meat and poultry

Meat and Poultry

Definition

Meat•Refers to the muscles of animals used as food. Internal organs of animals used as food is also included in this broad definition.

•The animals commonly raised for meat worldwide are cattle, sheep, pig and poultry which is dominated by chicken.

•Other mammalian species are also used as food in various parts of the world according to culture and availability.

Poultry•The word poultry refers to all domesticated birds raised for their meat. Although chickens are the most popular poultry consumed, other species includes turkeys, ducks, geese, guinea fowls and pigeons.

•Game birds such as pheasant, wild duck, and quail are also consumed, but few of them reach the marketplace. Not readily available in all parts of the country yet, but starting to be seen, are emus and ostriches.

Consumption of Meat•Throughout the history, meat has been considered a high value food. Nutrition studies indeed show that meats are high grade protein sources. The low consumption of meat in many countries in Asia and Africa was then considered to be the reason for malnutrition for these regions. Subsequent studies and further analysis proved that assumption to be a fallacy. Malnutrition is a consequence of poverty, which in turn has interrelated causes, lack of food being foremost.

Philippine Per Capita Consumption of 4 Major Meat Products

Year Pork (kg) Chicken (kg)

Beef (kg) Carabeef (kg)

1995 11.61 5.83 2.02 0.87

1996 12.21 6.51 2.21 0.92

1997 12.54 6.96 2.43 1.03

1998 12.70 6.75 2.32 0.93

1999 13.10 7.03 2.43 1.16

Average 12.43 6.51 2.28 0.98

Source: Department of Agriculture – Agribusiness and Marketing Systems 2003

•Today, the over consumption of meats, is considered to be a major culprit of the so called lifestyle diseases. The current accepted healthy diet means less red meat, use of chicken and fish and more complex carbohydrates from fruits and vegetables. A good balance of food from animal and plant sources ensuring a wide variety of food sources in both categories, and eating in moderation, then as now, is still sound advice.

Lifestyle Diseases•A disease associated with the way a person or group of people lives. Lifestyle diseases include atherosclerosis, heart diseases, and stroke; obesity and type 2 diabetes; and diseases associated with smoking and alcohol and drug abuse. Regular physical activity helps prevent obesity, heart disease, hypertension, diabetes, colon cancer, and premature mortality.

Estimated Per Capita Poultry Meat Consumption in Selected Countries (2002)

Country Consumption (kg)Philippines 6.7

India 0.7Indonesia 3.4

China 9.6Korea 11.3

Thailand 13.0Japan 13.8

Malaysia 32.1Australia 32.4Taiwan 34.0

USA 49.3Hong Kong 57.4

Source: Foreign Agriculture Service, Dept. of Agriculture 2003

Meat Structure

Muscle

Muscle

Muscle Bundles

Muscle Fibers

Myofibrils

Myofilaments

- we consider it as the meat in the animal used as food.

- basic cellular units of both the living muscle and of meat.

- sarcomere is its basic unit.- Two filaments: THICK ACTIN and the THIN MYOSIN (also called the contractile proteins)

- Embedded in sarcoplasmic protein matrix

The smallest unit readily discernable is the bundle of muscle fibers, enclosed in a sheath, the perimysium. Muscle fibers are the basic cellular units of both the living muscle and of meat. These fibers are multinucleated and are rather long relative to their diameter. The connective tissue around each muscle fiber is the endomysium.

Schematic Diagram of Muscle Fiber in relation to Connective Tissues

Connective Tissues

•Meat animal’s body is supported by bones and tendons. Held together by fibrous connective tissues.

•Merged into a large mass, the tendon at the termini of each muscles which is anchored to the skeleton. Veins and arteries as well as larger nerves are inside the perimysium, while capillaries and the smaller nerves are in the endomysium.

•Contains two types of proteins: COLLAGEN and ELASTIN

Collagen•Embedded collagen fibers is where the

strength of the bones came from (also calcium)

•Elongated proteins that form extremely strong but small fibrils which associate together to form collagen fibers which in turn form sheets or cables that can be easily distinguished in meat cuts.

•Collagens are the most abundant protein in the animal body and important in determining the toughness of the meat.

Collagen•Collagen fibers shrink in hot water and

are converted to gelatin. At around 65°C, the helical structure of collagen is disrupted and the chains fall into random arrangement making way for the conversion to gelatin. This change is significant in the tenderization of meat cuts with high connective tissue content.

