genetics 4: practical considerations

Question 1

how is breeding managed in domestic animals

Answer 1

• able to select for traits we desire in offspring or
• select against a negative trait
• requires assessment and measurement of the extent to which certain traits have been inherited from their sire and dam

Question 2

give examples of things we assess when selectively breeding domestic animals

Answer 2

• milk production in cows
• growth rate in pigs
• fleece quality in sheep
• hip and elbow dysplasia scores in dogs
• thoroughbred galloping speed

Question 3

what is heritability

Answer 3

• the extent to which offspring resemble their parents or
• the proportion of pheotypic superiority of the parents that is seen in their offspring
• if h2=1 all the superiority of the parents is passed on to the offspring
• if h2=0 none of the superiority of the parents is passed on to the offspring

Question 4

what is predicted transmitting ability

Answer 4

the amount of a particular trait an animal is predicted to pass on to its progeny
- average of the expected improvement in the daighter
- expressed relative to the average for that breed (the genetic base)
- updated every year
- identification of superior animals