Close Breeding Abg

7/30/2019 Close Breeding Abg

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BreedingBreeding


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BreedingBreeding

Breeding is the mating of the potential parentsBreeding is the mating of the potential parents

selected naturally or artificially from the herdselected naturally or artificially from the herd

or flock.or flock.


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Difference in Breeding MethodsDifference in Breeding Methods

Natural Breeding Artificial Breeding/Insemination

This is the type where the animalsare mated in natural state

This is the type where the cows areinseminated with the semencollected from the sire

The cost and hassle of maintaining This is cheaper and less labour

There is chances of transmission ofvenereal diseases

No chances of transmission due tolack of body contact

The bull service is limited to just itslife span

The semen can be used long afterthe bull is dead

The impregnation of cow is one perejaculate

With single ejaculate, we caninseminate hundred of cows

Low conception rate due todeposition of semen in the vagina

High conception rate due todeposition of semen in the cervix


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Breeding Tools / TypesBreeding Tools / Types

Two general types of breedingTwo general types of breeding

Close breedingClose breeding

Out breedingOut breeding


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InbreedingInbreeding

It is the mating of animals that are closely related to eachIt is the mating of animals that are closely related to each

other than the average of the population. In other words,other than the average of the population. In other words,it is the mating of animals that have one or moreit is the mating of animals that have one or morecommon ancestors.common ancestors. EgEg. Mating of Sire to its female. Mating of Sire to its femaleoffs rin soffs rin s..

X

A

B

A

C


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InbreedingInbreeding

The degree of inbreeding will be determined by theThe degree of inbreeding will be determined by the

closeness of the relationship between the parents and iscloseness of the relationship between the parents and isexpressed as inbreeding coefficient.expressed as inbreeding coefficient.


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Inbreeding CoefficientInbreeding Coefficient

In a population, inbreeding coefficient can be calculatedIn a population, inbreeding coefficient can be calculatedas.as.

F =F = 11

2Ne2Ne

WhereWhere F = Increase in inbreeding per generation,F = Increase in inbreeding per generation, Ne = EffectiveNe = EffectivePopulation SizePopulation Size


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Effective Population SizeEffective Population Size

FormulaFormula

NeNe == 4NmNf4NmNf

Nm +Nm + NfNf

Where Ne = effective population size, NmWhere Ne = effective population size, Nm = the number of males in= the number of males ina population,a population, NfNf = number of females in the population= number of females in the population


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InbreedingInbreeding ExcerciseExcercise

What is the inbreeding coefficient of 125 femaleWhat is the inbreeding coefficient of 125 female

population withpopulation with 1212 breeding bulls in one generation?breeding bulls in one generation?


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Effect of inbreedingEffect of inbreeding

Inbreeding reduces the number of gene pairs that areInbreeding reduces the number of gene pairs that are

heterozygous in the population and increases theheterozygous in the population and increases theproportion of gene pairs that are homozygous,proportion of gene pairs that are homozygous,regardless of whether they are good or bad.regardless of whether they are good or bad.

This system leads to a phenomenon called asThis system leads to a phenomenon called asInbreeding depression that throw up many physicalInbreeding depression that throw up many physicalabnormalities such as dwarfism, undershot jaws, etcabnormalities such as dwarfism, undershot jaws, etc

Decline in the performance of the animals especially inDecline in the performance of the animals especially intraits like fertility, survival and size.traits like fertility, survival and size.


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How to avoid inbreedingHow to avoid inbreeding

In a herd, it is essential to change the Sire every 3 yearsIn a herd, it is essential to change the Sire every 3 years

to avoid inbreedingto avoid inbreeding


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Line Breeding.Line Breeding.

It is another form of inbreeding.It is another form of inbreeding.

It is the breeding of animals to the same ancestor andIt is the breeding of animals to the same ancestor andmainly carried out to develop pure breeds with certainmainly carried out to develop pure breeds with certaindesired qualities/traits.desired qualities/traits.

X

B

A

E

C

D


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Learning guideLearning guide What is inbreeding?What is inbreeding?

What are the effects of inbreeding?What are the effects of inbreeding? Estimate the inbreeding coefficient?Estimate the inbreeding coefficient?

What strategies would you employ to avoidWhat strategies would you employ to avoid

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Close Breeding Abg