eng Rovedar Farm Animal Health and Nutrition 2980-7905 2025-03-24 4 1 1 5 10.58803/fahn.v4i1.65 67 I Made Bagi Rate 0 https://orcid.org/0009-0007-1738-8418 Ni Ketut Suwiti 1 https://orcid.org/0000-0002-7696-3773 Ida Bagus Kade Suardana 2 https://orcid.org/0009-0008-5415-9988 I Nengah Kerta Besung 2 https://orcid.org/0000-0002-5285-592X Master of Veterinary Medicine Student, Udayana University, Denpasar 80234, Bali, Indonesia Department of Veterinary Basic Science, Faculty of Veterinary Medicine, Udayana University, Denpasar 80234, Bali, Indonesia Department of Veterinary Medicine, Faculty of Veterinary Medicine, Udayana University, Denpasar 80234, Bali, Indonesia Introduction:  Sumbawa horses are valued for their cultural, economic, and functional roles in Indonesia. Sumbawa horses are traditionally raised under the Lar system, where environmental and physiological factors, such as gender and age, influence immune function, particularly IgM production, making this study crucial for understanding their humoral immunity. This study aimed to determine the immunoglobulin M profile of Sumbawa horses raised in the Lar system (a traditional extensive grazing method) of Sumbawa Island. Materials and methods: Serum samples were collected from 70 Sumbawa horses, categorized by gender (36 males and 34 females) and age group (34 young: below 12 months; 36 adults: above 12 months). The immunoglobulin M levels in the blood serum were measured using the Enzyme-Linked Immunosorbent Assay. Results:  The results indicated detectable immunoglobulin M concentrations in all 70 serum samples, ranging from 1.792 μg/mL to 51.341 μg/mL. The average serum immunoglobulin M levels were higher in female horses (23.8822 ± 12.15941 μg/mL) compared to males (20.1091 ± 9.51380 μg/mL). Similarly, young horses (22.9249 ± 11.90000 μg/mL) exhibited higher immunoglobulin M levels than adults (21.0132 ± 10.08383 μg/mL). Despite these differences, statistical analysis showed no significant differences among the groups.  Conclusion: The average immunoglobulin M levels observed in this study provide baseline data for the immunoglobulin M profile of Sumbawa horses raised under the traditional grazing system on Sumbawa Island, Indonesia. https://fahn.rovedar.com/index.php/FAHN/article/view/65 Sumbawa horse Sumbawa Island Immunoglobulin M Immune system