animal genetics. the body is made up of millions of tiny cells the contents of the cell is called...
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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.
Animal GeneticsAnimal Genetics
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
Animal GeneticsAnimal GeneticsGenesGenes
Two types of inherited traitsTwo types of inherited traitsDominantDominant
RecessiveRecessive
Gene combinationsGene combinationsHeterozygousHeterozygous
HomozygousHomozygous
Animal GeneticsAnimal GeneticsGenesGenes
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
Animal GeneticsAnimal GeneticsGenesGenes
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
BW Dam (carrier)BW Dam (carrier)
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
The normal coat color of Holstein cows is black and white (BW) the recessive color is red and white (RW)
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
BW Dam (carrier)BW Dam (carrier)
RW
Sir
e R
W S
ire
The normal coat color of Holstein cows is black and white (BW) the recessive color is red and white (RW)
GenotypesGenotypes• Bb and bbBb and bb
PhenotypesPhenotypes• Black and White CoatBlack and White Coat• Red and White CoatRed and White Coat
Animal GeneticsAnimal Genetics
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%