Exhausted olive pomace as a replacement for soybean hulls in corn silage-based diets for late-lactating Holstein cows: Insights from sustainable dairy farming

Abstract This study evaluated the effects of replacing soybean hulls with exhausted olive pomace (EOP) on feed intake, milk production and composition, and rumen fermentation parameters. A cyclical changeover design experiment was used with 4 rumen-fistulated Holstein cows, 3 corn silage-based diets containing 0%, 3% or 6% of EOP (DM basis), and 3 21-d periods. Measurements were taken from d 15 to 21, and rumen contents were sampled on the last day. Diet did not affect feed intake, milk production and composition, or MUN. Ruminal pH, total short-chain fatty acids concentration, and molar proportions of individual acids, were also unaffected by the different dietary treatments. These findings suggest that EOP comprises a sustainable feed resource for late-lactating dairy cows fed corn silage-based diets, supporting circular economy approaches to promote the compound feed industry's resilience, competitiveness, and sustainability.