ANSC 202 Exam 1

What are the major 5 species

1. Cow

2. Pig

3. Sheep

4. Goat

5. Horse

What are some of the barriers to domestication?

• Diet

• Growth Rate

• Issues with Captive Breeding

• Nasty Disposition

• Tendency to Panic

• Social Structure

What is the Asiatic Mouflon an ancestor of?

Sheep

What is the Bezoar an ancestor of?

Goat

What is the Aurochs an ancestor of?

Cattle

What is the Wild boar an ancestor of?

Pig

What are Wild horses an ancestor of?

Horses

What are the uses of large domestic animals?

• Meat

• Milk products

• Fertilizer

• Land transport

• Leather

• Military assault vehicles

• Plow traction

• Fiber (wool, hair)

What is a breed?

A group of domesticated animals sharing common ancestry and distinctive

characteristics (e.g., conformation, color, or performance ability) that are consistently

transmitted to their offspring because of selective breeding. These traits are generally

documented and maintained by a breed registry

What is a standardbred?

n the 18th and 19th centuries, animals recorded in a breed registry based on having reached a

specific standard

What is a purebred?

An animal whose parents and ancestors belong to the same recognized breed.

Their lineage is recorded in a closed studbook or registry.

What is a crossbred?

An animal resulting from the intentional mating of purebred parents from two

different breeds

What is a landrace?

A population of domesticated animals that has developed over time through natural

selection and traditional management within a specific local environment

Who is robert bakewell?

Pioneer of systematic animal breeding

• Carefully selected males and females to breed

• Advocated use of inbreeding to create lines

that bred truly

• Used progeny tests for performance-based

selection

• Developed the New Leicester sheep breed from

the Lincoln Longwool

Who is Sir John Sebright?

Theoretical influence on breed

development

• 1809 essay, "The Art of Improving Breeds of

Domestic Animals"

• Recognized that laws drove inheritance, but

it was not critical to know them to use

selection

• Selection of males and females to breed

together considering each other's merits and

defects

• Supported ancestry breeding over progeny

testing

Who is Gregor Mendel?

The father of modern genetics

1. Innately curious and observant

2. Mendel was the first to take a quantitative,

scientific approach to the study of heredity.

3. Began his studies using mice

4. Switched to studying peas from 1856-1863

5. Kept careful records of 7 different traits

What is partial inheritance?

• Used pure-breeding lines for specific traits

• White flowers could be produced by crossing

two purple flowers, if the purple flowers had

at least one white flowered parent.

• Evidence that the factor for white flowers has

not blended irreversibly with the factor for

purple flowers.

• In particulate inheritance, heredity is the

product of discrete factors that control

individual traits.

What is a locus?

A specific position along a chromosome

What is an allele?

An alternative variant of a locus that arises by mutation

What is a wild-type allele?

The most common allelic form in a natural population

What does homozygous mean?

If both alleles of a particular gene are identical

What does heterozygous mean?

If the alleles are different from each other

What is hemizygous?

If only one copy of a gene is present

What is a genotype?

The complete set of alleles in an individual

What is a phenotype?

The visible or detectable effects of alleles on the structure or function of an individual

What was Mendel's First Law

The Law of Equal Segregation

-Offspring inherit one allele from each parent for a

trait, and no allele is favored or has an advantage

over the others

-Diploid individuals inherit two alleles for each

trait, with one allele on each member of a pair of

homologous chromosomes

-During gamete formation, the two alleles at a

gene locus separate and segregate from each

other

-Each gamete has an equal probability of

containing either allele

What was Mendel's Third Law?

The Law of Dominance

-For the two alleles of a gene, the dominant

allele is always expressed because it masks

the recessive allele

-Recessive traits are only seen when both

alleles are recessive

What is a punnett square?

• Matrix to predict all possible genotypes of

offspring

• If dominance relationship known, can predict

phenotype

What is haplosufficiency?

the wild-type allele

What is haploinsufficiency?

a genetic condition where a single functional copy of a gene is not enough to maintain normal function, causing a dominant disease or mutant phenotype

What is the structure of Livestock Industries?

