Shared Flashcard Set

Details

Animal Breeding
Chapter 18
24
Agriculture
Undergraduate 4
12/18/2008

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Cards

Term

 

Why is genetic likeness

a reason for correlation in P*?

Definition

 

Animals that produce P1 and P2

share genes and their effects, this causes a contribution of Rh2.

Term

 

"Correlation among P*"

 

What causes correlation in P1 and P2?

Definition

 

 

 

1) shared genetic information

 

2) environment

Term

 

 

What makes pairs of obervations correlated as compared to random pairs of observations?

 

List two examples

Definition

 

 

 

1) Repeated records on cows

 

2) Records on full sibs

Term

 

 

For each unit increase/decrease in _1_, we

predict the average increase/decrease in _2_.

Definition

 

 

1) P* (phenotypic information)

 

2) A (breeding value of animal)

Term

 

 

What type of information do we use to predict

breeding value of an animal?

Definition

 

 

 

phenotypic information

Term

 

 

 

What do we use to predict what happens

on the average?

Definition

 

 

 

Regression

Term

 

 

 

"Level of accuracy" is used to do what?

Definition

 

 

 

Evaluate how we use different information to

give us response to selection

Term

 

 

 

Define "Level of accuracy"

Definition

 

 

 

Correlation between the true breeding value

and the predicted breeding value

Term

 

 

 

Name traits that we wish to improve but

cannot measure on live animals

Definition

 

 

 

carcass quality

 

carcass lean yield

Term

 

 

 

Name traits that we wish to improve but

cannot measure on both sexes.

Definition

 

 

 

litter size

 

milk production

 

egg production

Term

 

 

 

Name traits expressed by an animal that

can be measured more than once (repeated

over the animal's lifetime)

Definition

 

 

 

litter size

 

lactation yield

 

racing time

Term

 

 

 

Name traits that are only expressed

once by an animal

Definition

 

 

birth weight

 

yearling weight

 

age at puberty

 

backfat at 250 lbs

Term

 

 

 

Give the equation for calculating regression

Definition

 

             bA.P* =  ________n R h2_______

                          1+(n-1) corr. among P*

 

n = # of records

 

R = genetic relationship between animal's

breeding value on phenotypic info known

 

h2 = heritability

 

Term

 

 

 

Give the equation for calulating accuracy

Definition

 

rA.P* = [bA.P* x R]1/2

 

n = # of records

 

R = genetic relationship between animal's

breeding value on phenotypic info known

 

h2 = heritability

 

Term

 

 

Explain two ways in which breeding value

can be calculated

Definition

 

 

1) sum of individual (additive) gene effects

 

2) twice the difference between mean of a large

number of progeny from large number of mates,

and mean of population

Term

 

 

Why is environmental likeness a reason

for correlation in P*?

Definition

 

 

something that is common to both records, but

not to other records

Term

 

 

 Define "permanent environmental variance"

 

Definition

 

environmental effect that

is "permanent" throughout an animal's life,

affecting each production record

 

labeled as Ep2

 

total correlation is h2 + Ep2

 

total correlation can also be called

"repeatability" and the symbol "re" can be used

Term

 

 

Define "common environmental variance"

Definition

 

 

 

environmental effect that is common for all

members of a family

 

labeled as c2

 

for full-sib family: .5 h2 + c2

for half-sib family: .25 h2 + c2

Term

 

The dairy evaluations regularly solve how many simultaneous equations?

 

                         A) 30,000

                         B) 300,000

                         C) 3,000,000

                         D) 30,000,000+

Definition

 

 

 

D) 30,000,000+

Term

 

 

Define E.R.P.A.

Definition

 

 

Estimated Relative Producing Ability

 

- predicted deviation for expected

future performance

Term

 

 Calculate the regression coefficient and accuracy

for a sow, based on her 3 records (she has

produced 3 litters)

 

                    h2=.12

                    re=.26

                    c2=.09 for littermates

                    c2=0 for non-littermates

Definition

 

             bA.P* =  ________n R h2_______

                          1+(n-1) corr. among P*

 

=  _(3)(1)(.12)_ =0.24

 1+(3-1)(.26)       

 

 rA.P* = [bA.P* x R]1/2

 

= [(0.24)(1)]1/2 = 0.49

Term

 

List four benefits of using multiple records

Definition

 

  •  inexpensive
  • overcome effects of temporary environment
  • useful when traits have low h2 and re
  • increases generation length
Term

 

 

List benefits of using progeny data

Definition
  • useful for traits expressed in only one sex
  • useful for traits with low h2
  • useful for carcass traits
  • most accurate method for predicting BV
  • reduces intensity: do not progeny test all animals
  • increases generation length
  • need to balance accuracy, intensit and generation length
Term

 

 

List benefits of using sib data

Definition
  • useful for traits expressed in only one sex
  • useful for carcass traits
  • more helpful to lower h2
  • does not increase generation length
  • reduce intensity in the case of slaughtering sibs for carcass data
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