Elastin•Elastin has true elastic properties compared to collagen which derives its elasticity only when it forms into cable-like tendons.

•Elastic properties are necessary in the tissues of the neck, the abdominal/intestinal wall and the arterial system.

Location of Fat•Fat cells are usually located

abdominally, under the skin and within in the endomysium surrounding muscle fibers

Marbling•When fat is associated with the

muscle fiber due to its appearance in the meat as wavy lines and resembles the appearance of marble.

Meat Composition

Meat composition varies with:- Species of animal source- Species variations due to breed, age

and sex, diet and exercise conditions.- Anatomical placement of the meat in

focus.

Meat Protein Fat Ash Water

Beef 17.5 22.0 0.9 60

Veal 18.8 14.0 1.0 66

Pork 11.9 45.0 0.6 42

Lamb 15.7 27.7 0.8 56

Horse 20.0 4.0 1.0 74

Chicken 20.2 12.6 1.0 66

Duck 16.2 30.0 1.0 52.8

Turkey 20.1 20.2 1.0 58.3

Typical Percentage Composition of Some Meats with Medium Amounts of Fat

Color Changes in Meat and Post Mortem

Post Mortem Changes in Meat•The process of converting once living

muscle to meat begins soon after the animal has been bled and the oxygen in the muscles is rapidly exhausted.

•Impartial bleeding is a major defect that leads to early meat spoilage.

Post Mortem Changes in Meat•Pre-rigor stage•Rigor Mortis•Post Rigor Stage•Meat PH•PSE and DFD Meat

Pre-rigor stage•Involving a series of changes in cell

metabolism as well as the protein structure.

•Upon death, the ATP stores are depleted, oxygen is stopped, leading to anaerobic glycolysis and subsequent formation of lactic acid which in turn in cause the pH to fall.

Rigor Mortis•Immediately after the animal is killed, the

muscles are soft and pliable. •As the pH falls, the development of a stiff

and rigid conditions occurs.•Biochemically, it is accompanied by the

formation of actomyosin a linked protein from what was previously two distinct actin and myosin proteins of the muscle fiber.

Rigor Mortis•The onset rigor mortis occurs within the

first 12 hours after slaughter and may last for varying periods within 24 hours.

•For chicken the onset is less than 30 minutes, for turkey less than one hour, the pork from 15 minutes to 3 hours. And for beef 6 to 12 hours (Hulitin, HO, 1976).

•Fishes are known to exhibit shorter rigor mortis periods.

Post Rigor Stage•After the stiffening process, that

characterizes rigor mortis, the muscles gradually tenderize.

•The main factor in the resolution of rigor is loss of biological regulation of proteinases.

Chilling and Cold Shortening•Used to control post rigor changes.

Factors lead to deterioration because of Bacterial and Enzymatic Action:•The condition of slaughter.•The health and condition of the animal

prior to slaughter.•The storage condition of the meat.•The pH or acidity of the meat.

Meat pH•The drop in pH is one of the most mortem

biochemical events in meat.•Normal pH is 7.2 to 7.4 which is reduced to

about pH 5.5 for red meats and about pH 5.9 for poultry.

•The loss of water holding capacity (WHC), in turn leads to low product yield and pork quality.

•WHC is the ability of meat to retain its water during processing, storage, and cooking.

PSE and DFD Meat•PSE: Pale, Soft, Exudative• DFD: Dark, Firm, and Dry•A low meat ph is often associated with

low WHC and pale meat colr.•High Meat pH oftens causes a dark meat

color, both pale and dark colors are unattractive to costumers and have poor cooking quality.

pH and Meat PropertiesRate of pH decrease

Final pH Meat Characteristic

Slow and Gradual 6.0-6.5 .Dark MeatSlow and Gradual 5.7-6.0 Slightly Dark MeatGradual 5.3-5.7 Normal ColorRapid 5.3-5.6 Normal ColorRapid 5.0 Normal Color to

slightly DarkRapid 5.1-5.4 then 5.3-5.6 Dark to Pale.

ExudativePale and exudative

Meat Cuts, Types of Meat and Poultry and Aging

Meat cuts1. Carcasses2. Primal or wholesale cuts3. Fabricated cuts

Primal and wholesale

Lamb

Types of meat and Poultry

(Meat)

Beef- The ancestor of the beef cattle was a type

of wild ox domesticated in ancient Greece and Turkey during the stone age.

