25.3 g compared with the control group (17.3 g) by the fourth week, indicating significant advantages for C. auratus fed on Sarcophaga larvae. In this study, Sarcophaga larvae are examined as a sustainable and nutritious source of food for C. auratus fish. Using insect larvae for aquaculture should be further refined and evaluated for long-term benefits and safety.

The Immature Stages of Sarcophaga dux (Diptera; Sarcophagidae): A Proposed Nutritional Source for Poultry

Cultivating Flesh Fly Larvae as a Sustainable Feed Source for the Ornamental Fish (Carassius auratus)