Analysis of genetic and performance data in dairy herds

In recent years, genetic progress has accelerated, largely because of advances in the genomic testing of bulls (Guinan et al, 2023). This has shortened the generation interval and increased the rate of genetic improvement (García-Ruiz et al, 2016). Bulls are now marketed based on genomic breeding values before any phenotypic data are available from their progeny. Another significant development is the improvement in the quality and availability of dairy-sexed semen, allowing farmers to be more selective about which animal replacements are bred from. Conception rates to sexed semen have improved and are now between 83% and 100% as effective as conventional semen (Crites et al, 2018; Oikawa et al, 2019; Irish Cattle Breeding Federation, 2023).

Data quality is also improving. In the UK in 2023, 20% of heifer registrations were genomically tested, representing a significant increase in recent years (Agriculture and Horticulture Development Board (AHDB), 2024). This compares with 20–25% of heifers registered in the US(CoBANK, 2024).