Gizzard

Duck gizzards

The gizzard, also referred to as the ventriculus, gastric mill, and gigerium, is an organ found in the digestive tract of some animals, including birds, reptiles, earthworms and some fish. This specialized stomach constructed of thick, muscular walls is used for grinding up food. In certain insects and mollusks, the gizzard features chitinous plates or teeth.

Etymology

The word "gizzard" comes from the Middle English giser, which derives from a similar word in Old French, which itself evolved from the Latin gigeria, meaning giblets. The Latin word probably derives from a common Proto-Indo-European source with the Persian word for liver, which is "jiger".

Structure

Birds swallow food and store it in their crop if necessary. Then the food passes into their glandular stomach, also called the proventriculus, which is also sometimes referred to as the true stomach. This is the secretory part of the stomach. Then the food passes into the ventriculus (also known as the muscular stomach or gizzard). The gizzard can grind the food with stones that have been swallowed and pass it back to the true stomach and vice versa. Bird gizzards are lined with a tough layer made of the carbohydrate-protein complex koilin, to protect the muscles in the gizzard and to aid in digestion.

Gizzard stones

Some animals that lack teeth will swallow stones or grit to aid in digestion. All birds have gizzards, but not all will swallow stones or grit. The birds that do, employ the following method of 'mastication':

"A bird swallows small bits of gravel that act as 'teeth' in the gizzard, breaking down hard food such as seeds and thus helping digestion." (Solomon et al., 2002).

These stones are called gizzard stones or gastroliths and are usually smooth and round from the polishing action in the animal's stomach. When too smooth to do their required work, they may be passed or regurgitated.

Animals with gizzards

All birds have gizzards. The gizzards of emus, turkeys and chickens are most noteable in cuisine (see below). The mullet (Mugilidae) found in estuarine waters worldwide, and the gizzard or mud shad, found in freshwater lakes and streams from New York to Mexico, have gizzards. The gillaroo (Salmo stomachius), a richly colored species of trout found in lough Melvin in County Fermangh, has a gizzard which is used to aid the digestion of water snails, the main component of its diet. The crocodile also has a gizzard.

Dinosaurs with gizzards

Dinosaurs believed to have had gizzards based on the discovery of gizzard stones recovered near fossils:

• Psittacosaurus
• Massospondylus
• Sellosaurus
• Omeisaurus
• Apatosaurus
• Barosaurus
• Dicraeosaurus
• Seismosaurus

In cuisine

Fried gizzards and livers

Poultry gizzards are a popular food throughout the world. Grilled chicken gizzards are sold as street food in Haiti and throughout Southeast Asia. In Indonesia, gizzard and liver are considered as part of a complete fried poultry dish. Stewed gizzards are eaten as a snack in Portugal, while pickled turkey gizzards are a traditional food in some parts of the Midwestern United States. In Hungary it is made with paprika. In the Southern United States, the gizzard is typically served fried, sometimes eaten with hot or honey mustard, or added to crawfish boil along with crawfish sauce, and it is also used in traditional New Orleans gumbo. In Chicago, gizzard is battered, deep fried and served with fries and sauce. Gizzard and mashed potato is a popular food in many European countries. In France, especially the Dordogne region, gizzards are eaten in the traditional Perigordian Salad, along with walnuts, croutons and lettuce. The Chamber of Commerce in Potterville, Michigan have held a Gizzard Fest each June since 2000; a gizzard-eating contest is among the weekend's events.

The word "Sangdana" is commonly used to refer to chicken gizzards in Pakistan. The word is derived from Persian( Sang = stone and dana = grain). It may be served cooked in a curry while barbecued skewered gizzards are also popular.

In Yiddish, gizzards are referred to as "pipik'lach", literally meaning navels. The gizzards of kosher species of birds have a green or yellowish membrane lining the inside, which must be peeled off before cooking, as it lends a very bitter taste to the food. In traditional Eastern European Jewish cuisine, the gizzards, necks, and feet of chickens were often cooked together, although not the liver, which per Kosher law must be broiled.

In Uganda, Cameroon and Nigeria, the gizzard of a cooked chicken is traditionally set aside for the oldest or most respected male at the table.

Giblets consist of the heart, liver and gizzard of a bird, and are often eaten themselves or used as the basis for a soup or stock.

Some people put chicken gizzards in their dressing around holiday time.

References

• Solomon, E.P., Berg L.P., and Martin D.W., 2002. Biology Sixth Edition. Thomson Learning Inc., Australia, Canada, Mexico, Singapore, Spain, United Kingdom, United States pp. 664
• Dyce, Sack, Wensing, 2002. Textbook of Veterinary Anatomy Third Edition, Saunders. ISBN 0-7216-8966-3