This seems to be a subject that comes up a lot and has been for years. Hopefully this information will help some of you in making the decision to use or not use grit as a part of your cockatiel’s diet.Cockatiels and other parrot type birds don’t need grit in their diet. In fact if these birds eat grit on a free choice basis, they can end up with their crop, proventriculus, or ventriculus (digestive system) impacted with it from over consumption. Most cases of over-consuption are in birds that were ill but….if the system won’t digest the grit, eventually it will become overloaded/impacted even in a healthy bird.
Studies have shown that this type of impaction is not a problem in areas such as New Zealand and Australia. From what some of my friends from those areas have said, what they refer to as grit is ground up oyster shell. The birds body can digest ground up shells, but….if taken from contaminated water, it could contain high toxin levels. What we in the U.S. refer to as grit is generally a sand/gravel type mixture which sometimes has charcoal in it. (according to Avian Medicine: Principles and Applications, charcoal that is used in some grit mixtures may interfere with the absorption of vitamins A, B2 and K and can contribute to these vitamin deficiencies in some birds). A hookbill (parrot type) bird’s digestive system can not process gravel/sand so in over consuming grit, can become blocked.
Other potential sources of problems with impaction from grit/sand could be using sandpaper perch covers, sandpaper cage liners, some of the cheaper cement perches, access to bricks or cement blocks, and using toys made from lava rock (if your bird chews on the rock and ingests any of it).
Generally grit/gravel is eaten in the wild by birds that eat whole seeds (such as pigeons, doves, etc.). Cockatiels (unless they are ill) don’t eat whole seeds (they remove the husks, shells). Birds which eat whole seeds needed the gravel to grind the food in the crop. Cockatiels and other parrot type (hookbill) birds don’t need grit since their digestive enzymes will work on the foods they eat since they don’t eat the shells/hulls.