- Red meat consumption continues to increase to North American consumers.

- Beef originates from cattle that are classified according to gender and age:

1. Steers- male cattle that are castrated while young.

2. Bulls- these older uncastrated males that provide stag meat usually used for breeding.

3. Heifers and cows- heifers, females that have not borne a calf, are also used for meat. The meat from cows, female cattle that have borne calves.

4. Calves- their meat is inferred to as baby beef.

Veal- Veal comes from the young calves of beef

cattle. These very young animals are fed a milk-based diet or formula that have their movements greatly restricted, resulting in meat with an exceptionally milky flavor, pale color, and tender texture.

Veal chop

Lamb and mutton- Lamb and mutton are the meat of sheep.- Difference between the two is the age of

the animal from which they come.•Lamb comes from sheep less than 14

months old, and mutton from those over 14 months.

•Mutton is also darker and tougher than lamb and has a stronger flavor

Mutton

Pork - Most pork is derived from young swine of

either gender slaughtered at 7 months of age.

- About one-third of all pork is sold fresh, whereas the rest is cured and provided to consumers as ham, sausage, luncheon meats, and bacon.

Types of Meat and Poultry(Poultry)

Chicken (Poulet)• Most popular and widely

eaten poultry in the world• Inexpensive and readily

available• Contains both light and

dark meat• Relatively lean• Available fresh or frozen

in a variety of forms• Extremely versatile

Chicken Classes• Game Hen

▫ 5-6 weeks old• Broiler/fryer

▫ 13 weeks old• Roaster

▫ 3-5 months old• Capon

▫ Under 8 months old• Hen/stewing

▫ Over 10 months old

Game Hen• Young or immature

progeny of Cornish chickens or of a Cornish chicken and a White Rock chicken

• Very flavorful• 2 lb. or less• Spit roast, broil,

grill or oven roast

Broiler/fryer• Young with soft,

smooth textured skin

• Relatively lean• Flexible breastbone• 3 lb. 8 oz. or less• Can use any cooking

method

Capon• Surgically castrated male • Tender meat with soft

smooth skin• Bred for well-flavored meat• Contains a high portion of

light to dark meat• Relatively high in fat• 6-10 lb.• Roast

Cuts of Chicken

Duck (Canard)• Classes

▫ Broiler▫ Roaster▫ Mature

• Contains only dark meat• Large amount of fat• High percentage of

bone and fat to meat• Roast

Goose (Oie)• Classes

▫ Young▫ Mature

• Contains only dark meat

• Very fatty skin• Popular at holidays• Served with acidic

fruit-based sauces to offset fattiness

Guinea (Pintade)• Classes

▫Young▫Mature

• Domesticated descendant of a game bird

• Has both light and dark meat

• Tender enough to sauté

• Contains little fat• Usually is barded

prior to roasting

Pigeon (Pigeon)• Commonly called

squab• Contains only dark

meat• Meat is tender• Contains very little

fat• Suited for broiling,

sautéing or roasting

Turkey (Dinde)• Classes

▫ Fryer/roaster▫ Young▫ Yearling▫ Mature

• Second most popular category of poultry in the U.S.

• Contains both light and dark meat

• Relatively small amount of fat

• Young turkey can be prepared in any manner

74

Ratites•Ostrich•Emu•Rhea

OSTRICH

Aging•Aging is a practice of storing meat

carcasses usually beef at chill temperature just above 0º for 10-14 days at70 percent relative humidity prior to cutting. This practice has been shown to increase beef tenderness.

•Pork and lamb are usually not aged.

Types of aging • Dry Aging

- It is accomplished with careful temperature and humidity and air flow monitoring. Ultra violet is sometimes used to control microbial growth. -Carcasses are hung in refrigeration units at 34°F to 38°F (1°C to 3°C) with low (70 to 75 percent) or high (85 to 90 percent) humidity for 11 ⁄2 to 6 weeks.

• Fast Aging- It involves holding the meat at higher temperatures for shorter time. - Most beef is aged in plastic shrink-wrap. Warmer temperatures of 70°F (21°C) with a high humidity of 85 to 90 percent lower the aging time to 2 days, but additional aging will occur during the 10 or so days it takes the meat to reach the consumer. Ultraviolet lights are used to inhibit microbial growth. Most retail meat is fast aged.

