A new long-term study has found that plant-based compounds derived from herbs such as oregano and rosemary could offer a viable alternative to antibiotics in pig production, with lasting benefits for animal health and growth.
The research, published in Animal Research and One Health, examined how phytochemicals—natural bioactive compounds extracted from plants—affect gut health and growth performance in pigs across their full production cycle.
Long-term approach reveals hidden benefits
Unlike many previous studies that focus only on early-life stages, researchers conducted a longitudinal trial tracking pigs from weaning through to finishing. Piglets were divided into four groups: a control group, a group receiving antibiotics and zinc, and two groups fed diets supplemented with phytochemical blends containing Lippia origanoides and Rosmarinus officinalis.
Growth performance and gut microbiome changes were monitored across three key phases—nursery, growing, and finishing—allowing scientists to assess both immediate and long-term effects.
The study found that while short-term differences during early growth were limited, pigs fed phytochemical supplements showed improved outcomes later in life. These included better growth performance and enhanced gut health linked to more diverse microbial populations.
Gut microbiome key to performance
Researchers attribute the improved performance to the role of the gut microbiome in nutrient absorption and immune function. The phytochemical treatments helped preserve microbial diversity in the pigs’ digestive systems, which in turn improved nutrient utilization efficiency.
This is significant because antibiotic growth promoters—commonly used in livestock—are increasingly restricted worldwide due to concerns over antimicrobial resistance. The findings suggest plant-based alternatives could help maintain productivity without contributing to resistance risks.
Implications for sustainable livestock production
The study adds to growing evidence supporting phytochemicals as sustainable feed additives in animal agriculture. By demonstrating lifetime benefits rather than short-term gains, the research highlights the importance of evaluating feed interventions over the entire production cycle.
Scientists say the results could help farmers transition away from antibiotics while maintaining herd health and performance, a key goal in modern livestock systems.
Longitudinal Modulation of the Gut Microbiome and Growth Performance by Phytochemicals as Antibiotic Alternatives in Swine Production. Animal Research and One Health (2026). Available at: Read the full study
