Validation of DNA Testing for Carcass Traits

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Validation of DNA Testing for Carcass Traits
John Pollak Cornell University
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Objectives of DNA Project Team

• Develop protocol for validation (or not) of
  results with independent (field) data

DNA team Richard Quaas (CU), Rohan Fernando
(ISU) and Mark Thallman (MARC)
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DNA Tests for Carcass Merit Traits

• GeneStar Marbling
• Mu-Calpain
• Calpistatin
• Leptin
• Marked QTL from NCBA Carcass Merit Project (genes
  unknown)

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NBCEC Data

• Marbling scores on 277 cattle w/ genotypes
• Progeny of 19 sires /- /
• genotyped Simmental bulls
• ASA progeny test data (mostly CMP)
• 11 contemporary groups
• Marbling scores on 272 contemporaries
• 49 total sires of progeny w/ MS

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Slide courtesy of Jay Hetzel
A simple result
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NBCEC vs. Genetic SolutionsMarbling Score Results
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(No Transcript)
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NBCEC vs Genetic Solutions Choice Results
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mu-Calpain

• mu-Calpain or Calpain 1
• Post-mortem degradation of myofibrillar proteins
• Tenderness
• W-B Shear force
• Calpastatin (GeneStar tenderness)
• regulates Calpain

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NBCEC mu-Calpain Analysis

• 2 SNP markers in calpain gene
• Analyzed W-B shear force
• Each marker separately
• Together
• Additive
• Interaction

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Mu-Calpain 2 Additive Genotypes
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Mu-Calpain 2 Additive Genotypes
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Others?

• Leptin
• Meriel
• In our population of cattle used for validation
  we did not find an effect of the polymorphism in
  the Leptin gene for marbling.

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NCBA Carcass Merit Project

• Objectives
• Investigate genetic components for tenderness and
  sensory panel information including potential for
  developing EPDs and QTL for DNA testing.

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DNA Component of CMP

• Validation of QTL discovery
• Texas AM Angelton Project
• (Angus and Brahman cross cattle)
• 11 QTL candidates selected
• 12 phenotypes analyzed