Grit (supplement)

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Grit is a material eaten by birds to aid in their diets and digestion. Wild birds find grit naturally while foraging, and farmers can purchase grit for their domestic fowl.

Contents

Composition

There are two kinds of grit:

Soluble grit dissolves in a bird's digestive system. It is usually made from calcium-high materials; the calcium helps the bird in egg shell production. Soluble grit can be made from limestone or coarsely ground or broken seashells, like oyster or mussel shells; this kind of grit is also called shell grit. [1] Other uses for shell grit include protecting plants from slugs or snails [2] and for aquariums.

Insoluble grit consists mainly of crushed stone (though often with additives). These do not dissolve in the bird's digestive system; instead, they remain in the gizzard for weeks or months to help the bird grind up its food for digestion. Stones used may include quartz, granite, feldspar, and phosphate rock. [3] Insoluble grit is found in the gizzards of birds that eat plant parts and some that eat invertebrates. Because of its grinding function, this kind of grit is sometimes called "hen's teeth." [4]

The size of grit particles varies widely by species, from less than 0.1 millimeter in diameter to, in the case of larger birds like ostriches, over 2.5 cm in diameter. Juvenile birds will often ingest smaller pieces of grit than adults, as in Sarus Cranes. [5] Grit size also varies with birds' diet; larger grit helps birds grind down harder, coarser food more efficiently. The kind of grit used may also change seasonally, whether due to varying availability of grit or varying availability of food to be digested. Sex and reproductive status are usually not associated with grit size. Grit that starts off in rough or angular pieces may become rounded off as it is used in a bird's gizzard. [4]

History

Grit has been known to avian researchers since at least the late 1700s. United States federal and state researchers began dedicating significant attention to grit by the start of the 1900s. [4]

Grit use has been studied in poultry, wild gallinaceous birds, and waterfowl. For poultry, the aim has been to improve the output of poultry and egg farms. For waterfowl and gallinaceous birds, there have been many avenues of research: their status as game birds, their population densities, any potential role of grit in lead poisoning, and pesticides that grit may include. [4]

Related Research Articles

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<span class="mw-page-title-main">Crane (bird)</span> Family of large, long-legged birds

Cranes are a type of large bird with long legs and necks in the biological family Gruidae of the order Gruiformes. The family has 15 species placed in four genera which are Antigone, Balearica, Leucogeranus, and Grus. They are large birds with long necks and legs, a tapering form, and long secondary feathers on the wing that project over the tail. Most species have muted gray or white plumages, marked with black, and red bare patches on the face, but the crowned cranes of the genus Balearica have vibrantly-coloured wings and golden "crowns" of feathers. Cranes fly with their necks extended outwards instead of bent into an S-shape and their long legs outstretched.

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<span class="mw-page-title-main">Gizzard</span> Digestive organ of some animals

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<span class="mw-page-title-main">Gastrolith</span> Rock held inside the intestinal tract

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Grit, Grits, or Gritty may refer to:

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  1. Receive raw ingredients: Feed mills receive raw ingredients from suppliers. Upon arrival, the ingredients are weighed, tested and analyzed for various nutrients and to ensure their quality and safety.
  2. Create a formula: Nutritionists work side by side with scientists to formulate nutritionally sound and balanced diets for livestock, poultry, aquaculture and pets. This is a complex process, as every species has different nutritional requirements.
  3. Mix ingredients: Once the formula is determined, the mill mixes the ingredients to create a finished product.
  4. Package and label: Manufacturers determine the best way to ship the product. If it is prepared for retail, it will be "bagged and tagged," or placed into a bag with a label that includes the product's purpose, ingredients and instructions. If the product is prepared for commercial use, it will be shipped in bulk.

References

  1. Holderread, Dave (19 January 2011). Storey's Guide to Raising Ducks, 2nd Edition: Breeds, Care, Health. Storey Publishing. ISBN   9781603427456.
  2. Snails, Shell grit & Liliums - Gardening in Oz Forum - GardenWeb Archived February 5, 2012, at the Wayback Machine
  3. Roberts, Howard Armstrong (1918). Commercial Poultry Raising: A Thoroughly Practical and Complete Reference Work for the Amateur, Fancier Or General Farmer, Especially Adapted to the Commercial Poultryman. D. McKay.
  4. 1 2 3 4 Current Ornithology. Springer US. 29 June 2013. ISBN   9781475749014 . Retrieved 13 April 2023.
  5. Sundar, K. S. Gopi (2005). "Grit use in the Sarus Crane Grus antigone". Journal of the Bombay Natural History Society. 102 (1): 106–109.