Predicting energy balance for dairy cows using high-density single nucleotide polymorphism information.

Area of Science:

• Animal Genetics
• Quantitative Genetics
• Livestock Breeding

Background:

• Energy balance (EB) is crucial, linking production and non-production traits in livestock.
• Understanding the genetic architecture of EB is essential for improving animal health and productivity.
• Genomic selection offers a potential tool to incorporate complex traits like EB into breeding programs.

Purpose of the Study:

• To investigate the genetic basis of energy balance (EB) in Dutch Holstein-Friesian heifers.
• To evaluate the potential of genomic selection for incorporating EB into livestock selection programs.
• To compare the accuracy of genomic predictions with traditional estimated breeding values.

Main Methods:

• Genotyping of 527 Dutch Holstein-Friesian heifers with EB phenotypes.
• Prediction of direct genomic values using genotypic information.
• Application of a polygenic model for estimated breeding values using pedigree data.
• 10-fold cross-validation to assess prediction accuracies against phenotypes.

Main Results:

• Genomic model breeding values showed double the reliability of polygenic model breeding values.
• Accuracies for genomic (0.29) and estimated breeding values (0.21) were relatively low due to limited phenotypes (max possible 0.57).
• Genomic selection demonstrated potential for selecting minimally recorded traits, such as EB.

Conclusions:

• Genomic selection is a viable tool for selecting energy balance (EB) in livestock.
• The study confirmed the genetic background of EB, supporting its heritability.
• Improving EB measurement and recording is necessary to increase the accuracy of genomic breeding values and selection efficacy.