In a cross of two purebreeding lines of dairy cattle with di

In a cross of two pure-breeding lines of dairy cattle with different amounts of milk production, the variance in volume of milk production in the F1 generation is 2.3 gallons per day, and the variance in self-crossed F2 generation is 4.7 gallons per day. What is the broad sense heritability of the trait? 0.5 2.4 4.7 1.9 2.3

Solution

A). 0.5

Broad sense heritability is the ratio of genotypic variance to the total phenotypic variance (includes the additive, dominant and epistatic variances).

H2 = Var (G)/ Var (P).

Genotypic variance (Var (G)) is = 4.7 - 2.3 = 2.3

The phenotypic variance (Var (P)) is = 4.7

H2 = 2.3/4.7 = 0.489 or approximately equal to 0.5