• Vacuum Pack Aging- meat cuts are vacuum packed prior to aging at controlled temperature.- Less weight loss and spoilage occur in meats that are aged by vacuum packing (cryovacing). During this process, meat carcasses are divided into smaller cuts, vacuum packed in moisture- and vapor-proof plastic bags, and then aged under refrigeration.

Tenderizing Meat And Poultry

TendernessIt involves three aspects:

1. the initial penetration of the meat by the teeth upon biting/chewing

2. the ease in which the meat breaks into fragments, and 3. the amount of residue left after chewing. (Weir 1960)

Tenderness of the meat is affected by both Pre-Slaughter and Post Mortem Factors

Pre-Slaughter Factors1. Species of the animals from where the meat is taken.2. The specific breed of the animal3. Age and Sex4. The specific part of the animal from where the meat was

derived.5. Stress on the animal before slaughter

Post Slaughter FactorsPost-Slaughter Factors are: post mortem glycolysis, aging,

tenderizing treatments and storage.

• Post mortem glycolysis-is a series of chemical reactions, which include the

conversion of muscle glycogen to lactic acid: resulting in increased in acidity (lowering of pH).

• Aging- Is a practice of storing meat carcasses usually beef at chill temperature just above 0C for 10-14 days at percent relative humidity prior to cutting.

Dry Aging- original method- carried out in controlled

environment with temperatures of 0 to 20C, 80to 85% relative humidity and air flow of 0.5 to 2.0 m per second for 3 to 4 weeks. Uncovered meat is hung in rails in these controlled rooms.

Wet Aging- aging occurs when the meat cuts

are vacuum packed in waterproof-plastic materials boxed for distribution. Aging happens during the transportation and/or storage of the packed chilled meat.

• Hanging Method- method of hanging the

carcass during aging and/or chilling has been found to affect tenderness as well. Common practice is to hang carcass by the heel of the hind leg.

• Electrical Stimulation- a practice of passing

electrical current (voltage vary from 30V to 1000V ) on the freshly slaughtered carcass. This practice accelerates the passing of rigor mortis. Some of the advantages cited are: prevention of cold shortening, improving color, tenderness and flavor.

• In-Vitro Enzyme Treatment- practice of giving

proteolytic enzymes to beef intended for slaughter is still one more method of achieving tender meat. Giving the live animal proteolytic enzymes such as papain or bromelin intravenously.

Mechanical MethodsPounding

- meat is pound until thin before drying. The action of pounding breaks the muscle fibers and connective tissues. This method of pre- preparation of fillet.

Slicing Thinly- slicing thinly cuts

the muscle fiber and makes chewing easier. This is applied to meat cuts intended for stir frying or sautéing.

Grinding/Chopping- chopping or grinding to

break the connective tissues and muscle fibers before forming patties or balls or any other desired shape.

Marinating - is intended primarily to

heighten or incorporate flavors in meat, but it has added effect of tendering.

Marinating solution contains an acid such as wine, vinegar, kalamansi, salt, and seasoning.

Use of Proteolytic Enzymes- proteolytic enzymes of plants or bacterial origin are used

in commercial meat tenderizing preparations. The enzymes acts on the muscle fibers making them shorter and more tender.

most commonly used plant enzymes are papain from papaya latex, bromelin from pineapple and ficin from figs.

Prolonged Simmering- most common way of tenderizing meat. The tenderizing

action is due to the conversion of collagen to gelatin.

Tenderizing and cookery ofmeat and poultry

Cooking meat achieves the following objectives:*Improve eating quality and digestibility,tenderization, food safety.*Enhance and develop flavors.*Brings about color changes makes the meat more tender and digestible.* Destroys parasites and pathogenic microorganisms that may be present making the meat safer for consumption.

Temperature

Pigment Protein Fiber

Protein-bound water

collagen

C F

38 100 Red Uncoiled, starts coagulation

Flow-out of muscle fiber

Solid

60 140 Red Continue coagulation

Continue to flow out

Begin to dissolve

71 160 Pink Mostly coagulated

Continue to dissolve

79 175 Brown-gray

Coagulated

Continue to dissolve

93 200 Brown-gray

Dense association

Dissolve rapidly

Effects on Cooking on Meat:

Constituents

Beef/Carabeef Cooking Methods

•Grilling. The cuts suitable for grilling are sirloin steak, rump steak, porterhouse steak, T-bone steak. Grilling must be preheated but racks should not be. Grease to prevent sticking. Turn meat once. Baste as needed.


