Genetic Testing Large Animals Flashcards
(41 cards)
Why do we do genetic testing
- health
- conformation/ apperance
- inheritance
- breeding value
- ancestry
- production
- inbreeding
Application of genetic testing
how we interpret genetic test results and what we do with them
- medical tx
- culling
- marketing
- rearing/ maintenance
- breeding
Who does gene testing
- breed associations
- internationa/ national associations
- genotyping companies
- AI companies
- Academic institutions
Uses of genetic testing
- depends on acceptance by general public and for industry adoption and use of it
- can be used by individual or by a group
- can be used to educate the public vs to educate a user
genetic test pricing
high density= higher number of markers= higher price= higher accuracy
- realistically the accuracy is fairly close and for the 5% difference in accuracy most consumers will go with lower density and lower price
DNA sample options
- hair
- blood
- tissue
- nasal swab
- semen
genetic merit
what is the genetic value of the animal; objective score of that animals value
- estimate for this evolved from looking at phenotype and pedigree
- now look at phenotype genotype and pedigree this allows you to estimate values of traits not exhibited (ex milk production in bulls)
parent average
genetic average of each parent’s genetic value; assumes offspring inherit exactly 1/2 of parents genetic merit for all traits and that parents are 100% correctly IDed
estimation of genetic merit
- genotypic value
- breeding value
- progeny difference= transmitting ability
- producing ability
genotypic value
value of an individuals genes on their own performatnce
breeding value
value of an individuals genes on their progeny’s performance
progeny difference= transmitting ability
expectation of what progeny inherits from their parents
producing ability
performance potential of an individual for a repeated trait (Ie milk production in a dairy cow)
progeny testing vs genomic prediction
investment progeny testing= time and cost or raising animal and progeny until performance evaluated
investment genomic prediction= genomic research, industry infrastructure, producer buy in
genomics- has better accuracy of genetic merit and trait selection, lets you evaluate merit of young stock, validate parentage, check for cacciers for genetic conditions
genomic prediction
- need a reference population so take all of these cows who’s phenotypes for things like milk production have been recorded and genotype them
- get prediction equations associations between SNP and phenotypes (what marker indicates what phenotype) and look at how that gives genetic merit
- once you have reference pop must still keep sequencing because populations change
Rate of genetic change equation
Expected genetic progress per year= { (square root of genetic variance) (selection differential ie intensity) (square root of accuracy)}/ generational interval
genetic variance
variation in population due to genetics; includes heritability (h^2) of trait
* we can not change this*
selection differential
intensity of selection; how selective we are when making mating decisions
accuracy
how certain we are about our estimate of an animals genetic merit
generation interval
time between generatiosn
what’s included in genetic evaluations
- conformation/ type traits
- produciton traits
- health traits
what drives genetic change
elite animals
performance index
optimized for general improvement of production, health, and conformation net merit (parent transmitting ability x economic value)= most common
targeting indexes
uses subset of traits to improve a targeted subject like cheese merit (emphasis on protein and fat %), fluid merit (emphasis on milk yield), grazing merit (emphasis on fertility), calving ability (emphasis on easy and alive calf birth), fertility index (emphasis on conception rate)
