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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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?

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Cross Breeding Abg