Q: Which equation would you use to estimate the parent average for a trait in offspring?

$$\text{Parent Average} = \frac{P_{sire} + P_{dam}}{2}$$

Q: Which equation best represents the calculation of heterosis for a trait?

$$\text{Heterosis} = \text{Performance}_{\text{crossbred}} - \text{Parent Average}$$

Question 1

Which of the following best describes the purpose of a breeding pyramid in animal genetics?

Accepted Answer

To facilitate gene flow from nucleus herds to commercial production, allowing intense selection and expansion

Question 2

A breeder wants to increase the uniformity of a population by mating animals with similar phenotypes. Which mating system should they use?

Accepted Answer

Positive assortative mating

Question 3

Which equation would you use to estimate the parent average for a trait in offspring?

Accepted Answer

$$	ext{Parent Average} = \frac{P_{sire} + P_{dam}}{2}$$

Question 4

Which of the following is a primary benefit of using pedigree data in animal breeding?

Accepted Answer

It helps identify carriers of recessive or lethal mutations

Question 5

A population of Holstein cattle is being converted to Senepol through successive backcrossing while selecting for the SLICK hair coat gene. What is this process called?

Accepted Answer

Introgression

Question 6

Which mating strategy is most likely to increase heterosis (hybrid vigor) in offspring?

Accepted Answer

Cross-breeding

Question 7

A breeder uses a top cross to convert a population from breed A to breed B. After three generations of backcrossing to breed B, what percentage of breed B genetics would you expect in the offspring?

Accepted Answer

$$93.75\%$$

Question 8

Which of the following is NOT a reason to cross-breed animals?

Accepted Answer

To ensure all offspring are homozygous for every trait

Question 9

What is the expected outcome of negative assortative mating in a population?

Accepted Answer

Increased diversity and more outliers

Question 10

Which registry organization is responsible for maintaining breed standards and pedigrees for purebred dogs in the United States?

Accepted Answer

American Kennel Club

Question 11

A breeder wants to maintain a substantial degree of relationship to a noted ancestor while minimizing inbreeding. Which strategy should they use?

Accepted Answer

Line breeding

Question 12

Which equation best represents the calculation of heterosis for a trait?

Accepted Answer

$$	ext{Heterosis} = 	ext{Performance}_{	ext{crossbred}} - 	ext{Parent Average}$$

Question 13

Which mating system is most likely to be used to correct faults in a population?

Accepted Answer

Corrective mating

Question 14

In a breeding pyramid, which level has the most flexibility for different breeding goals?

Accepted Answer

Commercial production

Question 15

Which of the following best describes complementarity in crossbreeding?

Accepted Answer

Improvement in performance by combining strengths of different breeds

Question 16

A breeder uses a sire reference scheme in a co-op. What is the main advantage of this system?

Accepted Answer

It allows genetic links and comparison across different management systems

Question 17

Which of the following is a composite breed developed in Brazil for adaptation and production?

Accepted Answer

Girolando

Question 18

Which mating system involves mating unrelated individuals from different breeds?

Accepted Answer

Cross-breeding

Question 19

Which of the following is a plausible consequence of intense inbreeding in a population?

Accepted Answer

Increased risk of lethal mutations and reduced genetic diversity

Question 20

A breeder wants to introduce a single desirable gene from breed A into breed B through repeated backcrossing. Which process is most appropriate?

Accepted Answer

Introgression

Mating Systems and Genetic Improvement in Animal Breeding

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