cross breeding abg
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CrossbreedingCrossbreeding
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Cross BreedingCross Breeding It is the breeding between different animal Species,
breed, strains or lines. It is mostly used to combinethe desired trait in the parents in the offspring andto explore a phenomenon called as Hybrid vigor (Heterosis).
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Crossing SpeciesCrossing Species There are many factors to consider in crossing
species such as:
Species being crossed should belong to the sametaxonomic genera or family.
Should have the same number of chromosomes Most offsprings do not survive. Those that survive and
reach sexual maturity are sterile
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Examples of Species crossesExamples of Species crosses
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Examples of Species crossesExamples of Species crosses
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Examples of Species crossesExamples of Species crosses
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Examples of Species crossesExamples of Species crosses
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Examples of Species crossesExamples of Species crosses
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Examples of Species crossesExamples of Species crosses
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Examples of Species crossesExamples of Species crosses
Ass x Zebra = Asbra
Horse x Zebra = Zebroid
Horse x Ass = Mule
Cattle x buffalo = Beefalo
Cattle x Yak = Zoo/Zom
Mithun x Cattle = Jatsha
Sheep x Goat = Geep
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Crossing BreedsCrossing Breeds This is an important breeding system to produce
new breeds.
Local JerseyX
Crossbred (50% J:50 % L)F1
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Examples of new breedsExamples of new breeds
Scottish Blackface x Bluefaced Leicester sheep = Grey face
Karan x Brown Swiss = Karan Swiss
Karan x Hostein Fresien = Karan Fries
Jamaican cattle x Jersey = Jamaican Hope
Australian Zebu x Jersey = Australian Milking Zebu
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Breeding options after F1Breeding options after F1 Breeders are usually concerned about what to do
after the F1 generation
Some of the breeding systems which could beused are as follows.
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InterInter--se matingse mating
In this kind of breeding system, the F1 females aremated with F1 males of the same breed.
50 % J X 50 % J
50 % J
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BackcrossingBackcrossing
This is a system where a crossbred offspring isbred back to one of its parent breed which are
usually purebred.
J LX
50 % J XJ/L
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Crisscrossing:Crisscrossing: Here the F1 is mated to A and B
alternatively.
J LX
50 % J
50 % L
XJ
75 % JX
L
37.5% J: 62.5 L
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Rotational Crossing:Rotational Crossing:
Here, different breeds of sires are used in
a rotation. It is usually used in pigbreeding.
A B
C XX
D X Y
E X Z
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Grading upGrading up It is a system where one breed is changed
(graded up) to another by continued crossing.
Usually, native breeds are graded up to an
improved breed.
Usually, 4 generation of crossing with an
improved or registered breed is considered aspurebred status.
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Grading upGrading up
Siri
JS
xbredMithun
Jersey
JSM
xbred
JSM
xbred
JSM
xbred
JSM
xbred
Jersey
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Learning guideLearning guide1. What is cross breeding?
2. What factors should be considered for species
crossing?3. What is inter-se-mating?
4. What would happen in back crossing?
5. How can the breed be upgraded?