1. Diseases in Animal Agriculture: Introduction
Today, raising poultry of all kinds is growing in popularity. You need caring,
perseverance, and a good deal of knowledge to breed and raise birds, but it is a
very rewarding activity that gives endless personal satisfaction and pride.
By the end of this lesson, you will be able to:
Define the causative agents of diseases
Define how a virus infects the host and spreads from farm to farm
Understand the interconnectivity and global nature of animal agriculture
Define the global size and interconnectivity of the animal science market
Discuss one example of how a disease outbreak in animal agriculture impacts the economy
Understand the difference between an animal carrying a disease agent and exhibiting the clinical signs
Audio Script: To raise poultry you need caring, perseverance and knowledge of breeding and raising birds. Just as important, is the need to know about diseases that can harm or kill your poultry, and the things that cause these diseases.

2. Causative agents of diseases
Is a deviation from normal health
Is an abnormal condition that is the result of infection, basic weakness or environmental stress that prevents normal functioning
Avian diseases range from reduced production and loss of energy to death.
Infectious diseases are caused by microscopic pathogens, including bacteria,
viruses, protozoa and fungi.
Audio Script: In common terms, disease is an abnormal condition that is the result of infection, basic weakness or environmental stress that prevents normal functioning. The effects can range from reduced production and loss of energy to death. Disease can be infectious or non-infectious.
In poultry, there are four main classes of disease-causing agents: bacteria, viruses, fungi and parasites. 

3. In poultry there are four main classes of pathogens:
Viruses
Microscopic viruses cause diseases such as:
Avian Influenza
Exotic Newcastle Disease
Bacteria
Microscopic bacteria cause diseases such as:
Mycoplasmosis
Fowl Cholera
Fungi
Microscopic fungi cause diseases such as:
Aspergillosis
Mycotoxicosis
Parasites
Parasites can cause diseases such as:
Coccidiosis
Histomoniasis (blackhead)

4. How Poultry Disease Spreads
Audio Script: Be careful! If you are visiting a farm, you can spread disease through your clothes, boots and hands. You can also spread disease through your car, truck, tractor, or other farm vehicles.
Poultry equipment can also spread disease if it is not cleaned regularly. Equipment such as filler flats, hauling crates or coops, feeders and waterers must be thoroughly cleaned regularly. Finally, diseases may spread from bird to bird, and through manure, litter and debris, feathers and improperly disposed carcasses.

5. How a Virus Operates and Spreads in the Environment
1. Directly
As a result of contact between a sick bird and a healthy bird or by carrier birds to healthy birds
Infected manure
Aerosol transmission - through respiratory droplets
2.Indirectly
Virus-bearing material can be picked up on shoes, clothing, hands and vehicles which is then carried to healthy birds
3.Other Vectors
Wild animals, rodents and insects
Audio Narration: There are three forms of transmission of a virus:
DIRECTLY: Through contact.
INDIRECTLY: Through virus-bearing material.
OTHER VECTORS: Such as wild animals.

6. Disease Recognition
Sick birds are inactive and dull and tend to isolate themselves from other healthy birds in the flock.
Audio Script: Recognizing disease in your birds is sometimes obvious. But, by the time the disease is obvious, it may be too late. So it is very important for you to know your birds' "normal" or healthy behavior by observing them closely.
True, it's difficult to recognize a sick bird, especially in the early phases of illness. This is because birds are experts at hiding their signs of disease. This is a defense mechanism to insure their survival in the world. Therefore, they often do not appear ill until their disease state is advanced. A trained eye or an astute ear can recognize the subtle signs of early disease.

7. Disease Recognition
Sick birds are inactive and dull and tend to isolate themselves from other healthy birds in the flock.

8. Disease Recognition
Sick birds are inactive and dull and tend to isolate themselves from other healthy birds in the flock.

9. Disease Recognition
Sick birds are inactive and dull and tend to isolate themselves from other healthy birds in the flock.

10. Disease Recognition
Sick birds are inactive and dull and tend to isolate themselves from other healthy birds in the flock.

11. Disease Recognition
Sick birds are inactive and dull and tend to isolate themselves from other healthy birds in the flock.

12. Disease Recognition
Sick birds are inactive and dull and tend to isolate themselves from other healthy birds in the flock.

13. Global Nature of Diseases in Animal Agriculture
Today's global marketplace means greater access than ever before to agricultural commodities from around the world. This requires greater vigilance to ensure that imports and exports comply with international trade standards. With world trade, business travel, and global tourism, it becomes easier to transport unwanted pests and diseases.
For example:
A visitor to a farm in Southeast Asia that has high-pathogenicity AI or END can be on his or someone else's farm in the United States within a day or two, and possibly carrying the virus on himself or on his clothes or shoes
Disease can come in through mislabeled illegally imported poultry products, as it did in one instance with frozen ducks. These ducks could well have been carriers of disease
Audio Script: Disease in animal agriculture can spread easily through illegal export and import of animals. For example, an outbreak in one country can easily affect the birds of another country. That is why the USDA has strict regulations for importing animals and animal products. Birds illegally transported from countries suffering from an outbreak of a disease can spread it across the world within 48 hours.

14. Federal and State Responses to a Disease Outbreak
Federal and state agencies have prevention and response procedures for disease outbreak.
Prevention
The primary responsibility for preventing an outbreak lies with the USDA/APHIS and the states often working in conjunction with other federal agencies, tribal nations and industry. APHIS uses trade restrictions to help keep diseases from entering the country. It updates the Department of Homeland Security on agricultural threats so they can be vigilant in checking for prohibited products.
APHIS trains veterinarians across the country as foreign animal disease diagnosticians. A key to early response is quickly investigating a possible foreign animal disease. (That is why, for example, you are asked to report sick or dying chickens.)
Audio Script: Preventing disease outbreaks from happening lies with the USDA and the states, often working in conjunction with other federal agencies, tribal nations and industry.

