Diet inclusion of housefly larvae and frass supplemented by Rayabold (enzyme and probiotic) on performance of laying hens and egg quality

This study investigated the effects of dietary housefly larvae and frass (HFLF), with or without a multi-component supplement (Rayabold), on the performance, egg quality, and blood biochemical parameters of Lohmann LSL-Lite laying hens. A total of 192 hens, aged 56 weeks, were assigned to a 10-week feeding trial using a 4 × 2 factorial design with four HFLF inclusion levels (0 %, 5 %, 10 %, and 15 %) and two Rayabold levels (0 % and 0.05 %). A significant interaction was observed for feed intake (FI) (P = 0.0001), with hens fed 10 % and 15 % HFLF consuming less feed than those on the control or 5 % diets. Rayabold further reduced FI at higher HFLF levels. Egg production (EP) improved significantly with 10 % and 15 % HFLF (P = 0.024), while egg weight (EW) peaked at 5 % HFLF (P = 0.003) and was further enhanced by Rayabold (P = 0.008). Both HFLF and Rayabold improved feed conversion ratio (FCR), protein efficiency ratio (PER), and energy efficiency ratio (EER) (P = 0.0001), with the 15 % HFLF diet yielding the most favorable values. In terms of egg quality, higher HFLF levels (10 % and 15 %) reduced eggshell thickness (P = 0.002), while Rayabold increased it (P = 0.0007). Haugh unit values were elevated in the 10 % and 15 % HFLF groups (P = 0.043). Regarding blood parameters, 10 % HFLF lowered glucose (P = 0.0007), and both 10 % and 15 % HFLF increased cholesterol (P = 0.001), with Rayabold further elevating it (P = 0.030). Triglycerides were reduced by both 10 % HFLF and Rayabold (P = 0.050 and P = 0.0001, respectively). HFLF decreased AST (P = 0.0001) and increased albumin (P = 0.006). Complex interactions were noted for ALT and ALP (P = 0.0003 and P = 0.0001), with Rayabold mitigating the ALT increase seen at 5 % HFLF, and all treatments significantly lowering ALP compared to control. These findings support HFLF, particularly at 10-15 %, as a promising poultry feed ingredient for improving productivity and modulating physiological responses.