Animal Genetics. The body is made up of millions of tiny cells The contents of the cell is called...

Animal Animal GeneticsGenetics

Animal GeneticsAnimal Genetics

The body is made up of millions of tiny cellsThe body is made up of millions of tiny cells

The contents of the The contents of the cell is called cell is called protoplasm.protoplasm.

Animal cells are the smallest living things in the world. Animals are made purely of cells.

Animal GeneticsAnimal GeneticsThe Cell ComponentsThe Cell Components

NucleusNucleusGives cells the ability to grow, to digest food Gives cells the ability to grow, to digest food and to divide, contains chromosomes and to divide, contains chromosomes composed of genes.composed of genes.

CytoplasmCytoplasmGives the cell shape and contains components Gives the cell shape and contains components necessary for cell functions.necessary for cell functions.

Animal GeneticsAnimal GeneticsThe Cell ComponentsThe Cell Components

Cell MembraneCell MembraneOutside of the cell, allows only certain Outside of the cell, allows only certain materials to pass in and out of the cell.materials to pass in and out of the cell.


NucleusNucleusCytoplasmCytoplasm

Cell Cell MembraneMembrane

Animal GeneticsAnimal GeneticsCell DivisionCell Division

MitosisMitosisIncreases total number of cellsIncreases total number of cellsResults in animal growthResults in animal growthChromosomes pairs are duplicatedChromosomes pairs are duplicated

Animal GeneticsAnimal GeneticsCell DivisionCell Division

MeiosisMeiosisProduces gametesProduces gametesOnly have one-half the chromosomes of Only have one-half the chromosomes of normal cellsnormal cells

Animal GeneticsAnimal GeneticsChromosomesChromosomes

Rod shaped bodiesRod shaped bodies

Made of proteinsMade of proteins

Found in the Found in the nucleus of the cellnucleus of the cell

Exist in pairsExist in pairsExcept in gamete Except in gamete cells (single cells (single chromosome)chromosome)

Animal GeneticsAnimal GeneticsChromosomesChromosomes

The number of chromosome pairs differs The number of chromosome pairs differs for various animalsfor various animals

COWCOW 3030

HORSEHORSE 3333

PIGPIG 1919

CHICKENCHICKEN 66

HUMANHUMAN 2323

Animal GeneticsAnimal GeneticsGenesGenes

Located on chromosomesLocated on chromosomes

Thousands found in each animalThousands found in each animalInherited from parentsInherited from parents

Control inherited characteristicsControl inherited characteristicsCarcass traitsCarcass traits

Growth rateGrowth rate

Feed efficiencyFeed efficiency


Two types of inherited traitsTwo types of inherited traitsDominantDominant

RecessiveRecessive

Gene combinationsGene combinationsHeterozygousHeterozygous

HomozygousHomozygous


Dominant geneDominant geneHides the effect of another geneHides the effect of another gene

Polled condition in cattle is dominantPolled condition in cattle is dominant

The gene is represented by a capital letterThe gene is represented by a capital letter

Dominant Gene


Recessive geneRecessive geneGene that is hidden by anotherGene that is hidden by another

The gene is represented by a lower case The gene is represented by a lower case letterletter

Recessive Gene

Animal GeneticsAnimal GeneticsExamples of Dominant and Examples of Dominant and

Recessive GenesRecessive Genes

The dominant gene is written- PThe dominant gene is written- P

The recessive gene is written-pThe recessive gene is written-p

P= PolledP= Polled

p= hornedp= horned

Animal GeneticsAnimal GeneticsGene CombinationsGene Combinations

Homozygous gene pairHomozygous gene pairCarries two genes for a traitCarries two genes for a traitPolled cow might carry the gene PP Polled cow might carry the gene PP

Heterozygous gene pairHeterozygous gene pairCarries two different genes that affect a traitCarries two different genes that affect a traitPolled cows might carry a recessive gene Polled cows might carry a recessive gene with the dominant Ppwith the dominant Pp

Animal GeneticsAnimal GeneticsPredicting GeneticsPredicting Genetics

GenotypeGenotypeKind of gene pairs possessed Kind of gene pairs possessed

PhenotypePhenotypeThe physical appearance of an animalThe physical appearance of an animal