•Roasting. Large cuts such as ribs and sirloin are best suited for roasting. Whole young calf may also be roasted. Baste the meat with its own drippings as it cooks to prevent from drying out. Internal temperature for rare is 55°C, and for medium 71°C, for well done 77°C.

Beef/Carabeef Cooking Methods •Pot Roasting. Beef cuts such

as flank, brisket, rump, top side, and silverside are suited for roasting. Use a very large pan with heavy lid. Brown first then place on a bed of vegetables; cover and cook under low heat for 45 minutes per half kilo. The covered pot may also be heated in a preheated oven at 165°C also at 45 minutes per half kilo.


•Pan Frying. Cuts suited for grilling may also be fried, the tender cuts cut into small/thin sections. Just enough fat to cover the bottom of the pan. Cook at high heat. Turn only once.


•Braising. Suitable for same cut as the those pot roasting (brisket, rump, sirloin, etc.). Brown meat first in small amount of fat. Use also a bed of vegetable but add some liquid. Cover and cook ovr loow heat for 2 to 3 hours


•Stewing. Used tough cuts of meat such as shin, chuck and flank. Also for tripe or pata. May or may not be coated with flour. May or may not be browned. May or may not use a bed of vegetables. Use small amount of liquid but replenish as needed. Cooking time up to 3 hours depending on cut used. May also be cooked in the covered pot inside the oven.

Pork Cooking Methods

•Grilling. Chops of all kinds can be grilled or fried.


•Roasting.All joints are suitable for roasting, even whole as in lechon. Cook to internal temperature of 77°C to insure safety.


•Stewing/Boiling. Suitable for all cuts as in sinigang.

Poultry Cooking Methods

•Grilling/Frying. All cuts including whole chicken and duck may be grilled or fried.


•Roasting. This is the most important way of cooking poultry, chicken eggs, goose, duck, and turkey. Cook to internal temperature of 75 °C. When roasting stuffed birds, cook the stuffing separately and stuff when the bird is cooked then cook a bit longer.


•Braising and Casseroling. Good method of cooking poultry. Suitable for older, tougher birds but may also be used for younger birds. May be applied to whole birds including turkey to shorten the time. In this case braising is done to fully cook the bird then roasted to brown the surface. This technique leads to less shrinkage.

Meat and PoultryStorage and Assessing Quality

How is Meat and Poultry Chilled and Maintained at the Plant?•Meat and poultry products are chilled

immediately after slaughter to acceptable internal temperatures which insure the prompt removal of the animal heat and preserve the wholesomeness of the products. Generally, red meat carcasses (which are above 90° F at the time of slaughter) are chilled in a blast cooler with rapidly moving chilled air, and, in some instances, a cold water shower.

•Poultry is required to be chilled to 40° F or less within specified time frames, depending upon the size of the carcass. Whole birds and parts of major size are chilled in ice or ice and water media. Poultry parts are chilled in ice, air or water spray with continuous drainage. Giblets must be chilled to 40° or below within two hours of slaughtering the birds.

How Does Packaging Prolong Storage Times?•Packaging is a physical barrier to cross

contamination. Microorganisms exist everywhere in nature. They are in the soil, air, and water. The simple act of covering food keeps microorganisms from contacting the food. Covered perishable foods can be stored longer and at better quality than uncovered foods. Modified atmosphere packaging (MAP) and vacuum packaging help prolong storage.

What Effect Does Vacuum Packaging and MAP Have on Meat Storage?• Oxygen in the air hastens both the chemical

breakdown and microbial spoilage of many foods. To help preserve foods longer, scientists have developed ways to help overcome the effects of oxygen. Vacuum packaging, for example, removes air from packages and produces a vacuum inside. MAP (modified atmosphere packaging) helps to preserve foods by replacing some or all of the oxygen in the air inside the package with other gases such as carbon dioxide or nitrogen. (examples: lunch meat in a blister package; raw beef brisket or filets in vacuum packaging; fresh turkeys).

Temperature for Raw Poultry• USDA's rules for labeling raw poultry products as to

their storage temperature became effective on December 1997. The term "fresh" may ONLY be placed on raw poultry that has never been below 26° F. Poultry held at 0° or below must be labeled "frozen" or "previously frozen." No specific labeling is required on poultry between 0 and 26° F.

