The Expression of Plasma Protein in Bali-polled Bulls Using 1D-SDS-PAGE

The fertility rate of bulls in a breeding program is not only described by the quantity and quality of semen. Factors, such as the interstice factor of the sperm and the plasma component of semen, affect the fertility rate of bulls. The fertility rate can also be determined by identifying the protein content of semen plasma. Therefore, the current study aimed to identify the relationship between seminal plasma protein molecular weight and semen quality of Bali- polled bulls. The study was conducted at the Laboratory of Semen Processing, Faculty of Animal Science, Hasanuddin University, Makassar, Indonesia, the Research Center for Applied Zoology, National Research and Innovation Agency, Cibinong, Indonesia and the Laboratory of Animal Biotechnology Center, IPB University, Bogor, Indonesia from November 2021 to January 2022. The samples came from 5 Bali-polled and 5 Bali-horned bulls. Semen collection was conducted twice a week using an artificial vagina. The concentration of seminal plasma protein was determined by the Bradford method of 1D-SDS-PAGE. The study results showed that fresh semen of Bali-polled and Bali-horned bulls was considered a normal category. Seminal plasma proteins of Bali-polled and Bali-horned bulls were classified using 8 bands to categorize molecular weight; 150 kD (IGF-1), 110 kD (A-kinase anchoring protein 3), 93 kD (A-kinase anchoring protein 4), 54-87 kD (Arylsulfatase-a), 44-62 kD (N-Acetyl-ß- Guicosaminidase), 44kD (Phosphoglycerate kinase), 15-30 kD (BSP A1/A2, BSP-A3 and BSP-30 [BSP1, BSP3, and BSP5]) and 12-14 kD (Acidic seminal fluid proteins). The findings indicated that both Bali-polled and Bali- horned bulls could have a high reproductive rate. In conclusion, protein analysis based on molecular weight using 1D-SDS-PAGE can be used as a biomarker for semen quality in Bali-polled bulls. Therefore, evaluating the semen quality with a molecular basis as an additional indicator of superior bull in the selection process is an alternative method.