Conversion of Mixtures of Soybean Curd Residue and Kitchen Waste by Black Soldier Fly Larvae (Hermetia illucens L.)

The production of insect biomass from organic waste is a major challenge in terms of reducing the environmental impacts of waste and maintaining feed and food security. The feasibility of the co-conversion of soybean curd residue (SCR) and kitchen waste (KW) to breed black soldier fly (BSF, Hermetia illucens) larvae was evaluated so as to enhance biomass conversion efficiency and supply animal feed and allow it to be used in biodiesel production. Co-digestion was found to significantly increase larval yield, bioconversion rate, and bioaccumulation of lipid. Partial least squares regression showed that the conversion of 30% SCR with 70% KW is an appropriate proportion. The appropriate performance parameters of BSF were: survival rate (98.75%), prepupal rate (88.61%), larval biomass (30.32 g fresh and 11.38 g dry mass), bioconversion rate (18.45%), efficiency conversion of ingested food (ECI) (28.30%), and FCR (2.51). Our results show that conversion of mixtures (e.g., SCR with KW) by BSF larvae (BSFL) could play an important role in various organic materials management.

Growth Performance, Waste Reduction Efficiency and Nutritional Composition of Black Soldier Fly (Hermetia illucens) Larvae and Prepupae Reared on Coconut Endosperm and Soybean Curd Residue with or without Supplementation

Black soldier fly (BSF, Hermetia illucens) larvae are considered as insects with a high potential to convert organic waste into high-value products. The objective of this study was to investigate the growth performance, waste reduction efficiency, and nutritional composition of BSF reared on different ratios of coconut endosperm (C) and soybean curd residue (S), with or without supplementation, compared to standard diets (Gainesville: G and starter chicken diet: CK). Seven-day-old larvae were randomly divided into eight experimental groups (G, CK, and three different ratios of C and S with or without supplementation) with three replicates with an equal weight of larvae. The supplement contained calcium, phosphorus, amino acids, and a mineral–vitamin premix which was formulated to correlate with CK. Each replicate was terminated, measured, and evaluated when 40% of larvae had reached prepupal stage. The highest larval weight gain was presented in BSF fed CK, followed by those fed coconut endosperm and soybean curd residue at a ratio of 20 : 80 (C20S80), and coconut endosperm and soybean curd residue at a ratio of 50 : 50 (C50S50) without supplementation (numbers after C and S represent their percentage in the formulation; p < 0.001). Harvesting was delayed in the BSF fed C80S20 with and without supplementation (p < 0.001). The number of total larvae and prepupae was not significantly different between groups (p > 0.05). The greatest waste reduction efficiency was observed in the G, C50S50, and C20S80 groups without supplementation (p < 0.001). All groups with supplementation had a higher proportion of ash in both larvae and prepupae compared to non-supplemented groups (p < 0.001), but lower growth performance. The highest percentage of crude protein in larvae was presented in the Gainesville and C20S80 groups followed by the CK and C50S50 groups (p < 0.001). Equal proportions of C and S without supplementation are suggested as a rearing substrate. However, growth performance was lower than for CK; therefore, further studies could investigate cost-efficient techniques to promote this parameter.

Anaerobic Digestion of Corn Stover for Improved Biomethane Yield: Effect of Organic Nitrogen Sources (Soybean Curd Residue and Fish Waste)

The present study investigated the effect of organic nitrogen sources, soybean curd residue (SCR), and fish meal (FW) on the anaerobic digestion of corn stover for biomethane production. The bioreactors were seeded with the corn stover (corn cob and corn sheath), soybean curd residue (SCR), and fish waste (FW) at different combinations: (CC/SCR), (CC/FW), (CS/SCR) and (CS/FW), including CC and CS alone. The fermentation was for 31 days under mesophilic conditions. Characteristics of the substrates indicate that CC and CS are good carbon and energy sources, but low in nitrogen content. Conversely, SCR and FW are rich nitrogen sources, with low organic carbon content. There was a remarkable increase in biogas production in all treatments, except CC/SCR 75:25 and CC/SCR 85:15 in which inhibitory effect was observed. The highest percentage increase (138%) in biogas was recorded in CS/SCR 85:15 (2.86 dm3), and the least was CC/FW 75:25 with 1.49 dm3 (24.18% increase). Significant difference (P ≤ 0.05) in biogas yield was in the following: CC/SCR 50:50, CC/FW 50:50, CS/SCR 85:15, CS/FW 50:50, and CS/FW 75:25. The composition of the biogas revealed that the treatment improved biogas production as well as biomethane content, the highest being 69.44% in CS/SCR 85:15. Regression analysis of cumulative biogas yield as a function of time (t) in the different treatments that had a significant difference in biogas yield showed a good correlation between biogas yield (GY) and time (t). Improving the biodegradability of lignocellulosic wastes could lead to a boost in the development of anaerobic digestion and biogas production technology. To improve their biodegradability during anaerobic digestion, both pre-treatments and supplementation have vital roles to play.

The Effect of Increasing Neutral Detergent Fiber Level through Different Fiber Feed Ingredients throughout the Gestation of Sows

The purpose of this study was to determine the effect of increasing dietary neutral detergent fiber (NDF) levels on pregnant sows, and to select the best feed ingredients based on reproductive performance, plasma biochemistry parameters, colostrum and milk composition, and nutrient digestibility. Seventy-two multiparous sows were randomly allotted to six dietary treatment groups (n = 12). The feeding of chicory meal (CM), wheat bran (WB), corn gluten, and rice bran meal (RBM) increased the average weaning weight of piglets compared with the control (CON) group (p < 0.05). Supplementation with CG diet increased the sow BW, weight gain, and back fat thickness compared with WB and RBM on day 107 of gestation (p < 0.05). Furthermore, Supplementation with CG diet resulted in lower plasma urea nitrogen (PUN) and higher total protein (TP) concentrations in plasma (p < 0.05). Feeding CM diet and soybean curd residue (SCR) diet reduced the total protein and globulin, and supplementation with CM diet significantly increased the PUN (p < 0.05). The apparent total tract digestibility (ATTD) of crude protein (CP), crude fat (EE), calcium (Ca), phosphorus (P), neutral detergent fiber (NDF), and acid detergent fiber (ADF) were decreased following the addition of CM, WB, or SCR to the diets (p < 0.05). The ATTD of NDF and ADF were significantly increased in the CG group (p < 0.05). In conclusion, the feeding of CG diet to sows have an excellent effect.