Diet

 
  Grit

Hookbills neither require or naturally seek out any source of grit,
whether it be silica based or soluble mineral based.  Do not confuse
this with the needs of certain macaws who eat clay to supplement lacking
minerals in their native diets.

In my humble opinion, grit of any nature does not belong anywhere in the parrot diet or environment.  They are simply not equipped physiologically to process it.  With the documented problems of GI impaction and irritation, why should this even be a consideration?  From the perspective of soluble mineral grits, the overriding factor should be if the bird suffers from a deficiency in these minerals.  If so, supplementation would be the logical and sensible alternative.  I personally can see no reason to ask for problems.
Patrick Thrush

Almost all Australian parrots have access to grit.  This probably horrifies all you North Americans.  But before you get me up before the animal cruelty groups, we NEVER, I repeat, NEVER, see any problems with grit.  My vet, President of the Australian chapter of AAV, has only ever seen two instances of impacted crops in 15 years of practice.

One was a tiel with a crop full of human hair from over preening
his owner, and the other a lorikeet which had gone crazy with mango (understandable) and had a crop full of mango fibres.  It is one of the great mysteries of aviculture why North American parrots are apparently so willing to get their crops full of grit and suffer impaction, while Australian birds never get this problem.  

My own theory is that our birds are just more intelligent!<G>  I do know that every parrot I have autopsied has had some grit in its gizzard, and I believe that grit does help the bird to more efficiently grind up the seed in the gizzard, thus reducing physiological stress.  Also all wild parrots apparently
have been found to have some grit in their gizzard, and I don't think they would swallow it if they didn't find it useful.  I do acknowledge that grit is not essential, but I do believe it is useful.  So, grit is a mystery, even RHH comment on the paradox, and the latest edition of Australia's text on bird health, "Everybird" 1994 edition, still recommends that grit be made available, which we do without problem.

I must start out by emphasizing that my comments refer only to those species of parrots I am personally familiar with, that is the Australian parrots, Lovebirds, and Asiatics.  Unfortunately Macaws, Amazons, and many other species of non-Australian parrots are extremely rare here in Australia, and outside my price range to keep.

I can assure those doubting that wild parrots intentionally consume grit that, from my own observatons, they do deliberately pick up and swallow grit.   I  have watched flocks of Corellas, Galahs, Major Mitchells, budgies, and other species, deliberately land on sand banks in dry inland river beds and peck away and swallow sand grains.  It is a deliberate action on their part.  In addition we all know the incredible ability of parrots to manipulate even very small seeds with their beak and tongue, while husking and then swallowing the seed. Given that ability, it is highly unlikely that a wild parrot would accidentally swallow grit.

What is surprising is the large amount of grit usually to be found in the gizzard of an autopsied wild parrot.  A Rosella for instance might have up to 50 grains of grit in the gizzard.  These range in size from perhaps white French millet size, down to almost microscopic size - presumably reflecting the amount of wear that the grain has undergone.  At a recent Parrot Convention held in Grafton that I attended, one talk was by an avian vet, and was a demonstration of how to autopsy a parrot.  The "victim" was a road kill Galah, and it's gizzard had a pile of grit in it - almost half filled!

Birds that do not hull their seed such as finches, doves and quail have to have grit to properly digest their seed.  Finches will die from starvation if they don't have grit in their gizzard.  As for how the practice of giving grit to parrots started, I would think it far more likely that it was as a result of both watching wild parrots and seeing what was in the bird's gizzard when
wild parrots were dissected.  

Actually when an autopsy is done on a seed-eating parrot, it is surprising just how much seed seems to be swallowed unhusked. Some birds might have 20% or more of the seed in their crop which is unhusked, particularly the smaller millets and pannicums.

Parrots can certainly live their whole lives without grit.  The question is whether having a significant amount of grit helps that bird to have a less-stressed (= more efficient) digestive system.  I believe that it does. Anything that makes it easier, and more efficient for the bird to grind up the seed before the digestive system gets to work must be a help to the bird.

This idea that a sick bird will gorge on grit is a common one in the USA - all I can say is that I have never, ever, come across such a case. I have never seen an autopsied parrot with a gizzard full of grit and never seen grit at all in the proventriculus.  I also find it incredible that a single vet in Florida sees hundreds of grit impaction cases a year, while Australian vets see none!
Something is wrong here. Perhaps with USA vets not having exposure to wild parrot autopsies, they are not used to the large amount of grit that can occur in healthy wild birds. What they are diagnosing as gizzard impaction, to Australian vets might be a healthy and normal grit load for a bird.

