5 Very thin shells
Very thin shells that break easily can be due to a lack of balance of calcium, phosphorous and vitamin D in the diet. It is also a symptom of a couple of very common viral diseases, infectious bronchitis and egg drop syndrome. If thin shells are caused by a disease, you’ll also see others changes, like watery whites, paler shells, and less eggs.
A lot of people think the answer to thin shells is to feed more calcium in the form of crushed egg shell or oyster shell. However, excess calcium can also cause more shell problems, like excess calcium deposits and pimples on the surface of the egg.
To form an egg shell, a hen needs to have the calcium, phosphorous and vitamin D components of her diet in the right proportions. Nearly all commercial layer feeds are perfectly balanced, providing sufficient calcium for the bird’s everyday needs, plus phosphorous and vitamin D in the correct ratio.
The only time that extra calcium needs to be available is when you are running a high production flock, and/or a balanced commercial layer feed is only part of the flock’s diet. For example, if a commercial layer feed is only 50 per cent of a flock’s intake and you are feeding out large amounts of scraps or other grains, the birds can adjust their intake if extra calcium is offered. However, it’s vital any extra calcium is not mixed in with feed. It should always be offered in a separate dish so the hen can choose.
Generally, hens will choose to eat calcium supplements in the late afternoon when their blood calcium levels are lower as they withdraw it to make the next day’s egg shell overnight. Roosters and young nonlaying birds do not need extra calcium.
Do not give Layer feed to chicks or it will overload their immature kidneys with calcium crystals. This can cause irreversible damage, and often the bird may die from kidney failure months later when her body come under stress, for example if she gets run down by another illness.