Lecture 8 Flashcards
(17 cards)
How to improve the quantity and quality go wool production in a flock
Improve the genetics
What is the reason for slow progression in the past (3)
- Failure to adopt the best measurement and selection techniques
- Lack of a clear breeding objective
- Failure to use the best possible genetics
What is the genetic gain formula
Genetic gain = (selection differential x trait’s heritability)/generational interval
What do H2 values range between
0 to 1
What does a heritability estimate of 1 mean
All the variation for that trait is controlled by the environment
Define heritability
An estimate of the parents genetic contribution to the value of a particular trait in their progeny
Define selection differential
Superiority of the selected animals over the average
What does selection differential depend on
Variation available in the trait being selected and level of culling the breeder is able to use
What is required for maximising selection differential
Genetically superior animals in the flock to be identified correctly
What is the generation interval
Average age of parents when offspring are born
What is the calculation of performance
Genotype x environment
What does estimating breeding values (EBV) provide
Accurate estimate of the genetic merit of an animal
What does selection to improve productivity require
A number of traits to be considered
What does the selection index combine
The genetic merit of an animal for a number of traits into a single figure
What can the selection index be used to compare
The genetic value of individual animals for all those traits combined
What is the micron premium index used for
Method of valuing the price premium associated with a change in fibre diameter
What are the wool breeding programme objectives (5)
- Decrease FD
- Increase GFW
- Improve staple length
- Decrease body wrinkle
- Maintain wool quality
