CAL: Genetic Improvement

Question 1

What is the difference between genetic improvements and feeding/health changes impleemeneted on farm?

Answer 1

Genetic improvement cumulative over time, feedig and health changes not cumulative

Question 2

How can the levle of genetic prgress of a herd of given size be predicted?

Answer 2

R = S x h^2 
or
R = i x h^2 x SDp 
where
R = response
s = selection diffferential 
h^2 = heritability of the trait
i = selectino intensity 
SDp = std deviation of the pphenotype (sqrt of variance)

Question 3

Which aspect of genetic progress response equation can a breeder influence?

Answer 3

i (intensity of selecction pressure) by choosing proportion of gene pool picked to breed (ie top 10 vs top 100 animals)

Question 4

How can R be converted to an annual response?

Answer 4

R = per generation [= time mbetween same point in life cycle of offspring to parent]
to calculate annual response deivide R by generation interval

Question 5

how is amount of inbreeding calculateed?

Answer 5

delata F = 1/ (2NeL)
delta F = annual ^ in inbreeding
Ne = 4sd (where s and d are no. new sires and dams in a year)
L = generation interval

Question 6

Why is inbreeding bad?

Answer 6

• ^ risk autosomal recessive diseasse

- inbreeding depression (v fertility and hardiness, more important factor)