Punnett squares Punnett squares Are used to predict genotypes and Are used to predict genotypes and phenotypes of animalsphenotypes of animals

Animal GeneticsAnimal GeneticsPredicting the Polled Trait Using Predicting the Polled Trait Using

the Punnett Squarethe Punnett Square

P P

P PP PP

P PP PP

Polled DamPolled Dam

Po

lled

Sir

eP

oll

ed S

ire

Both parents are Both parents are dominant homozygous dominant homozygous for the polled traitfor the polled trait

All offspring will be All offspring will be dominant homozygous dominant homozygous for the polled traitfor the polled trait

Animal GeneticsAnimal GeneticsPredicting DwarfismPredicting Dwarfism

Using the Punnett SquareUsing the Punnett Square

N N

N NN NN

n Nn Nn

Normal DamNormal Dam

Car

rier

Sir

eC

arri

er S

ire

A A homozygous parent homozygous parent crossed with a crossed with a heterozygous parentheterozygous parent

Two offspring will be Two offspring will be homozygous for the normal homozygous for the normal trait and two offspring will trait and two offspring will be heterozygous (carriers be heterozygous (carriers of dwarfism)of dwarfism)

Animal GeneticsAnimal GeneticsPredicting Coat Color Using the Punnett SquarePredicting Coat Color Using the Punnett Square

B b

B BB Bb

b Bb bb

BW Dam (carrier)BW Dam (carrier)

BW

Sir

e (c

arri

er)

BW

Sir

e (c

arri

er) Both parents are Both parents are

heterozygous (carriers for heterozygous (carriers for the recessive coat color)the recessive coat color)

One offspring will be One offspring will be homozygous dominant, two homozygous dominant, two will be heterozygous, and will be heterozygous, and one offspring will be one offspring will be homozygous recessivehomozygous recessive

The normal coat color of Holstein cows is black and white (BW) the recessive color is red and white (RW)

Animal GeneticsAnimal GeneticsPredicting Coat Color Using the Punnett SquarePredicting Coat Color Using the Punnett Square

B b

b Bb bb

b Bb bb


RW

Sir

e R

W S

ire

A heterozygous parent A heterozygous parent (carrier) crossed with a (carrier) crossed with a recessive homozygous recessive homozygous parentparent

Two offspring will be Two offspring will be heterozygous (carriers) and heterozygous (carriers) and two offspring will be two offspring will be homozygous recessivehomozygous recessive


Animal GeneticsAnimal GeneticsWriting Genotypes and Phenotypes Using the Writing Genotypes and Phenotypes Using the

Punnett SquarePunnett Square

B b

b Bb bb

b Bb bb


RW

Sir

e R

W S

ire


GenotypesGenotypes• Bb and bbBb and bb

PhenotypesPhenotypes• Black and White CoatBlack and White Coat• Red and White CoatRed and White Coat


HeritabilityHeritability

Estimates the likelihood of a trait being Estimates the likelihood of a trait being passed on from the parent to the offspringpassed on from the parent to the offspring

Low heritabilityLow heritability

Slow herd improvementSlow herd improvement

High heritabilityHigh heritability

Faster herd improvementFaster herd improvement

Animal GeneticsAnimal GeneticsHeritabilityHeritability

Heritability for carcass traits are higher Heritability for carcass traits are higher than reproductive traitsthan reproductive traits

Low heritability is improved most through Low heritability is improved most through environmentenvironment

High heritability is improved most through High heritability is improved most through selective breeding and environmentselective breeding and environment

Estimates vary from 0 to 70%Estimates vary from 0 to 70%

Swine rates are usually lower than cattle

Animal GeneticsAnimal GeneticsHeritability EstimatesHeritability Estimates

Fertility 10%

Birth Weight 40%

Weaning Weight 25-30%

Yearling Weight 60%

Tenderness 60%

Animal Genetics. The body is made up of millions of tiny cells The contents of the cell is called...

Documents

Transcript of Animal Genetics. The body is made up of millions of tiny cells The contents of the cell is called...