A recent study led by Hubert Pausch, Professor of Animal Genomics at ETH Zurich, published in Nature Communications, delved into the genes influencing male fertility in bulls, shedding light on potential implications for human and livestock fertility.

The research team from the Institute of Agricultural Sciences examined reproductive organs' tissues from 118 young bulls, including testicles, epididymis, and vas deferens, without the animals being killed for the purpose of the study.

By analyzing the transcriptomes of the bulls' genes within different tissues, researchers identified various gene variants associated with fertility in bulls, with implications also extending to human male fertility. Xena Mapel, the study's first author, emphasized the evolutionary conservation of genes regulating male fertility across mammals.

The study highlighted how the risk of subfertility in bulls can now be identified through new marker genes not detectable through conventional ejaculate screening methods. Furthermore, the research emphasized the advantage of using bulls as an animal model due to the understanding of breeding bull genetics and routine semen analysis in breeding practices.

The findings are expected to assist livestock breeders in minimizing financial losses from unsuccessful artificial inseminations. With each insemination costing 80 Swiss francs, the study brings both economic and practical benefits to the industry, where millions of cows are artificially inseminated annually in Switzerland alone.

The results also allude to potential improvements in diagnosing male fertility disorders in humans, given the shared genetic underpinnings found in bulls. This study marks a significant step towards understanding male fertility mechanisms in both livestock and humans, with practical implications for farmers and healthcare providers alike.

For more details, Xena Marie Mapel et al.'s study titled "Molecular quantitative trait loci in reproductive tissues impact male fertility in cattle," can be accessed in Nature Communications (2024), DOI: 10.1038/s41467-024-44935-7.