Mating Strategies and Heterosis Flashcards
Define crossbreeding.
Mating of individuals from different breeds or lines
What are the four benefits/advantages of crossbreeding?
- complementarity
- migration of new genotypes
- synthetic (composite) breeds
- rapid change in performance
Are heterosis and hybrid vigor the same?
Yes!!
Define heterosis/hybrid vigor.
The increase in the performance of crosses (hybrids) between diverse parents such that the progeny is superior to the parent average.
What are the three mechanisms of heterosis?
- dominance
- overdominance
- epistasis
True or False. Heterosis can be inherited.
False!
From the breeding equation, what part contributes to heterosis?
GCV
Which gains more from heterosis? Carcass or reproductive traits?
Overall, low heritable traits have great heterosis. As Reproductive traits are lowly heritable, they have a higher heterosis.
Define Reciprocal Cross
A pair of crosses between a male of one breed and a female of another breed, and vice versa.
What are the three types of heterosis?
- maternal
- paternal
- individual
True or False. If the parents are purebred, they will have maternal and paternal effects on the offspring.
False
Define individual heterosis.
The advantage of the crossbred individual relative to the average of the purebred individuals.
Define Heterosis Retention.
Heterosis remaining in generations after F1.
When is heterosis maximized?
In F1 crosses.
Define mating decisions.
Which male breeds to which female.
