Poultry, Monday, July 6th (Sean)

Structure of the Poultry Industry

(There is more known about the nutritional requirements of chickens than any other species, including humans.)

Hormone Myth: Birds are big because of hormones.
There are 2 types of Hormones
Steroid- anabolic; testosterone & estrogen
Polypeptide- human insulin (must be injected because if taken orally it will be digested), growth hormone

Eight Reasons Why We Don't Use Hormones
1. Their use is illegal. The FDA does not allow hormones in any type of poultry.
2. No firm sells hormones for poultry. There is no market, so there is no producer.
3. Their cost is prohibitive. It would be very expensive to develop and market an illegal drug.
4. Administration is difficult. If given orally, steroids would be digested. Would need to be injected repeatedly. Costly labor-wise. With 9 billion broilers being produced every year, this would be impossible.
5. They impact performance "negatively." Even without steroids, the bird can "outgrow its legs & feathering," "living on the edge as is." Sometimes feed must be restricted or the feed's nutrient density has to be adjusted.
6. They do not act like "steroids." Steroid use requires exercise to gain muscle mass. We do not want these chickens to use energy. We want them to sit, stand, eat, and rest; that is all. Any energy use beyond that is a waste of feed. No exercise = No benefit from anabolic steroids. (Breast muscles haven't been used for flying for thousands of years)
7. They're not 100% effective. We want a large breast. Steroid use will not target the breast only. Plus adding any hormones to the chicken interrupts the growth cascade. Growth has to happen in a specific order, at a specific rate. Any interruption to the growth cascade can ruin the chicken.
8. They're simply not needed. We have excellent genetics. These birds are selected for their high feed intake which spurs the rapid growth. Chickens have the best feed conversion ratio of all land animals (1.8-1.9 lb of feed per lb of body weight).

Most commonly asked question... "Why does the Poultry Industry use hormones?"
...not "Does the Poultry Industry use hormones?"
Chickens are NEVER fed hormones. The only hormones you will find in the chicken are the ones that occur naturally.

EGG ----------------> BROILER
takes 7 weeks

a finished broiler will be 100x it's hatch weight
at 4 wks old, problems may start occurring, especially if hot

Genetically speaking, domestic chickens originated from Red Jungle Fowl (be able to recognize).

Documented use in India 3200 BC, China 1400 BC. They were brought to Europe for cockfighting. Then to the Caribbean (& south Florida, Mexico, etc) for religious rituals like voodoo.

The "Real" Beginning
All Birds came from reptiles. Feathers are modified scales.

Archaeoteryx (know how to spell!)
means "ancient wing"

Nine have been discovered so far. In 1861 the first one was discovered in Bavaria, Germany. They are about 2 feet tall and about 1lb. They might not have been able to fly but they could have soared from trees and ledges.

Commercial Poultry
Chick hatches using an egg tooth.
Egg tooth is made out of keratin.
Your heel is soft keratin; nails are hard keratin.
If you add more sulfur to your diet you keratin will get stronger. (why burning hair, nails, skin, smells like sulfur)

cysteine- disulfide bridge -cysteine

Insulin also has a disulfide bridge

== Copied from internet but sums up what he said ==
keratin: Fibrous structural protein of hair, nails, hooves, wool, feathers, and skin. A quarter of the amino acids in keratin are cystine, whose ability to form strong bridging (disulfide) bonds with other cystine units accounts for keratin's great stability.========


Hen Reproduction



<--- ova is just a yolk


<--- sperm gland at base of infundibulum


<--- Magnum- Albumen white is added


<--- Isthmus- membrane & chalazae are added



<--- Uterus- shell gland (starts to lay shell, takes 20 hours)

<--- sperm gland at entrance to vagina

<--- cloaca means sewer

• Chalazae (2) are tightly bound protein spirals that are at each end of the yolk to keep the yolk in the center. A large chalazae indicates a fresh egg.

• Sperm glands ("nests") are crevices where the sperm can hide out for up to 10 days if there is an egg blocking the way to the infundibulum.

• 3 tracts meet at the end of the repro system; digestive, reproduction, & urinary (the white stuff in bird poo) After the egg is layed, it takes 21 days to hatch.