Project Number: 1265-31000-096-09
Project Type: Specific Cooperative Agreement

Start Date: Jun 22, 2007
End Date: May 31, 2009

Objective:
Develop statistical, quantitative genetic, genomic, biometric, and computing technologies for use in combining genotypic information from DNA from bulls provided by artificial insemination organizations with phenotypic data on yield and fitness traits.

Approach:
Research is directed at developing genomic tools to estimate effects of chromosome segments or individual genes. Previous joint research have used widely spaced markers and found loci with large effects, but confirmed that genetic variation for most traits is quantitative, with many loci distributed across the genome individually exerting small effects. Planned research will estimate the trace inheritance of the many smaller genetic effects by using available single nucleotide polymorphisms (SNPs). Research is directed toward predicting transmitting abilities (PTA) more accurately by simultaneously predicting effects of many genetic loci using dense marker genotypes. Phenotypic data used for this will be from the national genetic evaluations for traits currently evaluated. Data will be expressed as daughter yield deviations or as de-regressed PTAs to avoid reanalysis of all raw records. Use of dense markers to estimate chromosome segment effects avoids most of the recombination between markers and causative genes that reduced the accuracy of previous within-family analyses. Predictions for young bulls will be more reliable when DNA samples for these are obtained in a later phase of the research.