King Palm (Archontophoenix alexandrae) Byproduct Valorization by Lentinula edodes Colonization for Ruminant’s Diet: In Vitro Effects on Ruminal Fermentation and Greenhouse Gases Emissions

This study aimed to assess the effects of a new high-value bioproduct from the King palm byproduct valorization on in vitro ruminal fermentation variables.

The bioproduct was developed through solid-state fermentation of King-palm’s shells supplemented with soybean meal and cassava bagasse, carried out by Lentinula edodes. Three in vitro experiments were performed to evaluate the in vitro gas production profiles (GP), enteric methane (CH₄) and carbon dioxide (CO₂) production, volatile fatty acids (VFA), and ammonia–nitrogen (NH₃-N), comparing the bioproduct with corn silage (Exp. 1), brachiaria hay, and sugarcane (in nature) (Exp. 2), and on the replacement of corn silage in beef cattle finishing diets (0%, 33%, 66%, and 100%) (Exp. 3).

For Exp. 1 and 2, the first 24 h of total GP bioproduct had the lowest value compared to corn silage, brachiaria hay, and sugarcane, as well as for 48 h and 72 h. The in vitro organic matter digestibility (IVOMD), production of CH₄ and CO₂, and total VFA concentrations were lower for the bioproduct than corn silage, brachiaria hay, and sugarcane. Bioproduct concentrations (Exp. 3) did not affect total GP at 24 h and 48 h incubations, IVOMD, CH_4, and CO₂ production, pH, total VFA concentration, and NH₃-N concentration. The NDF degradation rate decreased with the bioproduct inclusion concentrations.

This study highlighted a promising nutrient source and bioactive compound reservoir for cattle diets, demonstrating efficacy in vitro ruminal fermentation. This agro-industry and livestock sector integration could promote a circular bioeconomy, enhancing sustainability.