True Grit - To Feed or Not to Feed. That's the Question.
Crushed Oyster Shell Granite Grit Mix - Often sold in feed shops
Bring up the subject of grit with finch breeders and you might think you asked a question about religion or politics. I'm actually amazed at the number of times this subject comes up and the arguments for and against its use are often flawed.

Really, it boils down to details of husbandry. Whether to give grit or not, is not the only aspect of the equation. We know that birds in the wild naturally eat grit, but is this for the purpose of a mechanical action of digestion or for nutritional purposes? So, let's look at this objectively and then each keeper can decide on their own how it fits into their care routines.

The digestive tract of the finch has different parts than in the human digestive tract. We can see seeds being held in the crop, but this is not the stomach or gizzard. It is simply a holding area for seeds to wait until the stomach is ready to take on more food. The high metabolism of the bird requires that food constantly be available and far more than just the stomach and gizzard can hold. So the crop is just a way to gather and hold more food than is needed at the time. No digestion is taking place. The seeds then pass to the stomach or gizzard. On the way to the gizzard, acid is secreted to aid in digestion and then in the gizzard there are keratin plates that grind the seeds. This is where grit would be held and in some birds it is believed that the addition of hard stones aid the gizzard and its keratin plates in grinding food.

It has been shown that the keratin plates themselves are sufficient to mechanically grind or further manipulate the acid/food combination for digestion/absorption through the remainder of the digestive tract. So is grit necessary and why do birds eat it? Does the grit have any mechanical benefits of grinding the food? It probably does add something to the process of grinding, but most believe that in processing the food for absorption, the gizzard could accomplish this task without grit. However, this does not mean that the mechanical process is the only reason to ingest these grit items. As they are manipulated in the gizzard, the grit is worn down and then passed through the digestive tract. Various minerals that are included in the grit are then made available to the lower digestive tract for absorption. So grit really acts as a nutritional supplement and not as a digestive aid.

Can you get by without feeding grit? It depends upon your other husbandry routines and supplements. Are you feeding a diet complete with supplements that meets all the needs of your birds? If so, then perhaps their health is unaffected by the lack of grit in their diet. Grit should simply be viewed as a nutritional supplement.

Grit only ever becomes a problem in the gizzard of a bird that has some underlying gizzard disease or maldigestion syndrome. It appears instinctive for birds with digestive system malfunction to 'over eat' grit. Many people then blame the grit for the problem, but we need to consider what is the underlying process in these situations and treat that, not simply remove the grit. Diseases and parasites like Candida, Avian Gastric Yeast, Gizzard Worm and even Diarrhoea can stimulate the natural instinct of birds to eat grit. When it is found 'impacted' in the gizzard it is not really impacted because it could pass through, the bird has simply started eating excessive grit because of the GI tract disease.

What is defined as "grit" can also vary depending upon whom you talk to. Some think of it as only as bits of granite-like stone, while others only offer softer items like oyster shell. I personally have a mix of finely ground oyster shell, a touch of charcoal, some sea salt, bits and pieces of cuttlebone that are no longer on the bone and some egg shells. I used to offer a more stone-like grit in addition to the other items, but no longer include it in the mix.

So arguing over the use of grit is like arguing about whether or not one should use vitamins in water or not. Some people do, some don't, but the issue is not that cut and dry. An overall look at the birds diet and intake along with other husbandry routines are in order to come up with a complete picture and a decision of whether the procedure is "right" and beneficial for your birds.

Mineral Supplements:
For my birds I offer two different grit items. The first is easy to recognize. Crushed egg shell. I take the egg shells that are left after I produce my Egg Food and then microwave it for several minutes until thoroughly dry. I then just crumble it in my hand.

The second grit item I offer is a mixture of items, but basically it is oyster shell, sea salt, bits of cuttle bone and some charcoal. I grind my oyster shell in a old coffee grinder. The oyster shell is purchased from a feed store, but the size is more appropriate for chickens. I then add some sea salt (table shaker size), scrape the remaining bits of soft cuttle bone from broken bits or those unfinished bones that were hanging in the cage and lastly some charcoal. I bought a small can of this stuff and it lasts for quite some time. Some birds eat more of this than others, but all birds take in some. All grit is offered in separate containers and you should try to keep the mixture dry.