• This poultry label rule addresses a truth-in-labeling issue, not food safety, because most pathogenic bacteria do not grow or grow very slowly at normal refrigerator temperatures. The Agency concluded that the term "fresh" should not be used on the labeling of raw poultry products that have been chilled to the point they are hard to the touch.

During Transportation• To prevent rapid growth of pathogenic bacteria,

perishable meat and poultry products should be kept cold (40° or below) or frozen (0° or below) during transport from the plant to a refrigerated warehouse or retail store. Microorganisms capable of causing food-borne illness either don't grow or grow very slowly at refrigerated temperatures of 40°F. Freezing keeps food safe by slowing the movement of molecules, causing any microbes present to enter a dormant stage. There's also no risk of dripping juices to contaminate nearby products and storage areas.

REFRIGERATOR HOME STORAGE (at 40° F or below) OF FRESH OR UNCOOKED PRODUCTS

REFRIGERATOR HOME STORAGE (40° F or below) OF PROCESSED PRODUCTS SEALED AT PLANT

Assessing Quality•The quality of meat and poultry products

is appreciated through sensory impressions, and therefore its assessment is very subjective. However, it is known that there are objective traits very important for the final properties of meat; this includes the breed and feeding of animals, weight of carcasses, and aging of meat after slaughter.

•In general, the success of sensory analysis relies on the capability to identify, with a precise description, a kind of product that should be reproducible as many times as we need to be tested for as many consumers as possible.

•Notice that from each animal, there are only a limited amount of similar pieces of meat, and thus we can only provide pieces of a given breed, weight, and aging period.

Meat Safety

The safety of meat in the Philippines is the responsibility of the national meat inspection service, an agency of the department of agriculture. Republic act 9296 signed into law in may 2004, embodies the protection of human and animal health against hazards in meat, from farm produce to processes meats. The law specifically mentions the application of the HACCP approach to ensure meat safety.

The NMIS have put in place a system of accrediting slaughterhouses and dressing plants in the country. Those with AAA accreditation are allowed to export their products; those with AA are allowed to bring the meat to other provinces and regions in the country. Those with A rating are allowed to sell within the province. Unfortunately, there are still many slaughterhouses that have not been accredited. Furthermore, in many communities animals may be slaughtered even without the benefit of sanitary inspector.

Key concerns of fresh meat safety are: presence of parasites contamination with pathogens due to improper slaughter methods and unsanitary handling. For cooked meat the issues may be undercooked meat especially lechon.

ParasitesRoutine meat inspection looks for

signs of parasitic infection so heavily infested meats are condemned. Parasites undetected during such routine examination are easily killed by adequate cooking.

Safe cooking TemperaturesThe USDA has lowered the recommended safe cooking temperature for whole cuts of pork ,steaks, roasts, and chops from 160 F to 145 F but added a three minute rest time before carving or consuming. The safe temperature for cuts of beef, veal and lamb remains unchanged at 145 F, but a three minute rest time is added as part of its cooking. Ground beef, veal, lamb and pork should be cooked to 160 F and do not require a rest time the safe cooking t poultry products, including ground chicken and turkey remains at 165F.

Using ThermometerWith most thermometer, position the probe in the thickest part of the meat cut away from fat bone or gristle. For beef burgers chicken pieces pork chops, meat loaves, roast and casseroles take the food away from the heat when the meat is almost done. Remember the large pieces of food have the residual heat. Position the probe of the thermometer in the thickest part of the piece but take extra precaution not to hit the bone. You do not want to take the temperature of the bone which will tend to have higher temperature than the meat part.

Safe storageMeats are among the most perishable foods. This ready perishability makes it a potentially hazardous food. At ambient temperatures meat spoils so fast. It is therefore necessary to keep it in chilled storage.

References:•Basic Foods for Filipinos (3rd and 4th

Edition)•Understanding Foods by Amy Brown•Professional Cooking by Wayne Gislen•http://www.peta.org/action/10-surprising-f

acts-chickens/•http://mainstreetmeats.com/health-facts-a

bout-meat/•http://www.medterms.com/script/main/art

.asp?articlekey=38316

http://www.peta.org/action/10-surprising-facts-chickens/

http://www.peta.org/action/10-surprising-facts-chickens/

http://mainstreetmeats.com/health-facts-about-meat/

http://mainstreetmeats.com/health-facts-about-meat/

http://www.medterms.com/script/main/art.asp?articlekey=38316

http://www.medterms.com/script/main/art.asp?articlekey=38316