Agriculture and Agri-Food Canada Agriculture et Agroalimentaire Canada Multiple Trait Selection for...
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![Page 1: Agriculture and Agri-Food Canada Agriculture et Agroalimentaire Canada Multiple Trait Selection for Maternal Productivity D. H. Crews, Jr., P. B. Mwansa.](https://reader036.fdocuments.net/reader036/viewer/2022082822/5697bfda1a28abf838cafd52/html5/thumbnails/1.jpg)
Agriculture andAgri-Food Canada
Agriculture etAgroalimentaire Canada
Multiple Trait Selection for Maternal Productivity
Multiple Trait Selection for Maternal Productivity
D. H. Crews, Jr., P. B. Mwansa and R. A. Kemp
Agriculture and Agri-Food Canada Research Centre, Lethbridge, AB
![Page 2: Agriculture and Agri-Food Canada Agriculture et Agroalimentaire Canada Multiple Trait Selection for Maternal Productivity D. H. Crews, Jr., P. B. Mwansa.](https://reader036.fdocuments.net/reader036/viewer/2022082822/5697bfda1a28abf838cafd52/html5/thumbnails/2.jpg)
Agriculture andAgri-Food Canada
Agriculture etAgroalimentaire Canada
What is maternal productivity?What is maternal productivity?
• Reproductive rate– Age at puberty– Heifer pregnancy rate, calving ease and 3 yr old rebreed rate– Persistence into profitable parities
• Calf growth– Direct genetics for growth– Maternal genetics milk production
• Cow maintenance requirements– Weight– Intake Can’t measure this
Low heritability, Difficult evaluation
Everyone already does this
![Page 3: Agriculture and Agri-Food Canada Agriculture et Agroalimentaire Canada Multiple Trait Selection for Maternal Productivity D. H. Crews, Jr., P. B. Mwansa.](https://reader036.fdocuments.net/reader036/viewer/2022082822/5697bfda1a28abf838cafd52/html5/thumbnails/3.jpg)
Agriculture andAgri-Food Canada
Agriculture etAgroalimentaire Canada
Data and InformationData and Information
• One obstacle to new index development is capturing information on “new” traits
• We are often limited by what data is routinely and comfortably recorded in national databases
You want to
measure what?!?
![Page 4: Agriculture and Agri-Food Canada Agriculture et Agroalimentaire Canada Multiple Trait Selection for Maternal Productivity D. H. Crews, Jr., P. B. Mwansa.](https://reader036.fdocuments.net/reader036/viewer/2022082822/5697bfda1a28abf838cafd52/html5/thumbnails/4.jpg)
Agriculture andAgri-Food Canada
Agriculture etAgroalimentaire Canada
Multiple Trait SelectionMultiple Trait Selection
Measure This
• Growth• Cow weight• Calves ÷ Reproductive years
Evaluate This
• Maternal Productivity
What is your MPI?
Moo.
![Page 5: Agriculture and Agri-Food Canada Agriculture et Agroalimentaire Canada Multiple Trait Selection for Maternal Productivity D. H. Crews, Jr., P. B. Mwansa.](https://reader036.fdocuments.net/reader036/viewer/2022082822/5697bfda1a28abf838cafd52/html5/thumbnails/5.jpg)
Agriculture andAgri-Food Canada
Agriculture etAgroalimentaire Canada
Trait DefinitionsTrait Definitions
• Direct weaning weight• Maternal weaning weight• Cow weight at calf weaning
– Indicator for maintenance costs
• Stayability– Pr(3 | 1) = probability that a female will have at
least three calves given she became a dam
![Page 6: Agriculture and Agri-Food Canada Agriculture et Agroalimentaire Canada Multiple Trait Selection for Maternal Productivity D. H. Crews, Jr., P. B. Mwansa.](https://reader036.fdocuments.net/reader036/viewer/2022082822/5697bfda1a28abf838cafd52/html5/thumbnails/6.jpg)
Agriculture andAgri-Food Canada
Agriculture etAgroalimentaire Canada
Multiple Trait Selection Index: ObjectiveMultiple Trait Selection Index: Objective
• The selection objective was to increase genetic potential to consistently wean heavy calves while maintaining input costs which yielded an aggregate genetic value function:
MPI = v1 WWT + v2 MLK + v3 CWT + v4 STY
with resulting economic weights:v1 = 1.17
v2 = 0.98
v3 = -0.14
v4 = 2.39
![Page 7: Agriculture and Agri-Food Canada Agriculture et Agroalimentaire Canada Multiple Trait Selection for Maternal Productivity D. H. Crews, Jr., P. B. Mwansa.](https://reader036.fdocuments.net/reader036/viewer/2022082822/5697bfda1a28abf838cafd52/html5/thumbnails/7.jpg)
Agriculture andAgri-Food Canada
Agriculture etAgroalimentaire Canada
MPI NCE Genetic ParametersMPI NCE Genetic Parameters
