1. Feed Efficiency Genetic Projects

2. Terms Gain/Feed = Feed Efficiency FE Feed/Gain = Feed Conversion FC: -FE Residual Feed Intake RFI Net Feed Intake NFI:-RFI

3. Effects of Selection for FE or FC  Size at given age  Gain  Muscle  Fat: External and Intramuscular  Must measure individual intake Dave Kirschten, Cornell University

4. Residual Feed Intake Observed DMI – Expected DMI  Expected DMI given f(weight.75,ADG)   = Favorable Dave Kirschten, Cornell University

5. Response to Selection for RFI  Intake  Gain, Test Weight  Weaning Weight, Yearling Weight of Progeny  Lean Percent  Marbling  Feed Efficiency Dave Kirschten, Cornell University  Must measure individual intake

6. Indicator Traits Useful when the ERT, is: 1 - difficult to measure, 2 - expensive to measure, or 3 - measured late in life. Option: not measure the trait but provide evaluations based on associated information

7. Evaluations Genetic evaluation system Weight Measurements Pedigree EPD’s for Mature Size and Milk Use mature size and milk EPD’s  Cow Maintenance Requirement EPD’s - Evans et. al.

8. Another Option Use data on related traits (indicators) to predict the EPD’s for the ERT.

9. Evaluations Genetic evaluation system Weight Traits Carcass Traits Pedigree EPD’s for Feed Efficiency Herring and Bertrand

10. Another Option Use data on related traits (indicators) to predict the phenotype for the ERT.

11. Evaluations Genetic evaluation system Pedigree EPD’s e.g. Cornell Value Discovery System Data Predicted Phenotypes Data Biological Model

12. Predicted Phenotypes The CVDS can be used for feedlot animals (carcass and feedlot data) as well as breeding animals (ultrasound and ranch data).

13. Predicted Phenotypes Sire Slaughter progeny Seedstock progeny Opportunity for “large” volumes of data!

14. Multiple Trait Approach Slaughter progeny Seedstock progeny Both Exactly the carcass / ultrasound model!!

15. Project: Heritability Heritability: PDMR =.32 ADG =.36 Danny’s group has been working with the Jorgenson herd on predicting the Dry Matter Requirements (PDMR) of bulls on test. The PDMR has been obtained on 747 performance tested bulls during those three years and these bulls were themselves progeny of 84 sires.

16. Project: Heritability Objective: Estimate the heritability of PDMR and the genetic correlations between PDMR and other traits. Collaborative project with breed associations to collect data on individual bulls on performance tests. Data from Circle A ranch in Missouri.

17. Project: Texas A&M, King Ranch, NBCEC, Texas CF, and NCBA checkoff dollars CG of Calves produced at the King Ranch Group to Texas A&M for individual feeding, intense data collection and evaluation. Group kept at King Ranch and pen fed. Data collected to meet the requirements of the CVDS