Originally published in Pet Gazette, April/May 2013
The eye-catching packaging with a brightly colored bird makes bird owners’ wonder if they should buy some. Understanding what grit is, its purpose, and the possible problems it could cause, can help owners make an educated decision about offering grit to their bird.
The Purpose of Grit
“Grit is used by birds to aid in digestion of seeds” is a sentence seen repeatedly in both outdated parrot care books and other related texts. But it fails to convey that grit is used to aid in the digestion of whole, intact seeds. Parrots’ digestive enzymes work amazingly well in digesting the inner portion of the seeds, but can have difficulty in breaking down the hull – the fibrous outer coating. Grit, in the avian ventriculus, aids in grinding and wearing away the hull, enabling the digestive enzymes to reach the nutrients within.
What Exactly Is Grit?
Two groups of substances are called grit – soluble and insoluble. Insoluble grit, the type discussed here, is composed of minute substances such as sandstones and other minerals often found in dirt and clays. It cannot be digested and will remain in the body until expelled.
Soluble grit is organic, and can include crushed shells, often oyster shells or cuttlebone. Since soluble grit is mostly calcium carbonate, it is easily digested by the acids in the proventriculus and poses little danger of accumulating in the digestive system. However, while soluble grit can offer an alternative source of seeds.
Do Birds Really Require Grit?
Only birds such as doves, which consume seeds intact, require grit in their diet. Birds such as parrots, and even finches and canaries, hull their seeds, so do not need the extra aid grit would provide. In fact, some species of parrots have ridges inside their upper beak that can hold the seed in place while the lower beak cracks and removes the hull. Birds on a pelleted diet should also not require grit. In the US, the use of grit is generally discouraged, especially if offered freely, which may lead to obstructive gastritis. In Australia, however, grit is commonly given to pet birds, and few problems have been reported. At the moment, there is no explanation for these interesting geographical differences.
If given freely, some birds may over- consume grit products, leading to a possibility of impaction. And some commercially- made grit products contain charcoal, which can affect the absorption of vitamins, resulting in deficiencies.
In conclusion, the benefit of grit for parrots and softbills has not been positively demonstrated. While there are both potential risks and potential benefits, we recommend offering grit in moderation, if offered at all.