Exam 3 Flashcards
What are causes of correlated response?
Linkage
Pleiotropy
What is linkage?
Major genes affecting two traits that are closely linked
Why is linkage considered temporary?
Because of recombination
What is pleiotropy?
Gene influences more than one trait
What is pleiotropy a major cause of?
Halothane gene–HYPP
What do correlated response to selection result from?
Genetic correlations between traits
What are the 3 types of correlation?
Genetic
Phenotypic
Environmental
What does genetic correlation measure?
The relative importance of pleiotropic effects on 2 traits
What is the symbol for genetic correlation?
r_BVx, BVy
What does phenotypic correlation measure?
The strength of the relationship between performance of one trait and performance of another
What is the symbol for phenotypic correlation?
r_Pbw, Pyw
What is environmental correlation a measure of?
The strength of the relationship between environmental effects of one trait and environmental effects of another
What is the symbol for environmental correlation?
r_Ebw, Eyw
What are higher weaning and yearling weights generally associated with?
Higher birth weights
What are higher growth rates generally associated with?
Larger scrotal circumferences and ribeye areas
What are higher growth EPDs generally associated with?
Lower maternal milk EPDs
What are higher maternal milk EPDs generally associated with?
Higher marbling in progeny
What are factors affecting correlated response?
Correlation between traits h^2 i σp (phenotypic variation) L