Crop milk
Encyclopedia
Crop milk is a secretion from the lining of the crop
Crop (anatomy)
A crop is a thin-walled expanded portion of the alimentary tract used for the storage of food prior to digestion that is found in many animals, including gastropods, earthworms, leeches, insects, birds, and even some dinosaurs.- Bees :Cropping is used by bees to temporarily store nectar of flowers...

 of parent birds that is regurgitated
Regurgitation (digestion)
Regurgitation is the expulsion of material from the mouth, pharynx, or esophagus, usually characterized by the presence of undigested food or blood.Regurgitation is used by a number of species to feed their young...

 to young birds. They are found among all pigeons and doves where they are referred to as pigeon milk. Crop milk is also produced by flamingos and some penguins.

Comparison to milk

Crop milk bears little resemblance to mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

ian milk
Milk
Milk is a white liquid produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals before they are able to digest other types of food. Early-lactation milk contains colostrum, which carries the mother's antibodies to the baby and can reduce the risk of many...

, being a semi-solid substance somewhat like pale yellow cottage cheese
Cottage cheese
Cottage cheese is a cheese curd product with a mild flavor. It is drained, but not pressed, so some whey remains and the individual curds remain loose. The curd is usually washed to remove acidity, giving sweet curd cheese. It is not aged or colored. Different styles of cottage cheese are made from...

. It is extremely high in protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 and fat
Fat
Fats consist of a wide group of compounds that are generally soluble in organic solvents and generally insoluble in water. Chemically, fats are triglycerides, triesters of glycerol and any of several fatty acids. Fats may be either solid or liquid at room temperature, depending on their structure...

 and contains more of it than cow or human milk.It has also been shown to contain anti-oxidants and immune-enhancing factors. Both male and female adult birds produce crop milk and share in the feeding and care of the young.

Feeding nestlings

Pigeon's milk begins to be produced a couple of days before the eggs
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...

 are due to hatch. The parents may cease to eat at this point in order to be able to provide the squabs (baby pigeons and doves) with milk uncontaminated by seeds, which the very young squabs would be unable to digest. The baby squabs are fed on pure crop milk for the first week or so of life. After this the parents begin to introduce a proportion of adult food, softened by spending time in the moist conditions of the adult crop, into the mix fed to the squabs, until by the end of the second week they are being fed entirely on softened adult food.

Pigeons normally lay two eggs. If one egg fails to hatch, the surviving squab gets the advantage of a supply of crop milk sufficient for two squabs, and by the end of the first week it is almost as big as two "normal" squabs would be.

Hand-rearing pigeon squabs

The very high nutrient concentration of pigeon's milk makes it difficult to devise an artificial substitute for hand-rearing squabs. Various proprietary mixes are available. A good home-made mix can be made from equal quantities of dehydrated dried pure soy
Soybean
The soybean or soya bean is a species of legume native to East Asia, widely grown for its edible bean which has numerous uses...

 protein (with no added salt, flavorings, preservatives etc.) and soy-based dairy-free butter
Butter
Butter is a dairy product made by churning fresh or fermented cream or milk. It is generally used as a spread and a condiment, as well as in cooking applications, such as baking, sauce making, and pan frying...

-substitute (ordinary dairy butter is not suitable, as young squabs' digestive systems cannot cope with dairy products). This is made into a runny paste with a little water, a tiny crumb of a multivitamin
Multivitamin
A multivitamin is a preparation intended to supplement a human diet with vitamins, dietary minerals, and other nutritional elements. Such preparations are available in the form of tablets, capsules, pastilles, powders, liquids, and injectable formulations...

 tablet and a tiny pinch of chalk
Chalk
Chalk is a soft, white, porous sedimentary rock, a form of limestone composed of the mineral calcite. Calcite is calcium carbonate or CaCO3. It forms under reasonably deep marine conditions from the gradual accumulation of minute calcite plates shed from micro-organisms called coccolithophores....

 (which is necessary for bone development to avoid splay-leg). The crop should be allowed to empty completely between feedings. With care and gentleness, it is possible to raise a pigeon on this mix from the moment of hatching.

Cultural references

  • In Animal Crossing: Wild World
    Animal Crossing: Wild World
    is a 2005 social simulation video game developed and published by Nintendo for the Nintendo DS handheld game console, and is the second game in the Animal Crossing series....

     for the Nintendo DS
    Nintendo DS
    The is a portable game console produced by Nintendo, first released on November 21, 2004. A distinctive feature of the system is the presence of two separate LCD screens, the lower of which is a touchscreen, encompassed within a clamshell design, similar to the Game Boy Advance SP...

     and Animal Crossing: City Folk for the Wii
    Wii
    The Wii is a home video game console released by Nintendo on November 19, 2006. As a seventh-generation console, the Wii primarily competes with Microsoft's Xbox 360 and Sony's PlayStation 3. Nintendo states that its console targets a broader demographic than that of the two others...

    , a character named Brewster uses it as an ingredient when serving coffee
    Coffee
    Coffee is a brewed beverage with a dark,init brooo acidic flavor prepared from the roasted seeds of the coffee plant, colloquially called coffee beans. The beans are found in coffee cherries, which grow on trees cultivated in over 70 countries, primarily in equatorial Latin America, Southeast Asia,...

     to long-time customers.
  • In the reality TV series Flavor of Love
    Flavor of Love
    Flavor of Love is an American reality television dating game show parody starring Flavor Flav of the rap group Public Enemy.While not a direct spin-off, the show was a result of Brigitte Nielsen and Flavor Flav's failed relationship on Strange Love, as well as The Surreal Life...

     during Season 2, the father of Deelishis requests a crate of pigeon milk at dinner.
  • Ptasie mleczko
    Ptasie mleczko
    Ptasie mleczko ® , Ptichye Moloko , ptashyne moloko , which translates literally as "bird milk" , is a soft chocolate-covered candy filled with soft meringue...

    is the name of Polish
    Poland
    Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...

     candy, which variations are also popular in Eastern Europe
    Eastern Europe
    Eastern Europe is the eastern part of Europe. The term has widely disparate geopolitical, geographical, cultural and socioeconomic readings, which makes it highly context-dependent and even volatile, and there are "almost as many definitions of Eastern Europe as there are scholars of the region"...

    countries as Ptichye Moloko (Russian: птичье молоко), ptashyne moloko (Ukrainian: птaшине молоко).

External links

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