Reference no: EM132383897

ANSC 3500 Animal Breeding Assignment - Problem Set - Auburn University, USA

1. A dominant allele for a spinal abnormality in cattle is due to a mutation that occurs at the rate of 4.5 x 10^-5. The resulting calves die shortly after birth. In the Northeast, there are approximately 560,000 cows used for breeding each year. Because of the replacement of animals that occur each year, there are about 110 calves born to each 100 cows in a year. How many calves would you predict to show this defect in one year?

2. Assume: f(A to a) at rate 10^-5, and f(a to A) at rate 10^-8. What is the expected frequency of A at equilibrium?

3. Assume a population in equilibrium with the following phenotypic frequencies for the polled and horned gene in cattle (hh is the recessive genotype for the horned condition).

	Phenotypic frequencies
Polled	0.64
Horned	0.36

Calculate the gene and genotypic frequencies in the progeny if the parents are mated by negative assortative mating.

4. The gene frequency of A in population 1 is 0.75, and in population 2 is 0.50. There are 10,000 animals in population 1 and 2,500 animals are added to it from population 2. What is the gene frequency of A in the new enlarged population 1?

5. Assume the initial gene frequency of the dominant allele B for black pigs is 0.2 and that in the population:

f(BB) = 0.04

f(Bb) = 0.32

f(bb) = 0.64

A breeding program is then set up to eradicate the b allele by culling all red pigs each generation. The survivors are randomly mated.

a. Plot the frequency of B for increments of five generations given this breeding program.

b. How many generations are required to reduce f(b) from 0.8 to 0.005?

6. A large artificial insemination stud has just purchased a promising bull. Management is concerned, however, that the bull might be a carrier of osteopetrosis (marble bone disease), a recessive lethal condition.

Five percent of cows are thought to be carriers of the osteopetrosis allele.

a. A.I. matings to randomly selected cows have already produced 100 normal calves (and no homozygous recessive calves). What is management's level of confidence that the bull is not a carrier of the gene for osteopetrosis?

b. How many successful A.I. matings to randomly selected cows are required to be 99% sure the bull does not carry the osteopetrosis allele?

c. If the bull sires a calf with marble bone disease next year, what will be the management's level of confidence that the bull does not carry the osteopetrosis allele? What will be their level of confidence that he does carry the gene?

7. A young animal has the following weights:

70 lb at birth

580 lb at weaning

a. How many standard deviations above the mean is this animal for each trait given the information below?

	Birth Weight	Weaning Weight
μ (lb)	65	450
σ (lb2)	25	1600

Attachment:- Animal Breeding Assignment File.rar