Post on 25-Dec-2015
Experiences with the Experiences with the Implementation of Implementation of
Stayability EPDStayability EPD
Wade ShaferAmerican Simmental AssociationBozeman, MT
•Fertility•Survivability•Structural Soundness•Disposition•Productivity
Traits Impacting StayabilityTraits Impacting Stayability
IT ’s IT ’s In In ThereThere!!
Does Increasing the Does Increasing the Stayability of Your Cowherd Stayability of Your Cowherd Improve Your Bottom Line?Improve Your Bottom Line?
Environment Genetics
Maybe Yes
What is the Most What is the Most Effective Way to Effective Way to
Genetically Improve Genetically Improve Stayability?Stayability?Crossbreed!!!!
The Biology of The Biology of CrossbreedingCrossbreeding
Breed Breed AA
Stayability
Carcass
Additive gene action
Non-additive gene actionEPDs
A x BA x B
Breed Breed BB
Heterosis
Does a Stayability EPD Does a Stayability EPD Have Value?Have Value?
Yes!Improving the additive component of Stayability is like adding icing to the cake
The Biology of The Biology of CrossbreedingCrossbreeding
Breed Breed AA
Stayability
Additive gene action
Non-additive gene actionEPDs
A x BA x B
Breed Breed BB
Heterosis
The Biology of The Biology of CrossbreedingCrossbreeding
Breed Breed AA
Stayability
Additive gene action
Non-additive gene actionEPDs
A x BA x B
Breed Breed BB
Heterosis
The Biology of The Biology of CrossbreedingCrossbreeding
Breed Breed AA
Stayability
Additive gene action
Non-additive gene actionEPDs
A x BA x B
Breed Breed BB
Heterosis
The Biology of The Biology of CrossbreedingCrossbreeding
Breed Breed AA
Stayability
Additive gene action
Non-additive gene actionEPDs
A x BA x B
Breed Breed BB
Heterosis
ASA’s All-Purpose Index
• Bred to all-aged females• Retain replacements• Culls sold grade and Yield• Straightbred AN cowherd• Prices and costs based on 5-yr
CattleFax average
Does a Stayability EPD Does a Stayability EPD Have Value?Have Value?
Using a sire two standard deviations better for Stayability (bottom to top third) improves your profitability by $45/cow exposed
LOTS!
• Is it an economically relevant trait?
Stayability EPD Stayability EPD ChecklistChecklist
Yes… VERY!
• Can it be selected for?
Yes… but…
Challenges with Challenges with StayabilityStayability
• Stayability is a lowly heritable trait expressed late in life
• Breed association data tends to be less than ideal for calculating Stay EPD
“I don’t need an EPD to make progress in stayability. I just send all my ‘problem’ cows to town.”
Challenges with Stay:Challenges with Stay: low low heritabilityheritability trait expressed trait expressed late in lifelate in life
Challenges with Stay:Challenges with Stay: low low heritabilityheritability trait expressed trait expressed late in lifelate in life
Without EPDs little if any progress is made in low-heritability traits Phenotypes
Stayability
Challenges with Stay:Challenges with Stay: low low heritabilityheritability trait expressed trait expressed late in lifelate in life
Without EPDs little if any progress is made in low-heritability traits low/med-acc EPD
Stayability
Challenges with Stay:Challenges with Stay: low low heritabilityheritability trait expressed trait expressed late in lifelate in life
Without EPDs little if any progress is made in low-heritability traits high-acc EPD
Stayability
“What good is an EPD that doesn’t have much accuracy until a sire is dead and gone?”
Challenges with Stay:Challenges with Stay: low low heritability trait heritability trait expressed expressed late in lifelate in life
Good Question!
Current options:
Challenges with Stay:Challenges with Stay: low low heritability trait heritability trait expressed expressed late in lifelate in life
Future developments:
Use the sure-bet “old man”Use several promising young bucks
Use all available information: Move away from pass/fail grading Add indicator traits to model
Gene markers
Challenges with Challenges with StayabilityStayability
• Breed association data tends to be less than ideal for calculating Stay EPD
Sketchy—potentially biased
May not be reflective of commercial culling
Traits Impacting StayabilityTraits Impacting Stayability
It’s It’s ALL in ALL in there!there!
FertilitySurvivabilityStructural SoundnessDispositionProductivityColor PatternPolled/hornedPopularity???
Challenges with Stay:Challenges with Stay: breed assoc. data tends to be breed assoc. data tends to be less than idealless than idealCurrent options:
Future developments:
Use common senseUse a few sure-bet “old men”Use several promising young bucks
Inventory-based reporting systemsUser-defined stayability