Integrative transcriptomic, flow cytometric and DNA integrity analysis of frozen semen in relation to fertility in Kankrej (Bos indicus) bulls

This study examined fertility differences in Kankrej bulls, an important indigenous cattle breed. Bulls were grouped as high-fertile or low-fertile, and their sperm were analyzed using both RNA sequencing and flow cytometry. The analysis identified 36 genes with different activity levels between the two groups, with many linked to metabolism and other vital cellular functions. Flow cytometry showed that high-fertile bulls had more viable sperm with intact acrosomes and stronger mitochondrial activity, while low-fertile bulls showed higher rates of sperm damage. These results suggest that combining sperm gene expression profiling with flow cytometric evaluation provides a reliable way to assess and predict fertility in bulls, supporting better breeding strategies for indigenous cattle.