Sustainable Animal Nutrition and Feeding Strategies for Reducing Methane Emissions and Enhancing Feed Digestibility with Encapsulated Black Soldier Fly Larvae Oil

Sustainable feeding strategies incorporating alternative feed ingredients, such as insect-derived oils, play a crucial role in improving nutrient utilization in ruminants while mitigating environmental impact and methane emissions. Black soldier fly larvae oil (BSFLO) has emerged as a promising lipid source; however, its effective utilization requires protection to prevent adverse effects on rumen microbial activity. This study aimed to evaluate the effects of encapsulated BSFLO on rumen fermentation, gas production kinetics, methane estimation, and digestibility using an in vitro approach. A completely randomized design (CRD) with a 2 × 4 (+1) factorial arrangement was employed. The first factor was the type of BSFLO (intact or encapsulated), while the second factor was the product level (2%, 4%, 6%, and 8% of dry matter [DM]), with an additional negative control included. The in vitro analysis revealed that encapsulated BSFLO significantly ( p < 0.05) increased gas production, with the highest value observed at the 2% level. Encapsulated BSFLO enhanced rumen digestibility, with the highest values recorded for the negative control, 2%, and 4% encapsulated BSFLO treatments. Additionally, digestibility in the abomasum was highest for the negative control and the 2% encapsulated BSFLO treatment. Encapsulated BSFLO also significantly ( p < 0.05) reduced methane (CH 4 ) production, with the lowest values observed at 2%, 4%, 6%, and 8% encapsulated BSFLO. Encapsulated BSFLO had no significant effect ( p > 0.05) on total ammonia-nitrogen (NH 3 -N), pH, and protozoal population. Furthermore, total volatile fatty acid (VFA) values were not significantly ( p > 0.05) increased by the inclusion of encapsulated BSFLO. In conclusion, encapsulated BSFLO is a promising feed additive that enhances digestibility and reduces methane emissions, contributing to sustainable animal nutrition. Its potential to lower the environmental impact of ruminant production supports efficient feeding strategies for improved livestock productivity.