POSC 201 exam 2

What is an example of vertical integration?

- One company will have its own feed mill, hatchery, grow out farms, processing plant

- the company provides feed, new chicks, flock service, and feed

What is a broiler house/

A 16' wide barn headed by a coal stove

What happened from 1935 to 1950?

Individual independent poultry producers were responsible for all facets of the industry and thus had a limited supply

What happened from 1950 to 1955?

Horizontal integration (expensive due to middleman)

What is happening between 1955 to present?

- vertical integration

- specialized lines for meat production, straight run

- specialized lines for egg production, hens only

Vertical integration

One company focus on one segment of the industry (egg, broiler, or turkey) and owns all aspects of production

Egyptian and Chinese records show that fowl were laying eggs for man in ________ BC

1400

How many eggs can hens produce per year?

Over 300

How many eggs did hens lay on average in 1947?

150

Most laying hens are ____________ (white egg producers) or sex-linked hybrids that remain New Hampshire Reds and Barred Plymouth Rocks (brown egg producers)

Hybrid White Leghorns

What is "a chicken in every pot"?

Not a commercialized industry pre-ww2

- 1928 presidential campaign slogan (Herbert Hoover)

What was a chicken in every pot typically raised for?

Egg production in backyards

- roosters don't lay eggs, primary selection for dinner

What happened in 1923?

The differentation of chickens began

- selecting for chickens that were either good laying hens or for meat-type chickens

Where was the founding of the broiler industry in 1923?

Delmarva peninsula

What are modern broiler barns?

60' wide and 600' long

How did the poultry industry start?

With 500 birds

- sold 387, 2 pound chickens for $0.67 per pound ($11.98/lb in 2023)

New York dress

Killed, Bled, and picked (feathers removed) for marketing but with head, feet, and viscera intact

What is the "chicken of tomorrow"?

National contest sponsored by the USDA and industry companies from 1945-1948

What was the goal for "chicken of tomorrow"?

Create a "sumptuous" breed of chicken with the "breast of a turkey"

Who was the winner of the "chicken of tomorrow" contest?

Charles Vantress, who went on the found Cobb-Vantress Inc.

- he used a New Hampshire x Cornish Hybrid

1890 egg production

100 eggs/hen/year

2000 egg production

257-280 eggs/hen/year

What parts are not owned by vertical integrator?

Genetic breeder, supermarkets, contract grower

Genetic breeder

improvement of genetic stock is expensive and time consuming

Supermarkets

make their own prices

Contract growers

Owns the land and houses but are under contract with the integrator

What are the 2 main management types for egg production?

- conventional

- cage free

Brown vs white eggs

-no nutritional difference

-brown eggs are more expensive to produce

Why are brown eggs more expensive to produce?

- Brown egg-laying hens are larger than their white counterparts, and therefore eat a little more, and require larger housing arrangements

- also produce fewer eggs

How are breeders raised?

In a slatted floor house with automatic watering, feeding, and egg collection systems

What are produced depending on the desired egg market?

Both white-shelled and brown-shelled eggs lines

What are the rearing stages?

Brood and grow, day 1 to approximately 16 to 18 weeks

If there was no molt in the rearing stage how loving would it take?

95-100 weeks

Flat deck caged system

- more density per house, multi level cages

- reduced medication costs for soil borne pathogens, i.e., coccidiosis, black head, etc

- eliminate environmental shock of moving from floor to wire

- easy access to birds vaccinate, weigh, etc

How is the interior grade determined?

By air cell, indication of freshness

Air cell size

Increases with time, rate depending on storage environment

What does the presence of blood or flesh do to the interior grade?

Renders egg inedible or loss

What causes a blood spot?

During laying stuff gets in the egg

What is included in the interior appearance?

Albumen, yolk, air cell

Interior appearance - albumen

- clear and firm

- reasonably firm

- weak and watery

Interior appearance - yolk

- distinctness and visibility

- size and shape

- defects

Interior appearance - air cell

Overall size

What is included in the exterior appearance?

Shape, shell soundness, shell cleanliness

Exterior appearance - shape

- oval shaped

- ridges or rough areas

Exterior appearance - shell soundness

- thin spots

- leaks

Exterior appearance - shell cleanliness

- cage marks

- stains

- dirty

Egg breaking machines

Widely used in egg powder processing, bakery products, ice cream production, and other egg processing procedures related egg liquid separation

What are the outer egg parts?

Eggshell and shell membranes

Eggshell

made almost entirely of calcium carbonate (CaCO3) crystals. It is a semipermeable membrane, which means that air and moisture can pass through its pores.

