GENOME-WIDE ASSOCIATION STUDY FOR MILK AND PROTEIN YIELDS IN PORTUGUESE HOLSTEIN CATTLE

Abstract Text: Genome-wide association studies were performed to identify QTL associated with the EBV of milk and milk-protein yields in Portuguese Holstein cattle. Genotypes of 526 sires were obtained using the Illumina-BovineSNP50-BeadChip. After quality control procedures, the number of validated SNPs was 37,031 from 29 autosomes. Nine markers were detected to be associated with milk yield, five of which were significant at P < 10^‑4 and located on BTA1, BTA10, BTA12 and BTA13. The remaining four were significant at P < 5 x 10^-5 and located on BTA13, BTA14, BTA24 and BTA26.  Five markers were found to be associated with milk-protein yield. Four of these were significant at P < 10^‑4 and located on BTA6, BTA7, BTA21 and BTA25, while one marker located on BTA18 was significant at P < 5 x 10^-5. The Hapmap24715-BTC-001973 SNP in BTA14 may be associated with QTLs affecting milk traits and deserves further studies.

Keywords:

Dairy cattle

Milk yield

Protein yield

Genome-wide association