Feed Efficiency Genetic Projects

1
Feed EfficiencyGenetic 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

• Must measure individual intake

Dave Kirschten, Cornell University
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
Weight Measurements
EPDs for Mature Size and Milk
Genetic evaluation system
Pedigree
Use mature size and milk EPDs ? Cow Maintenance
Requirement EPDs - Evans et. al.
8
Another Option
Use data on related traits (indicators) to
predict the EPDs for the ERT.
9
Evaluations
Weight Traits Carcass Traits
Genetic evaluation system
EPDs for Feed Efficiency
Pedigree
Herring and Bertrand
10
Another Option
Use data on related traits (indicators) to
predict the phenotype for the ERT.
11
Evaluations
e.g. Cornell Value Discovery System
Data
Genetic evaluation system
EPDs
Pedigree
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
Exactly the carcass / ultrasound model!!
Both
Seedstock progeny
15
Project Heritability
Dannys 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.
Heritability PDMR .32 ADG .36
16
Project Heritability
Collaborative project with breed associations to
collect data on individual bulls on performance
tests.
Data from Circle A ranch in Missouri.
Objective Estimate the heritability of PDMR and
the genetic correlations between PDMR and other
traits.
17
Project Texas AM, King Ranch, NBCEC, Texas CF,
and NCBA checkoff dollars
CG of Calves produced at the King Ranch