1. The mean adult weight of your pig population is 720 lbs. P1 is an outstanding pig and has an adult weight of 650 lbs. After carrying out matings between P1 with any sows from your population, you obtained a new population (i.e. progeny of P1). The mean adult weight of the progeny population is only 780  lbs.

a. What is your estimate of P1’s breeding value?

 

 

b. Assuming there is no dominance or epistasis at the loci that influence adult weight, calculate P1’s genotypic value (G), environmental effect (E), and gene combination value (GCV)

 

2. You measure the body weight of a cattle population. The variance of body weight is 50 lbs^2 and the variance caused by permanent environmental effect is 10 lbs^2 . The correlation coefficient between body weight and breeding value is 0.4. The repeatability of body weight is 0.8.

a. What is the narrow-sense heritability h^2?

 

 

b. What is the variance of breeding values?

 

 

c. What is the variance of gene combination values?

5. Consider two populations of lambs. Lambs from population 1 are highly inbred and are raised in a uniform environment. Their average weight at six weeks is 18 lbs. and the variance is 2.6 lbs². Population 2 is genetically heterogeneous and is raised in the same uniform environment as population 1. Their average weight at six weeks is 18 lbs. and variance is 8.2 lbs².

a) What is V_e for weight?

b) What is V_g in population 1? In population 2?

c) What is the broad sense heritability in population 2?

Hey guys! I'm a little stuck with this question, with calculating the total genetic variance I'm not sure whether my answers are correct.

(VG = VA + VD = VI

(Broad sense heritability) H2 = VG/VP

(Narrow Sense heritability) h2 = VA/VP

(Response to Selection) R = h2 x s

A plant breeder has determined the following variances for yield of corn:

Total phenotypic variance 100

Additive genetic variance 30

Dominance genetic variance 50

Environmental variance 20

Assume that there is no genetic-environmental interaction or other variances. a) Calculate the total genetic variance.

b) Calculate the broad-sense heritability indicated by these results.

c) Calculate the narrow-sense heritability indicated by these results.

d) The breeder wishes to improve yield. The average yield in the starting population is 400. Plants with an average yield of 500 are selected for breeding. What is the expected average yield among the offspring of the selected plants?

a. How do you estimate the variance (s2 ) of a behavioral trait in a population? b. What is the definition of heritability (strict/statistical)? c. What is one way to estimate heritability? d. How do you estimate the influence of “environment” on the variance of a trait in a population?