0.74
-0.34
0.67
-0.45
-0.24
0.85
-0.44
-0.17
0.01 -0.48
0.48
0.11
0.19
0.18
0.24
0.50
0.07
BWTd
BWTm
WWTd
WWTm
WWTpe
CWTd
STYd
BWTd BWTm WWTd WWTm WWTpe CWTd STYd
![Page 8: Agriculture and Agri-Food Canada Agriculture et Agroalimentaire Canada Multiple Trait Selection for Maternal Productivity D. H. Crews, Jr., P. B. Mwansa.](https://reader036.fdocuments.net/reader036/viewer/2022082822/5697bfda1a28abf838cafd52/html5/thumbnails/8.jpg)
Agriculture andAgri-Food Canada
Agriculture etAgroalimentaire Canada
Relative EmphasisRelative Emphasis
• The relative contribution of component traits to variation in the index– Weaning weight = 30%– Milk = 25%– Cow weight = 13%– Stayability = 27%
WWT
MLK
CWT
STY
![Page 9: Agriculture and Agri-Food Canada Agriculture et Agroalimentaire Canada Multiple Trait Selection for Maternal Productivity D. H. Crews, Jr., P. B. Mwansa.](https://reader036.fdocuments.net/reader036/viewer/2022082822/5697bfda1a28abf838cafd52/html5/thumbnails/9.jpg)
Agriculture andAgri-Food Canada
Agriculture etAgroalimentaire Canada
Making the MPI User FriendlyMaking the MPI User Friendly
• The MPI can be interpreted as any other EPD– It is a combination of EPD with relative economic
values– The units are $ differences
• Information packaging is an important part of making indexes useful selection tools rather than only marketing tools
• The MPI can be expressed with any mean and variance– e.g. mean = 100, SD = 25
![Page 10: Agriculture and Agri-Food Canada Agriculture et Agroalimentaire Canada Multiple Trait Selection for Maternal Productivity D. H. Crews, Jr., P. B. Mwansa.](https://reader036.fdocuments.net/reader036/viewer/2022082822/5697bfda1a28abf838cafd52/html5/thumbnails/10.jpg)
Agriculture andAgri-Food Canada
Agriculture etAgroalimentaire Canada
MPI ValidationMPI Validation
• What differences in animals are we evaluating?– Is the MPI the same as selection for component traits?
• Separation of MPI evaluation into high and low groups– High = > 2 SD greater than the mean MPI (n = 17,328)– Low = > 2 SD less than the mean MPI (n = 11,496)– Comparison of standardized component EPD between
groups
• What component traits are most related to the MPI?
![Page 11: Agriculture and Agri-Food Canada Agriculture et Agroalimentaire Canada Multiple Trait Selection for Maternal Productivity D. H. Crews, Jr., P. B. Mwansa.](https://reader036.fdocuments.net/reader036/viewer/2022082822/5697bfda1a28abf838cafd52/html5/thumbnails/11.jpg)
Agriculture andAgri-Food Canada
Agriculture etAgroalimentaire Canada
Component Traits in High and Low MPI GroupsComponent Traits in High and Low MPI Groups
STY
CWT
MLK
WWT
-10 -5 0 5 10
![Page 12: Agriculture and Agri-Food Canada Agriculture et Agroalimentaire Canada Multiple Trait Selection for Maternal Productivity D. H. Crews, Jr., P. B. Mwansa.](https://reader036.fdocuments.net/reader036/viewer/2022082822/5697bfda1a28abf838cafd52/html5/thumbnails/12.jpg)
Agriculture andAgri-Food Canada
Agriculture etAgroalimentaire Canada
To Summarize…To Summarize…
• The MPI was developed with the breeding objective to increase genetic potential to consistently wean heavier calves over a sustained productive life while maintaining input costs
• Annual or generational genetic trend is expected to be positive for all component traits, however, cow weight increases would be minimal
• As a multiple trait index, component trait values vary:– Animals with different component EPD have similar MPI
![Page 13: Agriculture and Agri-Food Canada Agriculture et Agroalimentaire Canada Multiple Trait Selection for Maternal Productivity D. H. Crews, Jr., P. B. Mwansa.](https://reader036.fdocuments.net/reader036/viewer/2022082822/5697bfda1a28abf838cafd52/html5/thumbnails/13.jpg)
Agriculture andAgri-Food Canada
Agriculture etAgroalimentaire Canada
… Summary… Summary
• The MPI places more relative emphasis on maternal characteristics and stayability than on growth
• Accuracy and intensity are greatly reduced when data (information) is lacking on grandprogeny
• MPI selection is not equivalent to selection for any of the component traits alone
• Validation with maternal indexes is a challenge– MPI validation is still largely to be conducted
• The MPI needs to be expanded to include more components, which will come with data