Biorefining of Red Clover ( <i>Trifolium pratense</i> ) Yields a Phytoestrogen-Rich Byproduct with Potent Antiparasitic Activity

Biorefining of grasses and legume forages is carried out commercially to recover feed proteins for monogastric animals. The biorefining produces a fiber-rich pulp byproduct with additional valorization potential. Here, we explored whether pulp products from several biorefined plants could exhibit bioactivity against animal parasites. Among the tested plants, extracts derived from red clover possessed exceptionally high bioactivity against <i>Ascaris suum</i> larvae. GC-MS analysis revealed the antiparasitic compounds to be phytoestrogens, especially biochanin A and to a lesser extent formononetin. Higher concentrations of biochanin A and formononetin were found in biorefined pulp compared with unfractionated plants. These results underscore the dual benefit of biorefining: producing sustainable protein feed and valorizing residues for antiparasitic applications. These findings may offer a potential alternative to synthetic anthelmintics in addressing drug resistance challenges in livestock parasite management. Moreover, they pave the way for cost-effective, ecofriendly feed supplements, promoting circular economy principles in agriculture.