using oyster shell grit but still getting soft eggs..UPDATE!

I have 3 hens, a buff orpington bantam, a silkie and a warrens. my orp and silkie are about 9 months and lay really good eggs but my warrens who is older than 18 months (but not sure how old exactly) either lays eggs with really thin shells, soft ones, tiny ones and the occassional bigger than normal one....in the last week i got a big one and the shell felt a bit like sandpaper(thin shell) 2 days later i got a tiny one which had broken in the nest box and today i got a soft one but it did have a little bit of hard shell there was also a little bit of blood on it. i'm wondering whether its just to do with her age or something else. i've had these hens since about may this year, they are my first. i feed them layers pellets throughout the day and mix in oyster shell grit with their feed as they dont touch it otherwise. i keep them in their run until their first feed is all gone otherwise they would leave that too in favour of whatever they can find in the garden! Thankyou.

Hi,
this is a copy of an email i sent someone else with this query recently - hope it's of some use:

There are loads of reasons a chicken lays soft eggs but it is It is highly likely that you bird is suffering from cage layer fatigue - so now heres a very quick pysiology lesson and do excuse my spelling:-

Calcuim is stored in a special bone called a medulery bone, a caged he can deplete the stores in this bone - hence cage layer fatigue, sever cases can lead to the bird being unable to stand and will ultimatley result in death.

Your hen is using all of her energies and stores to build herself back up and its a big shock to suddenly be in the big wide world, in a "normal bird" If you are giving oyster shell and using a forumlated feed then calcium deficiency in the diet is highly unlikely, however in a bird that has depleated reserves then extra calcium may be required and I certainly wouldn't advocate extra calcium in an otherwise normal bird on a healthy diet just because it lays a soft egg as there are lots of reasons for this to occur.

Now oyster grit is great for slow release of calcium but particle size affects calcium uptake so smaller particles are required for quicker up take - limestone flour is best for this (ground limestone) However calcium uptake by the bird on the other hand is a different matter and uptake cannot be increased by simply adding more calcium, phospohrus to calcium ratio are vital too much of either will prevent the absorption of the other - this is called a limiting factor - phosphorus is required in egg production too, Vitamin D is the facilitator in calcium uptake and an excess of itamin can cause too much calcium to be taken in and therfore not enough has the opposite effect

For a short period of time add limestone flour to the mash, feed spinach and green cabages for the iron and folic acid (your bird is proably anemic too if it has cage layer fatigue - what is the colour of her comb?) My ex batts also get marmite on toast for a few days if they have cage layer fatigue (only a little bit though). do this for a week and see if there is any improvement in her general wellbieng, if there is then continue for another week maybe two before putting her onto a normal diet, if there is not then perhaps a vet trip may be required - also if her general health goes downhill at all then off to the vets. Do not be tempted to leave her on a high calcium diet for too long.

Apple cider vinegar is best if administered every or every other day - you may as well not give it at all if you are only giving it monthly - no offence. At this stage I would suggest worming and checking for lice, mites etc as all these put an extra load on an already overloaded system

For anyone else reading this that does not have an ex batt hen in this condition then do not be tempted to add excessive calcium to a diet - they should be getting enough and there could be another cause of soft eggs if it is just a one off. Feeding a hen on an increased calcium diet will kill it - put simply.

Thanks Roughlee...er where / how do I get the link?
Sorry, am I being daft??!

they do have layers pellets all day but i only let them out after i know for sure that they have eaten a dish full that way i know for sure they at least are getting some. during the rest of the day they have any veg that is going, brown bread (toasted) i've got them a bag of mixed corn treat made by feathers&beaky which i give a handful of in the afternoon then last thing at night i give them a handful of sweetcorn which i use to get them in their house. not sure if she's an ex batt as i got her from someone selling some of their stock..along with my other two hens. she's been wormed and had louse treatment as she did have lice at one point but not anymore other than that she seems a happy hen and the friendliest of the three.

i did wonder that, i was told she was a year or so when i got her and that was 4 months ago i thought if it was a diet thing then the other 2 would be the same. if she's not going to be laying is there another type of pellets i can get her rather than layers? thanks