15. Response
If there is a foreign animal disease outbreak, APHIS would head the emergency response. The response would take place at the local level, and if the scope of the outbreak is beyond APHIS and the affected States' immediate resource capabilities, additional resources can be obtained. APHIS can also turn to its roster of accredited veterinarians and animal health technicians for additional help.
The National Animal Identification System (NAIS) is intended to identify animals and track them. This voluntary system will enhance U.S. efforts to respond to outbreaks of animal diseases more quickly and effectively. The goal is to have a system that can identify all premises and animals that have had direct contact with a foreign animal or domestic disease of concern within 48 hours.
NAIS website
To learn more about the National Animal Identification System (NAIS), click the following link

16. Trade Involving Animals and Animal Products
Through its' National Center for Import/Export (NCIE), the Animal and Plant
Health Inspection Service (APHIS), part of the U.S. Department of Agriculture
(USDA), works to maintain clear rules for trade involving animals, animal
products, and plants that arrive in and leave the U.S.
APHIS works closely with the Department of Homeland Security to prevent international passengers from bringing in foreign pests and diseases. More than 300 APHIS veterinarians are stationed throughout the United States to investigate suspected foreign animal diseases
These efforts, along with emergency preparedness and surveillance activities, also enable the United States to capitalize on world export markets
To make sure that international animal health standards represent the interests and concerns of the United States, APHIS is active in the international standard-setting body, the World Organization For Animal Health or OIE. These international standards shape the future of animal trade world wide
Audio Script: Over that past two or so decades, nations have embraced trade agreements that have changed the way the world does business. Countries have opened their doors to the prospects of new trade opportunities and expanded partnerships with other nations, particularly in the area of agriculture.

17. The Role of APHIS Regarding the Safety of Animal Exports
APHIS is at the forefront of facilitating the export of live animals and genetic material. This is due to the agency's ability to confidently certify the U.S. animal health status to foreign trading partners.
It ensures that livestock headed to other countries meets the standards required by those nations to maintain the world's confidence in the integrity of the health of U.S. animals and animal products
Physical examinations and blood tests, usually done by USDA-accredited veterinarians, cover both U.S. export requirements and the frequently complex requirements the receiving nation
An APHIS veterinarian endorses export health certificates only after all tests and other requirements have been met
A final examination is conducted by an APHIS veterinarian at the port of export before the livestock or poultry leave the country
Audio Script: APHIS is at the forefront of facilitating the export of live animals and germplasm. This is due to the agency's ability to confidently certify the U.S.' animal health status to foreign trading partners.

18. Working With the World Organization For Animal Health
The World Organization for Animal Health (OIE) in Paris, and APHIS play an important
role in safeguarding the United States from foreign animal diseases. As a member of
OIE, USDA/APHIS ensures that international health standards are fair and scientifically
justified.
Audio Script: The OIE in Paris, commonly known as the World Organization for Animal Health, monitors animal diseases worldwide.
Veterinary Services within the USDA's Animal and Plant Health Inspection Service play an integral role in the mission of protecting American animal agriculture.

19. USDA Veterinary Services
USDA/APHIS through its Veterinary Services (VS) program is charged with several critical tasks.
Most important is VS' responsibility for protecting and improving the health, quality, and
marketability of our nation's animals, animal products and veterinary biologics. VS also:
Facilitates international trade
Monitors the health of animals legally coming into the country
Monitors, on a daily basis, reports from OIE on the status of international diseases in
order to protect the United States from importing animals and products from countries
with disease outbreaks
VS is at the forefront of APHIS' effort to safeguard the health of our nation's agricultural
resources. Its many animal health experts work closely with other federal agencies, states,
foreign governments, industry and professional groups, and others to enhance international trade
and cooperation while preventing the introduction of dangerous and costly pests and diseases.
USDA Veterinary Services website :

20. OIE
The OIE comprises 167 member countries. It:
Ensures international animal health standards
Ensures transparency in global animal disease situations because member nations agree to report animal diseases they detect, and then the OIE provides this information to all members
Safeguards world trade by publishing health standards for international trade in animals and animal products
When a country has an outbreak of a highly transmissible disease, other countries often stop trade in that region or even with the entire country. This is one reason why the federal and state governments work very hard to keep the U.S. free of foreign animal diseases.
World Organization For Animal Health website :

21. Summary
In this lesson, you've learned about:
The causative agents of diseases
How a virus operates and spreads in the environment
The global nature of diseases in animal agriculture
The global size and interconnectivity of the animal science market
How a disease outbreak in animal agriculture impacted the economy
Understand the difference between an animal carrying a disease agent and
exhibiting the clinical signs
Audio Script: You've come to the end of this lesson. Here, you learned about the agents of avian disease, how a virus operates and spreads, and the impact of avian disease on the global economy.

22. Correct Answer: Are displayed on the next page.
Now Try This
Recalling the symptoms of diseases, match each symptom listed on the
left with the appropriate description on the right.
Signs
Description
Respiratory
Fertility of eggs
Gastrointestinal
Discharge from mouth
Neurological
Eyes closed most of the time
Change in physical appearance
Weight loss
Change in character or behaviors
Partial or complete paralysis
Reproductive
Persistent ruffled feathers
Correct Answer: Are displayed on the next page.

23. Correct Answer:
Signs
Description
Respiratory
Discharge from mouth
Gastrointestinal
Weight loss
Neurological
Partial or complete paralysis
Change in physical appearance
Persistent ruffled feathers
Change in character or behaviors
Eyes closed most of the time
Reproductive
Fertility of eggs