Heritability and Repeatability

Question 1

phenotype

Answer 1

P = BV + D + I + Ep + Et

Question 2

heritability

Answer 2

relationship of difference in animal performance due to inheritance

Question 3

broad sense heritability

Answer 3

H^2 = r^2 P,G
strength of relationship between performance and genotypic value

Question 4

narrow sense heritability

Answer 4

h^2 = r^2 P,BV
strength of relationship between performance and breeding value

Question 5

high h^2

Answer 5

parent performance is good indicator of offspring performance
low environmental effect

Question 6

low h^2

Answer 6

parent performance is poor indicator of offspring performance
high environmental effect

Question 7

fitness trait

Answer 7

low heritability
ex. fertility and survivability

Question 8

production trait

Answer 8

moderate heritability
ex. milk production and growth rate

Question 9

terminal trait

Answer 9

high heritability
ex. carcass, skeletal, and mature weight

Question 10

h^2 alternate definition

Answer 10

h^2 = Va/Vp = Va/ Va + Vd + Vi + VEp + VEt

Question 11

management

Answer 11

high heritability changes BV quickly
low heritability can be managed with environment

Question 12

repeatability

Answer 12

r = r^2 p1,p2
strength of relationship between repeated records for a trait in a population

Question 13

high r

Answer 13

first record if good indicator of second record
low temporary environment effect

Question 14

low r

Answer 14

first record is poor indicator of second record
high temporary environment effect

Question 15

r^2 alternate definition

Answer 15

r = Va + Vd + Vi + VEp/ Va + Vd + Vi + VEp + VEt

Question 16

improving heritability and repeatability

Answer 16

uniform environment
accurate measurement
contemporary groups

Question 17

contemporary group

Answer 17

group of animals that experience a similar environment with respect to trait expression
P-Pcg = BV or PA + GCV + Ep + Et

Question 18

trait ratio

Answer 18

ratio of individuals performance to average performance
ratio 1 = Pi/Peg x 100
> 100: above average
< 100: below average