My mention of crop impaction was solely because no case of gizzard impaction was seen, although some of the list stories from the USA do refer to crop impaction due to grit being a problem.

One could get speculative here, so here goes! While parrots can digest their food without grit, perhaps birds have indeed died from "grit deficiency". Perhaps, as some later replies have alluded to, an absence of grit might lead to a long term digestive system problem due to inefficient absorption of nutrients due to inefficient grinding of seed.  Such a deficiency may never show up as a primary cause of early death, but may result in a depressed immune system, and result in a bird having an earlier death than it should have.  One could speculate in all sorts of directions here, but it will remain purely speculation.  Even designing an experiment to test that hypothesis is daunting, never mind funding the 20 year lifespan of a project which would involve hundreds of birds!

Some comment has been made about possible compositional differences in the grit provided.  I don't believe that is of any relevance.  The grit used by Australians tends to be whatever is handy.  As long as it is small (about millet size) then it doesn't seem to matter, if it is quartz, crushed volcanic rock or any other rock.  Some use river sand, others beach sand, and others quarry crushings.  My mix - a local river sand sold by landscape yards - is probably about 75% silica, with the rest being a real mixture.  As I mentioned previously, crushed shell grit is useful only as a calcium source, it dissolves too quickly, and is too soft, to be of value in gizzard grinding.

While I am happy and relaxed about giving my birds unlimited access to grit, I neither encourage nor discourage anyone else to provide grit.  It is a choice that has to be made by each individual, like the choice to feed pellets or seed (or neither!).  And, as always, if in doubt - DON'T.
cheers,
Mike Owen
Queensland
Australian Rep.
World Parrot Trust.

Most avian veterinarians and aviculturalists in the U.S. no longer
recommend feeding grit to birds. No one is even sure that birds in the wild "purposely" consume grit, even though small gravels and sand have been found in the contents of the proventriculus and gizzard of various wild parrot specimens. Some think that these gravel and sand particles could be debris that was stuck to food eaten from the ground or other surfaces.

The original idea of offering grit to parrots is thought to have been borrowed from poultry. Chickens and turkeys do need small bits of sand to grind off the hard outer coatings of seeds in order to digest them but parrots crack the seeds they eat before swallowing them. Not only do parrots use their beak and tongue to crack seeds and prepare them for digestion, they have hard ridge-like structures on the base of the upper beak and inside the mouth to aid in crushing hard food.

Birds have one stomach divided into two sections. The proventriculus is the "true" stomach and it adds digestive juices to the food. The second part is the gizzard (ventriculus)--a muscular stomach that grinds and pulverizes the food as it moves through the organ. Considering that so many birds have
lived their entire lives without ever consuming grit and without developing digestive problems, the gizzards of parrots that crack their seeds obviously are capable of accomplishing their task without the benefit of grit.

As Mike said, Dr. Harrison wrote about the fact that the feeding of grit is controversial and he wrote that it is "viewed with disfavor in the U.S. but frequently offered to companion birds in Australia with few ill effects". He goes on to say that birds fed "formulated diets" (pellets) are unlikely to need grit. He further states that as a compromise, a Cockatiel-sized bird can be offered five grains of grit biannually and a Cockatoo-sized
bird can be offered a half-teaspoon of grit biannually. Dr. Gary
Gallerstein recommends that smaller softbill species such as Canaries and Finches get two pieces of grit per week.

The most serious problems of feeding grit to parrots occur when a bird that is sick, and therefore has an abnormal or "deranged" appetite, has access to unlimited grit. Dr. Joel Murphy, holistic vet of Tampa, Florida and author of HOW TO CARE FOR YOUR PET BIRD, says that he treats hundreds of cases of grit impaction every year at his clinic. He said that whenever a parrot has a case of "indigestion", and a bowl of grit is available, the bird usually eats enough grit to fill the gizzard and often the
proventriculus too. He said that he doubts that a parrot in the jungle would find that many small rocks to consume at once if they had a similar digestive upset, and that the effect of eating this large amount of grit is like a person eating enough gravel to fill his stomach, and often results in death.  He recommends not feeding grit at all but says that if you do, you should not give more than two pieces of grit to a bird in a six month
period.

