Replacing hexane by 2-methyloxolane for defatting soybean meal does not impair fattening performance of beef cattle supplemented with methionine
Abstract
Chemical fat extraction for producing soybean meal (SBM) uses solvents like extraction-grade hexane (Hex).
Concerns over health risks from n-hexane residues have motivated the exploration of alternatives like 2-methyloxolane
(2-meOx), a bio-based solvent derived from agricultural by-products. However, differences in processing
techniques between Hex and 2-meOx SBM may lead to varying nutritive values, potentially impacting
animal performances. The aim of this study was to evaluate the performance of beef cattle fed grass silage diets
with 2-meOx compared to hexane-extracted SBM, with or without supplementation of rumen-protected methionine
(RPM). Thirty-six young Charolais bulls (248 ± 21.7 days) were studied during three consecutive 70d-feed
efficiency tests until slaughter. Treatments resulted from a factorial design crossing two types of SBM (Hex vs
2-meOx) with 2 levels of RPM (supplemented or not). DM intake did not differ significantly among the four
treatments for any of the three 70-day efficiency tests (P>0.05). Diets supplemented with RPM promoted higher
average daily gain and feed conversion efficiency during the initial 70-day feed efficiency test, particularly in diets
containing 2-meOx (SBM x RPM interaction; P≤0.02). Additionally, carcass weight, whole-body protein deposition,
and nitrogen use efficiency increased with RPM supplementation, especially in diets containing 2-meOx
(SBM x RPM interaction; P≤0.005). Our results highlight the potential of using 2-meOx as a bio-based solvent for
SBM production in beef cattle diets but suggest a higher methionine deficit compared to Hex SBM.