Elite seedstock

Multiplier seedstock

Commercial producer

Growing & feeding enterprises

Who was King James 1

King James I imported Arabian stallions around 1616

-Any horse bred to an Arabian was "thoroughly bred"

-Thoroughbreds were tested for stamina by racing them at

Newmarket

What are the rules for the general stud book?

• Founded by James Weatherby in 1791 who was the keeper of the Match Book

• Early volumes retrospectively recorded pedigrees back to the late 1600s from private records

• Remains the official record of Thoroughbred pedigrees owned by Weatherbys

• Horses can be traced by direct descent to the original foundation bloodstock of the breed

• Inclusion in the studbook requires that a horse descend entirely through registered parents

• Arabians continued to be registered in the GSB until the 1960s

• The Thoroughbred became a purebred breed and has been genetically closed since the 18th century

• The GSB describes the biological and legal definition of a Thoroughbred

• The Jersey test

What are the rules for the american stud book?

• First published in 1868 in the United States by Sanders Bruce

• In 1896 ownership transferred to The Jockey Club

• Registers Thoroughbreds foaled in North America or imported from approved foreign stud books

• Regulates naming, parentage verification, ownership, transfers, exports and imports

What are the British Beef Cattle breeds?

• Angus

• Hereford

• Polled Hereford

• Red Angus

• Shorthorn

What is the angus?

Most Annual Registrations in US

• Originates from Aberdeen-Angus counties in

Scotland

• 300,000+ registrations in 2025

• US Herd book first published in 1886 is now closed

• Black, naturally polled, moderate size

• Excellent marbling, early compositional maturity

• Excellent maternal breed, easy fleshing, good milk

production

• Early maturing sexually

How does melanogenesis connect to selection for coat color?

Melanogenesis = the process of making melanin (pigment), which determines coat color. Genetic variation in melanogenesis genes changes the amount, type, or distribution of pigment, allowing breeders to select animals for desired coat colors.--Genes control melanin → melanin controls coat color → selection favors desired gene combinations."

What is the hereford?

2nd Largest Annual Registration in US

• Originated in Herefordshire, England

• Major US breed from 1920s to 1980s

• Red with white face to behind the ears

• White on the throat, underline, legs, switch

• Moderate size, adaptable, good disposition

• Low to moderate milk, relatively early maturing

• Poorest marbling of the British breeds

• Polled Hereford breed is naturally hornless

• Closed registry

What is the red angus?

Registry started in 1954

• Red, naturally polled, moderate size

• Excellent marbling, early compositional

maturity

• Excellent maternal breed, easy fleshing, good

milk production

• Early maturing sexually

• Red Angus Association allows some grading

up

What is the shorthorn?

Originated in England

• First breed to have a registry

• Three major colors - red, white, roan

• Moderate size, good disposition

• Excellent milk production

• Most numerous in the US until 1920s

• Not significant today

• Has appendix registry which allows outside

genetics to be introduced

What is the south devon?

Originated in England

• First breed to have a registry

• Three major colors - red, white, roan

• Moderate size, good disposition

• Excellent milk production

• Most numerous in the US until 1920s

• Not significant today

• Has appendix registry which allows outside

genetics to be introduced

What is the difference of continental beef cattle to british beef cattle?

• Larger framed and faster-growing than British breeds

• Later maturing and produce less milk than British breeds

• Produce leaner and more muscular carcasses with less marbling

• Used as terminal sires in a two-breed or three-breed cross

What is the charolais?

Originated in Charolles and Nievre, France

• White cattle in the region since 878 A.D.

• Imported to Mexico by Pugibet after WWI

• King Ranch purchased 2 bulls in 1936

• Purebred Charolais 31/32 blood

• White, off-white to cream coloration

• Extremely fast growing, muscular breed

• Large framed with heavy birth weights

• Lean, muscular carcasses

• Progressive ataxia

What is the simmental?

