Substitution of feed protein source with defatted black soldier fly larvae meal (BSFM) has been evaluated intensively in poultry, but information about full-fatted BSFM is still very limited. The aim of the present study was to investigate the effect of dietary low inclusion of full-fatted BSFM on the growth performance, plasma antioxidant ability, nutrient digestibility, and gut health of layer chickens during 1–42 days of age. A total of 480 female 1-day-old Hy-Line Brown chickens were divided into four dietary treatments, with the inclusion of 0, 3, 6, and 9% of full-fatted BSFM. Each treatment included six replicates and 20 birds per replicate. As dietary full-fatted BSFM inclusion levels increased, there was a quadratic increase in final weight and average daily gain and a quadratic decrease in feed/gain ratio. Dietary full-fatted BSFM inclusion levels increased the digestibility of crude protein and ether extract quadratically as well as ileum mucosal sIgA concentration linearly, but these had no effect on intestinal morphology. Additionally, an increase in dietary full-fatted BSFM inclusion levels resulted in a linear increase in glutathione peroxidase and total superoxide dismutase activities and a linear decrease in malondialdehyde content in plasma. The encouraging results of the improvement of growth performance, nutrient digestibility, antioxidant ability, and gut health parameters suggested that partially full-fatted BSFM inclusion can be suitable protein ingredients for layer chickens' diets at the starter period.

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The black soldier fly (Hermetia illucens) larvae meal (BSFM) has been widely applied in aquaculture production due to its rich nutritional value, easy availability, and renewability. However, to our knowledge, it has not been used in the diets for turtles. Here, we evaluated the acceptability of partial substitution of fish meal (FM) with defatted BSFM in the diets of juvenile Chinese soft-shelled turtles (Pelodiscus sinensis). A total of 225 juvenile turtles were randomly divided into D1, D2, D3, D4, and D5 groups, which were fed with BSFM replacing 0, 5%, 10%, 15%, and 20% FM, respectively, for 70 days. The results showed that growth performances of groups D2 and D3 were not significantly different ( P > 0.05 ) from that of group D1, whereas the growth performance compromised ( P < 0.05 ) in groups D4 and D5. The activity of serum alkaline phosphatase was higher ( P < 0.05 ) in group D3 relative to other groups, while alanine aminotransferase and aspartate aminotransferase activities were higher ( P < 0.05 ) in group D4 when compared with groups D1, D2, and D3. Liver lysozyme activity and malonaldehyde level were significantly higher ( P < 0.05 ) in group D1 relative to other groups, whereas total antioxidant capacity activity showed the opposite trend ( P < 0.05 ). The activities of hepatic total superoxide dismutase and glutathione peroxidase displayed a linear elevation ( P = 0.011 and P < 0.001 , respectively) from groups D1 to D3. Intestinal amylase and protease activities linearly increased ( P < 0.001 ) with increasing BSFM levels, while intestinal lipase activity showed a quadratic increase and then a decrease with increasing BSFM levels ( P = 0.011 ). Muscle crude protein and fat contents increased ( P < 0.05 ) in group D3 when compared with groups D1 and D2. Muscle phenylalanine, glutamic, tryptophan, and arginine levels increased in group D1 in comparison with the other groups ( P < 0.05 ), whereas the opposite was true for isoleucine and proline levels. The broken-line analysis based on specific growth rate estimated that the optimal level for replacing dietary FM with BSFM is 5.0%, which could elicit benefits on both the growth performance and physiological health condition of the juvenile Chinese soft-shelled turtles.

A lipidomics approach based on liquid chromatography–tandem mass spectrometry (LC-MS) was applied to analyze the molecular-level mechanism of lipid deposition in Hermetia illucens ( H. illucens ) larvae fed food waste (FW) at different days of age. The H. illucens larvae reared on FW substrates generally became larger, heavier, and fatter at 5–15 d of age. A large amount of glycerolipids (GL) were deposited, while glycerophospholipids (GP), sphingolipids, and derivatized lipids became relatively less abundant during the growth stage of the larvae. Forty-three subclasses of 3,205 lipid molecules were identified in larvae, and 139 lipids (79 upregulated and 60 downregulated during larval growth and development) were identified as potential biomarkers (variable importance in projection > 1; P < 0.05). The differential lipids were mainly enriched in 19 metabolic pathways, of which 9 metabolic pathways related to lipids, including GL and GP metabolisms. The results demonstrate that the lipid composition and mechanisms changed during the growth and development stage of H. illucens larvae. To the best of our knowledge, this is the first work exploring the molecular-level mechanism of lipid deposition during the growth and development stage of H. illucens larvae. The findings provide novel information for determining and utilizing the nutritional value of H. illucens larvae.

The aim of the present study was to investigate the effects of dietary supplementation with different doses of rosmarinic acid (RA) on the growth performance, serum biochemical indices, liver antioxidant activity, and muscle nutritional component of broiler chickens during 1–20 days of age. A total of 1000 1-day-old Cobb 500 white-feathered broilers were divided into five groups. Each group included four replicates and 50 birds per replicate. The control group was the basic fodder group fed with a basal diet. The experimental groups included four levels of RA (100, 200, 300, and 400 mg/kg RA added to the basal diet, respectively). The results showed that a quadratic increase in final body weight (BW) and average daily gain (ADG) and a quadratic decrease in the feed/gain (F/G) ratio were observed with increasing dietary RA levels. At 200 mg/kg RA supplementation, growth performance was significantly improved. Moreover, under this RA treatment, the highest levels of total protein and globulin were detected in the serum, the activities of total superoxide dismutase and catalase in the liver of broilers were significantly increased, and the malondialdehyde content was significantly decreased, indicating a higher antioxidant capacity of the liver when 200 mg/kg RA was added to the basal diet. The flavor of the muscle meat was improved by dietary supplementation with 200 mg/kg RA. Therefore, adding 200 mg/kg of RA to the diet could significantly improve the growth performance of broilers, improve liver antioxidant capacity, and improve muscle quality, etc. The addition of RA to broiler feed as a natural antioxidant has great prospects.