Advances in Biology & Earth Sciences

This study aimed to characterize the seminal plasma proteome of three indigenous Indonesian bull breeds - Bali, Pasundan and Donggala - to identify reproductive-associated proteins and provide molecular insights into breed-specific fertility traits in tropical livestock systems. Seminal plasma was collected from 15 bulls (five from each breed) and analyzed using 1D SDS-PAGE followed by LC-MS/MS, with functional annotation conducted via Gene Ontology and STRING databases. A total of 364 unique proteins were identified, with Bali bulls exhibiting the highest number of breed-specific proteins (195), followed by Donggala (172) and Pasundan (130). No protein was shared across all three breeds, indicating distinct proteomic profiles. Functional enrichment analyses revealed that Bali bulls had proteins related to motility and metabolism, Pasundan bulls to structural and acrosomal functions and Donggala bulls to transport and cytoskeletal stability. Key reproductive-associated proteins such as BSP1, TEX101, IZUMO1 and HSPA1L were identified and interaction networks highlighted specialized molecular strategies related to sperm function. These findings demonstrate significant inter-breed variation in seminal plasma composition, reflecting adaptations to tropical environments and provide a molecular foundation for fertility biomarker discovery and precision breeding in underrepresented bovine populations.