Bio-Genesys Diagnostics is collaborating with a team at the Universidad de León, Spain, to carry out a genomic study of three dairy sheep breeds. The research study is financed by the Spanish Ministry of Agriculture, Food and the Environment (MAGRAMA) and focuses on using genomic selection to improve the genetics for milk production traits such as milk quality, udder health and fertility, for three breeds: Assaf, Churra and Lacaune.
The proposed experimental design will establish three reference populations, with 1000 animals for each breed. The research team is led by Professor Juan José Arranz Santos, from the Department of Animal Production at the Universidad de León and involves researchers from four different groups, with expertise ranging from genetic improvement in dairy sheep to developing genomic methodologies. The team is designing a 50,000 SNP chip to use for testing the reference populations. Bio-Genesys will carry out the 3000 genotyping tests with the 50K SNP chip, on the Affymetrix Axiom 384HT Platform.
The resulting genomic information will be combined with productivity data provided by the breed associations, to estimate statistical associations between various SNPs and particular productivity traits. This study includes milk traits (milk yield, protein percentage, milk fat percentage), health traits (SCC) and reproductive traits (fertility, prolificacy).
This methodology represents a new approach for the dairy sheep breeding sector, so different strategies will be used to estimate the statistical associations between genomic markers and productivity traits and the best strategies will be determined using large computer simulations.
"We expect that the main outcomes of this project will be an improvement in the reliability of genetic value estimates for male animals chosen for reproduction, a shorter generation interval and the possibility of using the results to choose replacement females," said Professor Arranz. "These are key factors for improving the profitability of dairy sheep production".
The same 50K SNP chip will eventually be used for testing up to 8 different breeds of dairy sheep. In the case of small dairy sheep populations where a reference population cannot be established due to the small numbers involved, it is theoretically possible to create a mixed breed reference population to use in an initial evaluation of potential sires. The feasibility and accuracy of such an approach will be studied as part of this genomic project and may make this process more accessible to dairy sheep producers with smaller flocks.