Flashcards in sheep genetics lec 2 Deck (12):
What are the three options for genetic improvement?
1. remain with current stud
2. change ram source
3. change ram and purchase ewes
what are the advantagaes and disadvantages of staying with the same stud?
direction will follow stud’s breeding objective
what are the advantagaes and disadvantages of changing the ram source?
greater heterosis, potentially quicker rate of change
what are the advantagaes and disadvantages with changing ram source and purchasing ewes ?
rapid progress but costly
Ewes biggest change more quickly
what tools can you use in changing the ram source (5)?
Bloodline comparisons (ASBV and ESBV)
Stud’s breeding objective
Sire evaluation (merino select merino super sire using BV
On-farm trials (Benchmarking current ram source against one or more other ram sources)
Merino Select (ASBV database for merinos)
what is the relationship between FD, FW and $ income?
increase in FD = decrease in FW
decrease FD= increase $ income
what are the 4 things to consider when choosing bloodlines?
1. breeding objective (own and selected)
2. benchmark current lines
3. consider all traits
4. possible constraints
what are possible constraints when selecting bloodlines?
how much do bloodlines vary?
+2 to -3.5 micron
+15 to -20%
+18 to -$5
+ 19.4% to -12.4 % the average return being recorded
what is the CTSE and what is its purpose?
Breeding performance of sires measured by evaluating progeny
each sire mated to 50 ewes
what is the prupose of a link sire?
- 1 link sire/7sires
o Link sire already evaluated
o Act as genetic connection b/w years and site