In this study, we compared the digestibility levels and in vitro fermentation parameters of total mixed rations (TMRs) containing 20% and 40% defatted black soldier fly (Hermetia illucens) larvae (BSF) as a substitute for soybean meal (SBM) in the basal ration (60% roughage/40% concentrated feed) of dairy cows. We evaluated the volatile fatty acid (VFA), total gas production, methane emission, ammonia, pH, carbon dioxide, in vitro dry matter digestibility (IVDMD), and neutral detergent fiber digestibility (IVNDFD) of the TMR0 (basal), TMR20 (20% BSF included), and TMR40 (40% BSF included) diets at the end of 24 and 48 h of incubation. Significantly lower levels of ammonia formation were found in the TMR20 and TMR40 groups at 24 and 48 h (p < 0.001). An increase in total VFA levels was observed in the TMR0 group at 24 h (p < 0.001). The highest IVDMD was determined in TMR20 and TMR40 at 24 h. The highest IVNDFD value was observed in TMR20 at 24 h and in TMR40 at 48 h. The substitution of 20% and 40% of SBM with BSF positively affected IVDMD and IVNDFD (p < 0.001). TMR20 and TMR40 had the highest cumulative gas production at 48 h of incubation (p < 0.05). In conclusion, the use of BSF had a positive impact on digestibility and in vitro rumen fermentation. Therefore, we recommend the use of BSF in formulating dairy cow rations.

This study evaluated the effects of partially or fully replacing poultry fat with black soldier fly larvae (BSFL) fat on faecal parameters, blood biochemistry, immune responses, nutrient digestibility, food preference, and lipid oxidation in dogs. A total of 18 adult Golden Retriever dogs (6 dogs per diet group) were subjected to a digestibility trial for 30 days. Three experimental diets were formulated: a control diet (6% poultry fat), BSF3 (3% poultry fat +3% BSF larvae fat), and BSF6 (6% BSF larvae fat). Serum biochemical parameters, including blood urea nitrogen, creatinine, AST, ALT, glucose, cholesterol, triglycerides, total protein, and immunoglobulin levels (IgE and IgG), were analysed from blood samples collected from all dogs. Faecal consistency scores were recorded over 5 days, and faecal pH, ammonia nitrogen (ammonia-N), short-chain fatty acids (SCFAs), and branched-chain fatty acid (BCFA) concentrations were determined during the final three days of the digestibility trial. Seven days after the digestibility trial, a modified two-bowl preference test was conducted over four days using 20 dogs to assess the palatability of the control and BSF6 diets. Lipid oxidation in the diets was evaluated by measuring thiobarbituric acid reactive substances (TBARSs, mg MDA/kg) at baseline (day 0) and after 2, 4, 7, and 10 months of storage at ambient temperature (23–25 °C). BSF6 exhibited the lowest dry matter and organic matter digestibility percentages (p < 0.05). Protein digestibility was reduced in both BSF3 and BSF6, while ether extract digestibility was significantly lower in BSF6 compared to the control diet (p < 0.05). The replacement of poultry fat with BSF larvae fat had no significant effect on serum biochemical parameters or IgE and IgG levels (p > 0.05). Faecal acetic acid concentrations were higher in the control group compared to BSF3 and BSF6, whereas faecal valeric acid concentrations were lower in the control group than in the BSF3 and BSF6 groups (p < 0.05). Although faecal pH and consistency scores were not significantly influenced by the dietary fat source, the total SCFA concentrations in faeces decreased with the substitution of BSF larvae fat (p < 0.05). Furthermore, the dogs demonstrated a higher preference rate for the control diet over the BSF6 diet (p < 0.05). In conclusion, the inclusion of BSF larvae fat in dry dog food formulations reduced nutrient digestibility and palatability but had no adverse effects on the health status of the dogs.

The influence of the physical and chemical composition of corn distillers dried grains with solubles on its flowability was evaluated in the current study. The samples were evaluated for angle of repose, compressibility, Hausner ratio, tapped density, bulk density, mean bulk density, colour and nutrient content. PROC CORR and REG procedures were used to determine correlations. The ether extract was negatively correlated with crude protein and redness (a*), while crude protein was negatively correlated with yellowness (b*). Acid detergent fibre and neutral detergent fibre were negatively correlated with a* and positively correlated with lightness (L*), respectively. Compressibility showed a negative correlation with bulk density. Bulk density, tapped density and mean bulk density did not impact the angle of repose. The angle of repose was positively correlated with the compressibility and Hausner ratio. Apart from the correlation between acid detergent fibre and tapped density, the angle of repose and other physical parameters were not affected by the nutrient composition of the distillers dried grains with solubles samples. In conclusion, the results of this study indicate that nutrient composition has little influence over the flowability of distillers dried grains with solubles but compressibility and the Hausner ratio can be used to predict the potential flow characteristics of corn distillers dried grains with solubles.