Abstract
Background:
Broiler livestock supports the fulfillment of animal protein in a country where the meat price is affordable for the wider population. However, its progress faces numerous challenges, with colibacillosis, induced by APEC, being a significant concern due to its detrimental impact on production levels, as evidenced by elevated morbidity and mortality rates. Exploring natural antibacterial substances, such as ant nest extracts, presents promising avenues for combating APEC.

Aim:
This study investigated the potential of Myrmecodia sp. extract as a natural feed additive to improve performance and immune responses in APEC-challenged broiler chickens.

Methods:
The effects of varying concentrations of Myrmecodia extract (15% and 30%) at 0.1% concentration and infusions (1% and 2%) were evaluated against a zinc bacitracin control using a completely randomized design with seven treatments and four replications. Growth performance indicators, including feed intake, total body weight, feed conversion ratio (FCR), feed efficiency, and immune markers (leukocytes, lymphocytes, monocytes, granulocytes, erythrocytes, hemoglobin, hematocrit, platelets, malondialdehyde, and superoxide dismutase levels) were measured.

Results:
Results showed that 15% extract improved FCR by 1.47%, while 30% extract further boosted feed intake and weight gain. Infusion treatments also demonstrated positive effects: the 20 ml infusion improved FCR and stabilized leukocyte and platelet counts, while the 10 ml infusion enhanced overall performance, reduced blood urea nitrogen (BUN) levels, and positively impacted lipid profiles.

Conclusion:
Myrmecodia sp. has the potential to serve as a natural alternative to antibiotic growth promoters in broiler production. However, these results should be interpreted with caution, and further confirmation is required.

Key words: Myrmecodia sp.; Broiler; Feed additive; Antibiotic growth promoter.