Fifth in annual registrations

• Straw colored through light red to dark red

• US Simmental red or black

• Unpredictable white spotting

• Gentle disposition

• Large framed, large mature size

• Heaviest milking continental breed

• Fast growing in the feedlot

What is the gelbvieh?

German "yellow" cattle

• Breed started in 1850 in Franconian districts of Bavaria

• Stringent selection to repopulate herds post WWII

• AGA started in 1971 and has 45,000 active registered

cows

• Any color, horned or polled, heavy milker

• Fullblood registration 100% Gelbvieh

• Purebred registration 81.6% to 99.9% Gelbvieh

• Balancer cattle are registered hybrid seedstock with 25%

to 75% Gelbvieh and the balance Angus or Red Angus

• Southern balancer are at least 25% Gelbvieh and 6.25%

to 50% tropically adapted breed

What is the Braunvieh?

German for "brown cattle"

• Breeders' society formed in 1897

• Second most populous breed in Switzerland

• Primarily used for dairy in Europe

• 130 animals imported from 1869 to 1880

became nucleus of American Brown Swiss

• Flourished as a beef breed in Mexico

WHat is the chianina?

One of the Oldest Breeds

• Originated in Italy and have different size and

type in different regions

• Largest type was US foundation stock in 1971

• Extremely large framed, late maturing, fast

growing breed

• Lean, muscular carcasses, suspect marbling

• Fullblood, purebreds, and composites

• Fullbloods from white to steel gray in color

• Short horns

• Skin color must be back for fullblood and

Chiangus animals

What is the limousin?

Third in annual registrations

• Originally golden red

• No color requirements in US registry

• Moderate sized continental breed

• Below average maternally, lacking in milk

• Extremely lean, muscular carcasses

• Fastest growing breed in the US

What is the salers?

Native to the Auvergne region of France

• Considered one of the oldest European breeds

• First imports into US in 1975

• DNA screening for beta-mannosidosis since 1995

• Excellent maternal breed

• Good carcass yield and carcass quality

• 28,000+ registrations per year

• Fullblood, purebred, and percentage Salers

• Optimizers have at least 6.25% but less than 75%

Salers blood

What is the Tarentaise?

Originated in the Tarentaise Valley in

the French Alps

• Breed named in 1859 and herdbook founded

in 1888

• First Tarentaise bull imported into North

America in 1972

• Developed in geographic isolation

• Adaptable to harsh environments

• Dual purpose breed

• Moderate size with good muscling

• Fullblood Tarentaise are horned

What are characteristics of American breed beef cattle?

• Bos indicus influence

• Composite design with stabilized composition

• Purpose-bred for southern US environments

• Enhanced heat tolerance

• Improved maternal ability

• Hybrid vigor (heterosis)

• Docility and manageability

• Beef quality and growth performance

What is the brahman?

Developed from 3 Indian breeds

• First American breed

• Originate from Guzerat, Gir, and Nellore

• First importation in 1849

• Red and grey strains with black pigmentation

• Horned

• Large pendulous ears

• Highly developed sweat glands

• Noted for heat tolerance, disease and insect

resistance, and crossing ability

• Poor marbling and slow sexual maturity

What is the beefmaster?

Developed by Lasater Ranch, TX

• From systematic crossing of Hereford,

Shorthorn, and Brahman cattle

• Recognized by USDA as a new breed in 1954

• No color standards

• The Six Essentials - Weight, Conformation,

Milking Ability, Fertility, Hardiness,

Disposition

• Largest number of registrations (~40,000)

What is the brangus?

Developed to combine superior traits

• Crosses began at USDA in Jeanerette, LA in 1932

• 3/8 Brahman, 5/8 Angus

• Moderate size

• Solid black, no brindling, and polled or scurred

• Excellent mothering ability

• Early sexual maturity

• Heat tolerance and foraging ability

• Intermediate in carcass merit

• Red Brangus, Ultrablack, Ultrared, Optimizer

What is the santa gertrudis?

