Copaiba oleoresin as a substitute for sodium lasalocid in high-concentrate diets for lambs: growth performance, ingestive behavior, and metabolic and ruminal parameters.

backgroundThe indiscriminate and excessive use of ionophore additives has been associated with the emergence of multi-resistant pathogenic strains and the global spread of antibiotic resistance, raising serious public health concerns. Thus, plant biocompounds have been the focus of several studies aiming to replace ionophore additives in ruminant feeding without negatively impacting animal productivity. This study aimed to evaluate the effects of using copaiba oleoresin (CO) (Copaifera reticulata) as a substitute for sodium lasalocid (LAS) in high-concentrate diets for feedlot-finished lambs, analyzing intake, growth performance, digestibility, ingestive behavior, and metabolic and ruminal parameters.

resultsSodium lasalocid treatment resulted in higher dry matter intake than the 1 mL CO dose (CO-1.0) (P = 0.02) but did not differ significantly from the 0.5 mL CO dose (CO-0.5). Similarly, LAS resulted in higher neutral detergent fiber rumination efficiency (32.17) then CO-1.0 (24.60) (P < 0.01), but did not differ from CO-0.5 (28.23). In the LAS group, ruminal pH (6.41) was slightly lower than the values observed in CO-0.5 (6.77) and CO-1.0 (6.84). The total concentration of short-chain fatty acids and ammonia nitrogen decreased (P < 0.05) with the inclusion of CO-0.5 and CO-1.0.

conclusionThe use of copaiba oleoresin altered intake and ruminal parameters but did not affect growth performance; it therefore has the potential to be utilized in diets for feedlot-finished lambs. © 2026 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.