BCRC 3 - Gene Discovery for Post Partum Reconception and Age of Puberty in the Australian Beef population

Summary

The aim of this project was to develop DNA-based tools to help the northern Australian beef industry achieve reduced age at puberty and improve postpartum re-conception in first lactation cows. Genome-wide association studies were conducted on the Beef CRC Northern Breeding Project resource population. A total of 1,709 female cattle (843 Brahman and 866 Tropical Composites), with phenotypic records for lifetime reproductive performance and other production traits, were genotyped with the Illumina Bovine SNP50 chip. The study was able to identify significant associations between many single nucleotide polymorphisms (SNP) and the two traits in the two populations studied. These SNP associations were used as the basis for genomic prediction equations and incorporated into genomically-enhanced Breedplan Estimated Breeding Values (gEBV). To test whether smaller panels of markers could be used to aid genetic selection for reproductive traits, a panel of 10 SNP per breed and per trait was tested for its effectiveness. Genome regions with significant SNP associations were further investigated for possible causative genes. Significant SNP and possible causative genes could be used to enhance the accuracy of genomic selection. The results have built a platform for future delivery of DNA-based predictions of genetic merit for female reproduction in tropically adapted breeds.