Why was your chickens egg deformed?

Answer 1

Your hen may be reaching the end of her productive egg laying years. This often happens at about 3 years old or sooner. The hens intake of vitamins and minerals is no longer well absorbed and more of her nutrition will be used for feather production and fattening up. The addition of extra calcium in the older hens diet may stall this inevitable ceasing of egg production but it does eventually end. The bird may go on to live a healthy life for years after.

If the bird is young still, between 6 months old and 30 months you might try adding a water soluble tonic to the water supply with extra minerals to boost shell formation. This is available at all co-op and feed stores.