Dispersion of antibiotic in livestock farming represents a health concern worldwide, contributing to the spread of antimicrobial resistant bacteria through animals, the environment, and humans. Phenolic compounds could be alternatives to antibiotics, once drawbacks such as low water solubility, bioavailability, and reduced stability are overcome. Although nano- or microsized formulations could respond to these shortcomings they do not represent cost-effective options. Here, three phenolic compounds, obtained from wood processing manufacturers, were characterized, revealing suitable features such as antioxidant activity, size, and chemical and colloidal stability for in-field applications. The Minimum Inhibitory Concentration (MIC) of these colloidal suspensions was measured against six bacterial strains isolated from livestock. These particles showed different inhibition behaviors: Colloidal chestnut was effective against one of the most threatening antibiotic resistant pathogens such as S. aureus but was ineffective toward E. coli. On the other hand, colloidal pine showed a weak effect on S. aureus but specificity toward E. coli. The present proof-of-concept points at colloidal polyphenols as valuable alternatives for antimicrobial substitutes in the livestock context.