Hens eating too much oyster shell/calcium?

[porokelle]

We're in the height of summer here in New Zealand. I've got 4 orpingtons and one game bantam. All are showing broody bare chests but haven't gone full brood.

And all of them are madly chowing down on the freely offered oyster grit.
I have one of those inverted wine bottle bird feeders that I fill with oyster shell, and they've gotten through the bottle in maybe 3-4 weeks, whereas normally it would take 3 months.

They are laying eggs daily, but they've been doing that since the beginning of spring. And two of the girls are starting to have daily calcium deposits on the eggs.
They are almost running for the oyster shell when they crave it.

Should I be worried?

Only other things I can think could be affecting them -
About 3 weeks ago they finally got over (fingers crossed) a virus/bacteria that took a good two months to work through the whole flock (tho I think one girl still has it).
We have a few cases of bumble foot (normal for our 8lb girls this time of year).
And I did switch out their food a month ago to a higher protein one because they were refusing their last bag (which may have just been bad and contributed to their illness).

They're free range with a good game feed. They get some treats (peanuts, sunflower seeds, pumpkin seeds) before bed. And all of them feel their normal weight around the keel (I'd like it a bit higher for all of them and a lot higher for the runt).

 

[cavemanrich]

I would not be too worried about them overindulging in the oyster shells. Whatever does not get used up, for eggshell interior production,,,, will pass thru the chickens' digestive track.
It is a possibility,, that the sickness they went thru may have changed their needs for calcium?? Very possibly, things will normalize after a FULL RECOVERY,,
Do you also offer egg shells from eggs you consume, for breakfast,,,, back to your chickens?? I do that regularly,,, and the cracked egg shells do get consumed. I also do offer Oyster shells free-choice.
In the past,, I did get extra calcium deposits from one of my hens, That was occasional, and did not last,,, or develop any harmful conditions.

WISHING YOU BEST,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

 

[porokelle]

I would not be too worried about them overindulging in the oyster shells. Whatever does not get used up, for eggshell interior production,,,, will pass thru the chickens' digestive track.
It is a possibility,, that the sickness they went thru may have changed their needs for calcium?? Very possibly, things will normalize after a FULL RECOVERY,,
Do you also offer egg shells from eggs you consume, for breakfast,,,, back to your chickens?? I do that regularly,,, and the cracked egg shells do get consumed. I also do offer Oyster shells free-choice.
In the past,, I did get extra calcium deposits from one of my hens, That was occasional, and did not last,,, or develop any harmful conditions.

WISHING YOU BEST,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

Thanks.

Is there a reason you offer egg shells? We offer oyster because I've read it lasts longer and is slow release as opposed to the egg shells. I have given them in the past if we have any thin shells along with a calcium pill.

We just ended up with one of the girls with calcium on her eggs showing signs of sour crop for the third time in three months, so yeah, maybe after full recovery whatever that looks like she won't have this issue.

 

[cavemanrich]

Egg shells are a recycling of calcium the natural way. I have been doing this with my flock for over 20+ years. Some people bake, and crush their egg shells. I just drop on ground in run area,, and step on with shoe to crush. Never a problem. Chickens find as they come across them.
Experiment; Take away the oyster shells for a few weeks, and just offer the egg shells. Then review your results.
Consider that calcium is also available in green vegetation growing in your yard ,,, where your chickens may be scratching free-range.

 

[Eggcessive]

What kind of a virus has been affecting some of your flock? Has there been any frequent sneezing? If so, that could be infectious bronchitis, a virus. IB virus can cause some changes in the shells, and can later be a cause of reproductive disorders. Have you seen any corrugated or wrinkled shells?

Shell gland problems in the oviduct can cause mineral deposits on shells, but there can be other reasons. Here is a good guide to egg shell problems with possible causes:
https://www.backyardchickens.com/articles/common-egg-quality-problems.65923/

 

[Stravager]

Might be a silly question, but are you offering them a source of grit aside from the oyster shell?

 

[porokelle]

What kind of a virus has been affecting some of your flock? Has there been any frequent sneezing? If so, that could be infectious bronchitis, a virus. IB virus can cause some changes in the shells, and can later be a cause of reproductive disorders. Have you seen any corrugated or wrinkled shells?

Shell gland problems in the oviduct can cause mineral deposits on shells, but there can be other reasons. Here is a good guide to egg shell problems with possible causes:
https://www.backyardchickens.com/articles/common-egg-quality-problems.65923/

We're not sure what virus it could be. We have 100's of wild birds in the area. And when we hit the height of summer here in New Zealand, everyone seemed to get broody and sick one by one. Three of them have definitely had sour crop, one after another (and one of them having it 3 x in a row over 2.5 months).

We've had a single shellless egg before one of the sour crops, another had some fluid in the abdomen. They're 8lb orpingtons and at least 3 have had bumbles in the past 3 months, despite being free range most of the day and having access to laying on towels in the coop at night along with the roost (we switch the towels out every day to keep it clean). And the runt (lowest on pecking order and is a picky eater) has had a single large bubble in her eye twice - but no other symptoms.

The girl with 3 sour crop infections is incredibly sensitive to heat and has previously had problems laying eggs unless she's cooled down, and then lays 2 within 12 hours. The second egg ends up being flat sided, as we suspect the 2 eggs bumped into one another in the canal. She's only done that once this year, but I'm sure her reproductive and heat issues are contributing to the sour crop issues.

We treated for worms about 2 weeks ago, just in case.

Upside - Everyone seems happy, pooping correctly, and laying pretty well other than the excess calcium (we have had more deformed shells this year, but just a bit misshapen/pointier at one end - not wrinkled or corrugated).
Main problem has been dealing with the giant sour crops.

 

[porokelle]

Might be a silly question, but are you offering them a source of grit aside from the oyster shell?

We haven't. I'm in New Zealand and they don't sell it here.
I could try going to the rivers, but I am afraid the small stones I find would be too large or not rounded enough. The girls are free range and do find stones.

 

[Stravager]

We haven't. I'm in New Zealand and they don't sell it here.
I could try going to the rivers, but I am afraid the small stones I find would be too large or not rounded enough. The girls are free range and do find stones.

Don't know what kind of stones you have out there but if you suspect they aren't finding enough something else you could check out is the gardening centers. Sometimes they carry very tiny pebbles for potting succulents.

 

[porokelle]

Don't know what kind of stones you have out there but if you suspect they aren't finding enough something else you could check out is the gardening centers. Sometimes they carry very tiny pebbles for potting succulents.

That's a really great idea. I'll check it out. I know they have vermiculite and pumice, but I bet they have small pebbles too.