Exam 2 Flashcards
2 Breed specific AxB
Individual HV: 100% Maternal HV: 0% Complementarity: full Replacement females: no Management Difficulty: low Uniformity of Progeny: high
3 breed specific C x AB
Individual HV: 100% Maternal HV: 100% Complementarity: full Replacement females: no Management Difficulty: low Uniformity of Progeny: high
Backcross
Individual HV: 50% Maternal HV: 100% Complementarity: some Replacement females: no Management Difficulty: low Uniformity of Progeny: high
2 breed rotation
Individual HV: 67% Maternal HV: 67% Complementarity: none Replacement females: yes Management Difficulty: medium Uniformity of Progeny: low
3 breed rotation
Individual HV: 86% Maternal HV: 86% Complementarity: none Replacement females: yes Management Difficulty: high Uniformity of Progeny: low
Composite ⅜ A - ⅝ B
Individual HV: variable 40-80% Maternal HV: variable 40-80% Complementarity: none Replacement females: yes Management Difficulty: low Uniformity of Progeny: high
3 breed rotaterminal
Individual HV: 100% Maternal HV: 67% Complementarity: full Replacement females: yes Management Difficulty: high Uniformity of Progeny: medium
Half sib mating
R= .25
F=.125
Full sib mating
R= .5 F= .25
Sire x Daughter mating
R= .5 F= .25
Inbreeding
The mating of relatives
Common ancestor
An ancestor common to more than one individual
Prepotency
The ability of an individual to produce progeny whose performance is especially is especially like its own and or is especially uniform
Inbreeding depression
The reverse of hybrid vigor- a decrease i the performance of inbreds, most noticeably in traits like fertility and survivability
Hybrid vigor
An increase in the performance of hybrids over that of purebreds, most noticeably in traits like fertility and survivability
Fitness trait
The ability of an individual and its corresponding phenotype and genotype to contribute offspring to the next generation
Inbreeding coefficient
A measure of the level of inbreeding in an individual
Identical by decent
Two genes are identical by descent if they are copies of a single ancestral gene
Alike in state
Genes that are alike in state function the same and have exactly or almost exactly the same chemical structure
Wright’s Coefficient
A measure of pedigree relationship
Base population
The population of animals whose parents are either unknown or ignored for the purposes of inbreeding or relationship calculation
Linebreeding
The mating of individuals within a particular line, designed to maintain a substantial degree of relationship to a highly regarded ancestor or group of ancestors without causing high levels of inbreeding
Pure breeding
The mating of purebreds of the same breed
Outbreeding
The mating of unrelated individuals
Individual hybrid vigor
Hybrid vigor for the direct component of a trait
Maternal Hybrid Vigor
Hybrid vigor for the maternal component of a trait
Paternal Hybrid Vigor
Hybrid vigor paternal component of a trait
F1 Hybrid Vigor
Amount of HV obtainable in the first cross individuals; maximum hybrid vigor
Retained hybrid vigor
Hybrid vigor remaining in later generations of hybrids
Recombination loss
A loss in gene combination value caused by the gradual breaking up of favorable epistatic blocks of linked loci in advanced generations of certain hybrids
Backcross 1
The first generation of crosses between hybrids and purebreds of a parent breed or line
Degree of backcrossing
The proportional amount of backcrossing involved in mating
Backcrossing
The mating of a hybrid to a purebred of a parent Bree or line.
The mating of an individual to any other individual with which it has one or more ancestral breed or lines in common
Cross breeding system
A mating system that uses cross breeding to maintain a desirable level of hybrid vigor and breed complementarity
Sire x Dam complementarity
The classic form of complementarity produced by mating sires strong in paternal traits to dams strong in maternal traits. Offspring inherit superior market characteristics from their sires and benefit from the maternal environment provided by their dams
Hybrid seedstock complementarity
The form of complementarity produced by crossing genetically divers breeds to create hybrid breeding animals with a desirable combination of breeding values
Rotational cross breeding system
A cross breeding system in which generations of females are “rotated” among sire breeds in such a way that they are mated t sires whose breed composition is most different from their own
Spatial rotation
A rotational cross breeding system in which all sire breeds are used simultaneously- they are spatially separated. Replacement females leave the location of their birth to be mated to sires with different breed composition
Rotation in Time
A rotational cross breeding system in which sire breeds are not used simultaneously, but are introduced in sequence
Terminal Sire Crossbreeding System
A crossbreeding system in which maternal-breed females are mated to paternal-breed sires to efficiently produce progeny that are especially desirable from a market standpoint. Not kept as replacements
Static Terminal System
A terminal sire crossbreeding system in which replacement females are either purchased or produced from separate purebred populations within the system
Rotational terminal system
A crossbreeding system combining a maternal rotation for producing replacement females with terminal sires for producing market offspring
Composite Animals
A hybrid with at least two and typically more breeds in its background. Expected to be bred to their own kind, retaining a level of hybrid vigor normally associated with traditional crossbreeding system
Composite Breed
A breed made up of two or more component breeds and designed to benefit from hybrid vigor without crossing with other breeds
Pure Composite System
A mating system limited to matings within a single composite breed
Composite/Terminal System
A crossbreeding system combining a maternal composite breed for producing replacement females with terminal sires for producing market offspring
Effective pop size
the size of a population as reflected by its rate of inbreeding
