The breeding program for Norwegian Red has through decades included traits of low heritability resulting in good fertility, something which the breed is now internationally recognised for.
Our research was performed on Norwegian Red bulls, providing Geno with potential points for improvements.
The sperm stress test and cryopreservation combined with early sperm morphology could aid identification of bulls with good freezing ability and would be a practical test for breeding companies to carry out in the laboratory.
To our knowledge, this is the first time scrotal circumference measurements of bulls were automated with the use of convolutional neural networks and 3D images. This innovative approach, combined with a user–friendly application, allows a fast integration into breeding soundness evaluation of Norwegian Red bulls at the performance test and bovine semen collection centres.
Other breeds, now facing challenges concerning fertility, might have even bigger benefits from implementing methods suggested in our work.
Thus, international cattle breeding could benefit from corresponding research performed on other breeds.
Main findings:
- Our work demonstrated that young Norwegian Red bulls reach maturity in sperm quality at different ages, which will require early andrology testing and individualised selection at the performance test station.
- To improve the selection criteria for AI station at the youngest possible age, we propose to use the novel interpretation of the sperm stress test and cryopreservation combined with early sperm morphology analysis to elucidate the sperm quality status of young bulls.
- We conclude that using our novel automated scrotal circumference measurement method at the performance test station could be of interest to the breeding companies.
Here you can find more information about Joanna Bremer's dissertation on September 19, 2023.