Systems of Breeding Flashcards
—— ——- is the most common
disqualification
in Purebred Breeding
Both parents must have been a —- in Purebred Breeding
Not necessarily better than non-purebred
Color markings
Purebred
Purebred Animal
- Undesirable recessive characteristics may appear
because of the ———– of the gene - The average purebred animal is generally better
than the average ———– animal
non-purebred
homozygosity
non-purebred
———– Mating of related animals
——– ——– - most intensive
3. ———— - distantly related animals
4. Increases the genetic purity of the stock produced.
5. Undesirable and desirable genes become grouped together in the
offspring with greater frequency and more visible.
Inbreeding
Close breeding
Linebreeding
Mating of animals of different families within the same breed
Bring into the breeding program traits that are desirable but
not present in the original animals
is mating animals from two different lines of breeding within a breed
Outcrossing
Linecrossing
Mating of purebred sires to grade females
2. A grade animal in any animal not eligible for
3. Some breed associations do permit the offspring of
grading up to be .
Grading up
registry
registered
Mating of two animals from different breeds
2. Offspring is a
—–
3. Superior traits from crossbreeding are called ———–
4. Animals selected for use in a crossbreeding program
must have the desired traits
Crossbreeding
hybrid
hybrid vigor or heterosis
———— ———— - base on own performance records, most simple.
————- ————- - Base on the average performance of their own family,
more complicated, more expensive, used if the trait has low heritability.
Individual Selection
Family Selection
Family Selection
- one trait at a time
- – base on a pre-determined level of
performance - – each trait is weighted by a coefficient
Tandem Selection
Independent culling level
Selection index
Increases homozygosity (uniformity => like gametes, like individuals)
Inbreeding
Disadvantages of Inbreeding –
1) inbreeding exposes
2) inbreeding depression –reduced
–high risk (complete lines can be lost)
deleterious genes.
performance due to increased
homozygosity, exposing genes with
negative effects
Non-Inbred vs. Inbred Crested Wood Partridges
• 8% reduction in
• 10% reduction in
• 20% reduction in
• Non-inbred birds have –% —– medical
notes than their inbred counterparts.
egg volume
egg weight
hatchability rate
41% fewer
mating system design to maintain a
high degree of relatedness of
descendants to a particular ancestor
Linebreeding
crossing of animals from different
breeds
Crossbreeding
subpopulation of a species inter
se mated with the objective of
maintaining particular characteristics
that define the group
Breed
Over time breeds come to
represent different reservoirs of
genes:
Different alleles
Different frequency
Reasons for Crossbreeding
1)
2)
3) –
4)
Complementarity
Methods of migration of new genotypes
Creating synthetic breeds
Rapid Change in Performance
Critical value for .05 level of significance:
The value expected to be
exceeded 5% of the time by —— ——- given the hypothesis
is true.
by
chance alone
Critical values for the .01 level are ——- ——– than those for .05:
A larger C.V. means a greater ———
between expected and observed is required
to reject the hypothesis.
Fewer true hypotheses will be rejected by chance when testing at … versus ..
Conversely, a greater number of false
hypotheses will be accepted.
always larger
discrepancy
.01
.05
Two Basic Systems in Breeding System
Crossbreeding
Purebreeding
System used depends on:
Kind of livestock
Size of the herd
Amount of money available
Goal of the farmer or rancher
Straight Breeding:
Purebred breeding
Inbreeding
Outcrossing
Grading Up
Cross breeding
Two way cross
Three way cross
Four way cross
Rotation breeding
Methods of Selection base on Records
Individual, Family, and Sib Selection
Selecrion by Progeny Test
Selection Procedure
Simultaneous Improvement of Traits
Tandem Method
Independent Culling Level
Selection Index
Inbreeding depression
Reduction in fitness in inbred individuals
• JS
• AS
• MA
• SD
• FF
• G
• PD
• DS
• RTES
• ME
Juvenile survival • Adult survival
Mate Acquisition • Social Dominance
Fertility and Fecundity • Growth
Proper development• Disease resistance
• Resistance to environmental stresses
• Metabolic efficiency
combining
breeds then inter se mating to form a new
breed
Creating Synthetic breeds
combine breeds to take advantage of the best characteristics for both
Complementarity
Subpopulation of a species inter se mated with the objective of maintaining particular characteristics that define the group.
Crossbreeding