Since Mike's vet in Australia has seen only two instances of impacted crop in 15 years of practice, I am very curious about the difference in numbers between Dr. Murphy's "hundreds of cases a year" and Mike's vet's experience. It would be interesting if we could poll Avian vets in both countries. I have a feeling that neither of these numbers are "average".
Maybe there is a difference in the type and/or size of grit fed in the U.S. and Australia. Obviously, something is different!  Could we be talking about two different parts of the anatomy? Mike mentions "crop impaction" while U.S. literature mentions proventricular and ventricular impaction.

A parrot owner who worries about grit impaction might keep in mind that parrots can and do digest their food without grit. There are many Avian medical problems that we cannot prevent, but this is a problem that can be avoided. Also, it is worth noting that while birds have died due to crop or
gastrointestinal impaction, no birds have died of a "grit deficiency". This should be of some comfort to those bird owners who are uncomfortable with the idea of offering grit to their birds.  If one does decide to feed grit, soluble grit is said to be preferable since it eventually will dissolve and pass out of the bird's system. Impaction of the gizzard will frequently resolve on its own with the help of  X-rays and endoscopy for diagnosis of
the problem, and supportive care and antibiotics. Surgery of the gizzard is difficult and is considered only after all other treatment modalities fail.

Dr. Robert Linville, DVM of Vallejo, California states, "Birds that hull their seeds do not require grit. Although they seem to enjoy picking at it, overeating grit can irritate and even obstruct the gastrointestinal tract. If grit is used, it should be provided in very small amounts. A few grains of grit a week is more than enough. We recommend a firm no-grit policy (exception is passerine birds such as Finches and Canaries)."

Since the benefits of feeding grit are an unknown, and the chance for impaction is a known risk, it seems that free choice feeding of grit to the larger parrot species might not be justifiable. Perhaps a happy medium could be reached by using only the vet-prescribed amounts of grit for the specific bird species detailed above, rather than the free choice feeding
of grit for all parrots.
Carolyn Swicegood 

Maybe there is a nutritional link in the grit problem.  Australian birds, on the whole, are fed very differently to American birds and as Mike pointed out many Australians use sand on the bottom of their cages.

Using sand as a grit source would provide silica.  Speaking as a naturopath (because I'm definitely not a bird expert), silica is the mineral that controls the distribution and absorption of calcium (which is why re-mineralizing formulas for arthritis contain silica).  Silica is also the mineral for "removing pathogenic waste".

A bird that became impacted from over-indulging in sand/grit could be instinctively trying to normalise it's mineral balance.

Children (and animals) that eat dirt are treated with the Celloid mineral Calc. phos. or homoeopathic Calc. carb. which would again imply a link with the calcium/mineral balance.

I wouldn't discard nutrition as a cause of excess grit intake.  I wonder what the diet is of these birds that suffer impaction from grit?  Do birds that receive mainly a seed diet have the same incidence of this?

Carole Bryant (Naturopath),

Carole,
Thanks for the info. on silica.  I did not even think of sand as being a source of anything :(  So I will have to do some reading.  I have been sprinkling it in the flights but it was more to keep the poop from sticking to the concrete...or the steel floor in one flight.  Aside from that quite a bit always gets blown in and they're down there pecking at it.  The breeding cages also wind up with sand in food and water in small amounts daily.  When I empty the water there is always a little grittiness to the bottom.  So nature has obviously been taking care of the birds needs :)

Today I spent a lot of time in and out of the back door which resulted in tracking in quite a bit of sand.  The house birds all have babies right now including a new hatch today...which in watching them they randomly picked at the sand.  I let a few of the parent birds that are in the dining room flight and they went foraging in the sand build-up.  They've been doing this for years with no ill effects to the babies or themselves...I just never thought about it before.

Another thing the house pets go nuts over is when I take out a tub of margarine or butter for toast for me...they attack the margarine/butter like vultures and shove each other out of the way.  Which got me to wondering what is in there?  Many tiel babies have been fed margarine (small amounts) from the parents, again with no ill effects.  The only thing that I could think that would generate this response is possibly
*lecithin* which I believe is used as the thickener/stabilizing agent. I think *choline,* which cockatiels tend to have a higher need for, is one of the active (??) ingredients of lecithin.  So that is on the *To Do* current study list....and sources such as saturated (animal-egg) or polyunsaturated (vegetable)  I do know that hardboiled eggs are looked at as a take it or leave it thing.  So I think I'll be looking at plant sources I can possibly grow that elicit such a response.

Susanne