Developed by Kleberg on King Ranch

• 5/8 Shorthorn, 3/8 Brahman composite

• Trace back to a single sire, Monkey

• Short, slick hair

• Deep cherry red color, no black pigment

• Noted for maternal ability of females

• Overall hardiness

• Santa Cruz (50% Santa Gertrudis, 25%

Gelbvieh, 25% Red Angus)

What is meiosis?

cell division that makes gametes (sperm & eggs).

1 diploid cell → 4 haploid cells

Cuts chromosome number in half

Creates genetic variation

Has 2 divisions: Meiosis I & Meiosis II

What are the stages of meiosis 1?

PMAT

Prophase I → homologous chromosomes pair up & crossing over

Metaphase I → homologous pairs line up in the middle

Anaphase I → homologous chromosomes separate

Telophase I → 2 haploid cells form

What are the stages for meiosis 2?

PMAT

Prophase II → chromosomes condense

Metaphase II → chromosomes line up in the middle

Anaphase II → sister chromatids separate

Telophase II → 4 haploid cells form

What are the stages of prophases in meiosis 1?

Leptotene → chromosomes condense

Zygotene → homologous chromosomes pair up (synapsis)

Pachytene → crossing over occurs

Diplotene → homologs begin separating; chiasmata become visible

Diakinesis → chromosomes fully condense; nuclear envelope breaks down

Lazy Zebras Prefer Doing Dishes

What is the ideal dairy type?

• Stature

• Angularity

• Level rump

• Long and lean neck

• Milk veins

• Strong feet and legs

What is the holstein?

Developed in North Holland & Friesland

• First imported to Boston in 1852

• Dominant breed of dairy cattle worldwide

• Bred and strictly culled for efficient

production on grass

• Large frame with unparalleled milking ability

for fluid milk production

• Black and white

• Red and white Holstein recognized as a

separate breed

What is the brown swiss?

Declared a US breed in 1906

• Large framed breed known for its docility

• Coat ranges from light brown with gray to

very dark brown.

• Light muzzle with light dorsal stripe

What is the ayrshire?

First US imports in 1822

• Only native Scottish dairy breed

• Several breeds, including Teeswater stock, Dutch and

Channel island imports were crossed to form

foundation animals

• Dark red and white cattle but no registry restrictions

on color patterns

• Horns are a foot long and curve outwards, but calves

typically dehorned

• Excellent udder conformation, minimal foot and leg

problems

• Moderate buffer fat

• Average 305 day lactation is 14,534 lbs

• Efficient on pasture and hardy in cold weather

What is the Guernsey?

High butterfat, high protein milk

• Developed from Alderney cattle brought to Guernsey

in 960 A.D.

• Coat color varies from yellow to reddish-brown with

white patches

• Introduced into US in 1840 and American Guernsey

Cattle club formed in 1847

• Aggressive young sire selection program for continual

breed improvement

• Consume 20-30% less food per pound of milk than

larger dairy breeds

• Adaptable to warmer climates

What is the jersey?

Excellent breed for cheese making

• Small, feminine cow

• Adaptable to many climates, more heat tolerant

• Excellent grazers

• Very fertile and early maturing sexually

• Light tan to dark fawn with darker shading on

head and legs

• Highest percentage butter fat and significantly

more solids-not-fat than other breeds

What is the difference between qualitative and quantitative traits?

Qualitative = categories → distinct traits, usually 1/few genes Ex: black vs. red coat

Quantitative = quantity → measured/continuous, many genes Ex: weight, height, milk production

What assumptions are made when estimating the number of loci for a quantitative trait?

Alleles are additive

All loci contribute equally

Loci are unlinked

Original parents are homozygous for alternative alleles

How do you predict the number of loci from the number of phenotypes?

Number of phenotypes = 2N + 1

N = number of genes/loci contributing to the phenotype

Solve for N to estimate the effective number of loci

What is the probability of getting an extreme phenotype in an F₂ population?

Probability = (1/4)ᴺ

N = number of genes/loci

Applies to either extreme phenotype

How do you calculate the probability of specific outcomes from multiple loci?

For independent loci, multiply the probabilities together