Immune Status, Reproductive Potential, Caecal Microbial and Fermentative Characteristics of Rabbits Supplemented Rolfe (Daniellia Oliveri) Leaf Extract Essential Oil Based Diet

This study investigated the effects of essential oil extracted from Daniellia oliveri leaf (DOLE) on immune function, oxidative stress markers, semen quality, and caecal microbial and fermentation characteristics in male rabbits.Animals were randomly assigned to three dietary treatments: a control group fed a basal diet, and two test groups receiving the basal diet supplemented with DOLE at two different inclusion levels.Blood, semen, and caecal samples were collected and analyzed at the end of the trial.Rabbits supplemented with DOLE showed improved immune responses, as indicated by higher levels of immunoglobulins and antioxidant enzymes than the control group.Levels of oxidative stress markers, such as malondialdehyde and cortisol, were significantly reduced in DOLE-supplemented groups.Semen characteristics-including ejaculatory volume, motility, and sperm concentrationwere enhanced with DOLE supplementation, while sperm abnormalities and reaction time were lower compared to the control.Semen color and pH remained consistent across all groups.Microbial analysis revealed a reduction in harmful bacteria, such as Escherichia coli, coliforms, and Streptococcus species, in rabbits fed DOLEsupplemented diets, alongside an increased beneficial Lactobacillus species.Caecal pH remained stable across treatments.Ammonia nitrogen levels were reduced in rabbits receiving the higher dose of DOLE.Additionally, total volatile fatty acids increased with DOLE supplementation, while the concentrations of acetic acid was highest in the control group, the butyric, and propionic acids showed significant increase in animals supplemented DOLE.In conclusion, DOLE supplementation enhanced immune function, mitigated oxidative stress, improved reproductive traits, and positively influenced gut microbial ecology in rabbits.The higher inclusion level of DOLE demonstrated the most pronounced benefits, suggesting its potential as an effective natural dietary additive for improving overall health and productivity in small mammals.