The present study aimed to evaluate the effect of adding rosemary and pennyroyal dietary supplementation on performance, microbial population, and intestinal morphology. 160 female Japanese quails were assigned to various dietary treatment groups with four replications (0% rosemary or pennyroyal, 1.5% rosemary, 1.5% pennyroyal, and 1.5% mixture of rosemary and pennyroyal). The results showed that neither pennyroyal nor rosemary powder significantly affected feed intake. However, a significant decrease in feed intake was observed in the group that received a mixture of pennyroyal and rosemary powder (p < .05). Also, feed conversion ratio was higher in all treatment groups compared to the control group (p < .05). Treatments had no effect on body weight gain. The weight of quail eggs increased (p < .05) with supplementation of their diet with a mixture of pennyroyal and rosemary powder. Although the experimental treatments did not affect shell weight, adding pennyroyal and rosemary powder to the diet increased albumin weight, yolk weight, and eggshell thickness compared to the control group. Moreover, the study demonstrated that using pennyroyal powder, rosemary powder, and a mixture of pennyroyal and rosemary powder significantly (p < .05) decreased the intestinal coliform population. A significant (p < .05) increase in intestinal villi length was observed in all treatment groups. Results indicated that the addition of rosemary and pennyroyal to the diet of laying quail has a positive impact on some productive characteristics.
Cite this article as: Seifi, S., & Marzban Abbasabadi, B. (2025). Effects of rosemary (rosmarinus officinalis L.) and pennyroyal (mentha pulegium L.) on performance, microbial population, and intestinal histomorphometry of laying Japanese quails. Acta Veterinaria Eurasia, 51, 0094, doi: 10.5152/actavet.2025.24094.