Emerging Proteomic Approaches in Sperm Sorting: Shaping the Future of Reproductive Biotechnology

Sperm sexing is a prominent Assisted Reproductive Technology (ART) that enhances reproductive efficiency, boosts production and improves the economic viability of dairy farms. To meet the growing demand for milk and dairy products, improvements in genetic selection and breeding strategies are imperative. Towards this goal, the use of sex-sorted semen enables the preferential production of female calves, thereby directly contributing to faster genetic gain, increased milk yield, and an optimised herd structure. At present, the commercially available and widely adopted sperm sexing technique is flow cytometry, offering up to 90% sorting accuracy based on the difference in DNA content. However, its widespread application is limited due to high operational costs, technical complexity, and potential adverse effects on sperm viability and fertility. Recent advancements in proteomics and immunological methods have opened new avenues for developing cost-effective, non-invasive sperm-sorting technologies. Such approaches are designed to enhance sorting efficiency, maintain sperm integrity, and offer methods that can be effectively implemented on a larger scale to meet breeders' requirements. This review discusses the current status, technological limitations, regulatory frameworks, and future prospects of proteomic and immune-based strategies in bovine sperm sexing, with a focus on their potential to transform flexible bovine productivity at large.