Swine Production History, Breeds, and Genetics: Key Concepts

What is the scientific name of the domestic pig?

Sus scrofa domesticus

Where were pigs domesticated?

Asia and Europe

Who is called the Father of the American Pork Industry?

Hernando de Soto

When did Columbus bring pigs to Cuba?

1493

How many pigs did Columbus bring to Cuba?

8

When did Hernando de Soto bring pigs to Florida?

1539

How many pigs did Hernando de Soto bring?

13

How large did de Soto's herd become in about three years?

More than 700 pigs

Which city was nicknamed Porkopolis?

Cincinnati, Ohio

What are the four major historical phases of U.S. swine production?

Colonial Days; Revolutionary War to Civil War; Civil War to late 1900s; modern era

Which country ranked first in the lecture's historical pork production table?

China

Which country ranked second?

United States

Which state is a leading U.S. pork producer?

Iowa

What is industry consolidation?

Fewer, larger farms producing more pigs

What is vertical integration?

One company coordinates or controls multiple production stages

What are the seven basic swine production stages?

Breeding, gestation, farrowing, lactation, nursery, growing, finishing

What is a one-site production system?

Most or all stages occur at one farm

What is a three-site production system?

Separate breeding/farrowing, nursery, and growing/finishing sites

What is a pure breed?

Animals selected for uniform heritable characteristics

What are the eight common U.S. swine breeds?

Yorkshire, Landrace, Hampshire, Duroc, Berkshire, Poland China, Spot, Chester White

Which breed is called the mother breed?

Yorkshire

What does a Yorkshire look like?

White body, erect ears, large frame

What are Yorkshire pigs known for?

Large litters, excellent milk production and mothering

What does a Landrace look like?

White, long-bodied, with large drooping ears

What are Landrace pigs known for?

Maternal ability and milk production

Which breed has a white belt around its shoulders?

Hampshire

What are Hampshire pigs known for?

Lean muscle development and terminal-sire performance

What does a Duroc look like?

Solid red with drooping ears

What are Duroc pigs known for?

Growth rate, feed efficiency, and meat quality

What does a Berkshire look like?

Black with six white points and erect ears

What are Berkshire pigs known for?

Excellent marbling and premium pork quality

What distinguishes Poland China from Berkshire?

Poland China has drooping ears; Berkshire has erect ears

What does a Spot pig look like?

Black-and-white spots with drooping ears

What does a Chester White look like?

Solid white with drooping ears

What are maternal breeds selected for?

Litter size, milk production, and mothering ability

What are terminal sire breeds selected for?

Growth, muscularity, carcass quality, and feed efficiency

What is a genetic line?

A population selectively bred for specific traits

What does PIC stand for?

Pig Improvement Company

What is a gene?

A DNA sequence associated with a functional product or trait

What is an allele?

An alternative version of a gene

What is a genotype?

An individual's genetic makeup

What is a phenotype?

An observable or measurable characteristic

What does homozygous mean?

Two identical alleles, such as AA or aa

What does heterozygous mean?

Two different alleles, such as Aa

How many chromosomes do domestic pigs have?

38 chromosomes or 19 pairs

What is the law of dominance?

A dominant allele can mask a recessive allele

What is the law of segregation?

Each gamete receives one allele from each gene pair

What is independent assortment?

Unlinked genes assort independently during gamete formation

What is a qualitative trait?

A trait classified into distinct categories, such as coat color

What is a quantitative trait?

A numerically measured trait, such as daily weight gain

What is additive gene action?

Allele effects contribute to overall genetic value

What is non-additive gene action?

Gene effects involving dominance or interactions

What is heritability?

The proportion of trait variation attributable to genetic differences

What is the narrow-sense heritability formula?

h² = additive genetic variance / phenotypic variance

What is heterosis?

Hybrid vigor; crossbred performance relative to the parental average

What is the heterosis percentage formula?

[(Crossbred mean − Parent mean) / Parent mean] × 100

What are the three types of heterosis?

Paternal, maternal, and individual

What is crossbreeding?

Mating animals from different breeds or lines

What is inbreeding?

Mating genetically related individuals

What is linebreeding?

Inbreeding to maintain relationships to selected ancestors

What does BLUP stand for?

Best Linear Unbiased Prediction

What does MAS stand for?

Marker-Assisted Selection

What is cloning?

Producing an animal with essentially the donor's nuclear genetic information

What is xenotransplantation?

Transplantation of cells, tissues, or organs between species

What is a mature male pig called?

Boar

What is a female pig that has not farrowed called?

Gilt

What is a female pig that has farrowed called?

Sow

What is the main function of the testes?

Produce sperm and testosterone

Where are sperm produced?

Seminiferous tubules

What is the function of the epididymis?

Sperm maturation, transport, and storage

What are the three regions of the epididymis?

Caput, corpus, and cauda

What does the vas deferens do?

Transports sperm toward the urethra

What are the three major accessory sex glands in boars?

Seminal vesicles, prostate, and bulbourethral glands

What do seminal vesicles contribute to semen?

Fluid, buffers, and energy substrates

What is the function of the prostate gland?

Contributes fluid and salts to seminal plasma

What do Cowper's glands produce?

Gel-like secretions in the ejaculate

What type of penis does a boar have?

Fibroelastic, with a sigmoid flexure and corkscrew-shaped glans

What does FSH do in males?

Supports Sertoli cells and sperm production

What does LH stimulate in males?

Testosterone production

Where does fertilization normally occur?

Oviduct

What is the function of the ovaries?

Produce ova, estrogen, and progesterone

What is the average sow estrous cycle length?

21 ± 3 days

At what age do gilts generally reach puberty?

Approximately 6-7 months

What are the four estrous cycle stages?

Proestrus, estrus, metestrus, diestrus

What happens during estrus?

The female becomes sexually receptive and displays standing heat

What is the most important practical sign of standing heat?

A rigid standing response to back pressure

What are common signs of estrus?

Swollen vulva, activity, vocalization, mounting, mucus changes

What is natural mating?

Breeding through physical mating between a boar and female

What is artificial insemination?

Depositing collected semen into the female reproductive tract

What is the average gestation length of a sow?

114 days

What is the memory trick for swine gestation?

3 months, 3 weeks, and 3 days

When do embryos enter the uterus?

Approximately day 3

When does embryo attachment begin?

Approximately days 11-12