Crop milk

Crop milk
One Greater Flamingo-chick in Zoo Basel is fed on crop milk.

Crop milk is a secretion from the lining of the crop of parent birds that is regurgitated 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.[1][2][3]

Contents

Comparison to milk

Crop milk bears little resemblance to mammalian milk, being a semi-solid substance somewhat like pale yellow cottage cheese. It is extremely high in protein and fat and contains more of it than cow or human milk.[4]It has also been shown to contain anti-oxidants and immune-enhancing factors. [5] 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 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 protein (with no added salt, flavorings, preservatives etc.) and soy-based dairy-free butter-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 tablet and a tiny pinch of chalk (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.[citation needed]

Cultural references

References

  1. ^ Levi, Wendell (1977). The Pigeon. Sumter, S.C.: Levi Publishing Co, Inc. ISBN 0-85390-013-2. 
  2. ^ Silver, Rae (1984). "Prolactin and Parenting in the Pigeon Family". The Journal of Experimental Zoology 232: 617–625. http://www.columbiauniversity.org/cu/psychology/silver/publications/035Silver%201984.PDF. 
  3. ^ Eraud, C., Dorie, A., Jacquet, A. and Faivre, B. (2008). "The crop milk: a potential new route for carotenoid-mediated parental effects". Journal of Avian Biology 39: 247–251. doi:10.1111/j.0908-8857.2008.04053.x. 
  4. ^ Bird Milk
  5. ^ "Mysteries of pigeon milk explained" Retrieved September 22, 2011

External links


Wikimedia Foundation. 2010.

Игры ⚽ Нужно решить контрольную?

Look at other dictionaries:

  • crop milk — a liquid secreted in the crop of certain adult pigeons and fed to their newly hatched young. Also called pigeon milk. * * * crop milk, a liquid secreted by the lining of a pigeon s or dove s crop during the brooding period: »In about 14 days the… …   Useful english dictionary

  • crop milk — a liquid secreted in the crop of certain adult pigeons and fed to their newly hatched young. Also called pigeon milk. * * * …   Universalium

  • crop-milk — ˈ ̷ ̷ˌ ̷ ̷ noun : a secretion resembling milk that is produced in the crop of certain pigeons and doves and used to feed the young …   Useful english dictionary

  • Milk — For other uses, see Milk (disambiguation). Foremilk and Hindmilk samples of human breast milk …   Wikipedia

  • Crop (anatomy) — This article is about the digestive croup. For the top of the hindquarters, also known as the croup, see Rump (animal). A male Budgerigar with a full crop after feeding …   Wikipedia

  • Crop circle — For the irrigation method that produces circular fields of crops, see center pivot irrigation. A 780 ft (240 m) crop circle in the form of a double (six sided) triskelion composed of 409 circles. Milk Hill, England, 2001 A crop circle… …   Wikipedia

  • Crop rotation — Fallow redirects here. For other uses, see Fallow (disambiguation). Satellite image of circular crop fields in late June 2001. Healthy, growing crops are green. Corn would be growing into leafy stalks by then. Sorghum, which resembles corn, grows …   Wikipedia

  • Crop — For other uses, see Crop (disambiguation). Domesticated plants …   Wikipedia

  • pigeon milk. — See crop milk. [1885 90] * * * …   Universalium

  • pigeon milk. — See crop milk. [1885 90] …   Useful english dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”