Shell membrane

Lying between the eggshell and egg white, two transparent protein membranes provide efficient defense against bacterial invasion

What are parts of the egg structure?

Air cell and chalazae

Air cell

air space forms when the contents of the egg cool and contract after the egg is laid. The air cell usually rests between the outer and inner membranes at the egg's larger end and grows larger as an egg ages

Chalazae

opaque ropes of egg white, the chalazae hold the yolk in the center of the egg

What is the function of the chalazae?

Keeps embryo centered during incubation

What are parts if the interior of the egg?

Yolk and albumen

Yolk

contains less water and more protein than the white, some fat, and most of the vitamins and minerals of the egg.

What is the function of the yolk?

Provides energy and micronutrients for the embryo

Albumen

layers of thick and thin albumen contain approximately 40 different proteins, the main components of the egg white in addition to water.

What is the function of the albumen?

Provides hydration for developing embryo

Blastodisc (germinal disc)

Where embryonic development begins in a fertile egg. Female chromosomes

Cuticle

Thin outermost coating of the shell called the bloom or cuticle

- first guard against microbial invasion and gas exchange, hydration loss

- easily dissolved with washing or moisture

Which ovary and oviduct are fully developed?

Left

What happens to the right ovary and oviduct?

Regress during sexual maturation

What dies the ovary contain?

Developing egg yolks (follicles) and a large number of small white follicles

- born with all eggs that they will ever lay in their lifetime

Oviduct

Site of egg white secretion, shell membrane, and eggshell formation

OIMIUVC

Ovary-> infundibulum-> magnum-> isthmus-> uterus-> vagina-> cloaca

infundibulum

not connected to ovary, site of fertilization, 18 minutes

magnum

majority of albumen is formed here, 2-3 hours

isthmus

site of membrane formation and addition; beginning of the shell formation, 75 minutes

uterus

aka shell gland; deposition of calcium to from shell (w/ pigments) and add cuticle, 18-26 hours

vagina

assist with expulsion of the egg. sperm storage tubules located here at utero-vaginal junction. Evidence for FILO sperm release.

cloaca

site of egg exit

male reproductive system

male fowl have two testes located high in the abdominal cavity, along the back, near the cranial poles of the kidneys

testes

- in roosters

- gonad size variation

testes in roosters

- both testes develop with sexual maturation

- testes continually produce sperm while sexually mature

gonad size variation

- during seasonal breeding, testes can increase in size by over 50% in response to photo-stimulation

- testes regress when not in breeding season

what percent of birds lack a penis?

97%

unique male genitalia

- high concentration + low accuracy

- rudimentary copulatory organ, or male process

which bird do have a penis?

ostriches, emus, ducks, and geese

Caponization

castration (removal of testes) in an adolescent bird while the immature gonads are small and easy to remove

intact males

- fast growth rate

- coarse, stringy, tough meat

- not super flavorful with older age

why caponize?

- reduced growth rate

- meat that is more tender and juicier

- more flavorful meat with older age

what is caponize a specialty product?

- expensive due to mortality rate

- lost art

mating

male courts the female (both verbal and non verbal behavior) and finally mounts her, joining cloacal proctodeal which turn inside out

embryology

the branch of biology and medicine concerned with the study of embryos and their development.

zygote definition

single cell with the correct number of chromosomes

zygote

- chickens, poultry, and fowl are diploid (2 complete sets of chromosomes)

- chickens 2n=78/n=39

- other birds species may have more or less

chromosome numbers: gallus gallus

2n=78

chromosome numbers: struthio camelus

2n=80

chromosome numbers: anus castanea

2n=82

when did the embryonic development of chickens begin?

1900

why study chickens?

- rapid development of vertebrate animal model - limb formation

- cheap, easily accessible and manipulated

1951 - viktor hamburger and howard hamilition (HH)

- most accurate description of staging series for 60 years

- 46 different chronological stages in chick development in 3 phases

- used from 1951- mid 2010's

what are the 3 different developmental phases?

differentiation, growth, and maturation

phase 1 - differentiation

- incubation days 0-6

- HH1-HH28 (stages 1-28)

- when cells differentiation, heart formation and begins beating, and beak becomes visible

phase 2 - growth

- days 7-16

- HH29-HH42 (stages 29-42)

- Organs are approximately 95% of their final size on day 11, so the focus is on organ size and physiological growth

phase 3 - maturation

- days 17-21

- HH43-HH46 (stages 43-46)

- embryo has reached its final size by day 17, growth rate decreases and the embryo is focused on getting ready for the outside world

day 1

appearance of tissue development

day 2

tissue development very visible; appearance of blood vessels and heart

day 3

blood vessels very visible; heart beating