What type of stone/insoluble grit, when you can't buy it?

[porokelle]

Hi all,
We're in New Zealand, and while we can easily buy oyster shell grit for calcium, insoluble granite grit is not for sale.
Our girls free range, but that also means they've eat grass and weed heavy meals. And I don't know that the ground has enough of the types of stones they need.
We live on the coast so I can go to the rivers and estuaries to collect stones, but I want to make sure it's okay to give them extra small stones (after they've been washed of course), despite not knowing their composition?
I do live in a granite mountain area, but doubt the river rocks will be granite.
Does anyone else go collecting and give their flock small stones, rather than buy them from the store?
Thanks!

 

[RoosterRambler]

Hi there!

I understand your concern about not being able to find insoluble granite grit for your chickens. Collecting small stones from rivers and estuaries can be a great alternative, but it's important to make sure that they are safe for your chickens to consume.

If you're unsure of the composition of the stones you've collected, it's best to err on the side of caution and not give them to your chickens. You could try contacting a local geologist or rock collector to help you identify the stones you've found.

Another option is to provide your chickens with other sources of insoluble grit, such as crushed eggshells or finely crushed clean sea shells. These can provide the necessary grit for your chickens' digestion.

Good luck!

 

[Sussex19]

Are there any granite boulders where you are?
Here, if you go to the base of one, there is always a nice heap of bits that have fallen off.
My concern with river stones is that they will have been smoothed by the water and won't have any of the sharp edges needed for grinding.

 

[Sussex19]

insoluble grit, such as crushed eggshells or finely crushed clean sea shells

These are soluble, not insoluble, I would have thought?

 

[Ridgerunner]

My concern with river stones is that they will have been smoothed by the water and won't have any of the sharp edges needed for grinding.

You don't need to worry about that. I open the gizzard when I butcher chickens. The stones I find in there may have started off sharp and angular but they are soon ground smooth. Are you familiar with a mortar and pestle for grinding spices, grains, and other things. Those are not sharp and angular yet they grind really well.

And I don't know that the ground has enough of the types of stones they need.

For thousands of years chickens have been finding insoluble grit for grinding in their gizzard without help from humans. They can use practically any gravel they find. The harder it is the longer it lasts. Tere are some places where they may not be able to find gravel, peat bogs and maybe a swamp muck come to mind. As rocky as New Zealand is I have trouble envisioning them having any problems finding grit.

If you want to collect gravel for them go for it. They need gravel the size of a green pea or smaller.