I've seen it many times, and one of the situations is well taken care of, and one of the hens seems to have suddenly died of illness. I now know the questions to be asked. Is she laying thin shell eggs? Does she feel ill while lying down? Does she look weak but still hungry? Finally, do you want to feed crushed or mixed grains instead of grains? Is it organic?
Egg-laying chickens require specific levels of protein and minerals to produce these eggs day in and day out. They don't have too many reserves. To make shells, she must first take calcium from her feed, store it in bones, and then extract it from those bones. Egg whites are almost pure protein, so she needs to eat it steadily and then excrete it as an egg. But too much protein in the diet can lead to kidney disease.
Clearly, high-quality feed is essential. I understand why many people are turning to non-GMO, soybean-free organic feed. It promises the best ingredients. The nutritional information on the label is exactly what your hen needs. However, most of these professional brands do not appear in grainy form, but in the form of debris or mixtures, each of which looks different. Chickens are predators. They don't like the source of protein in this feed. They threw it on the ground and ate something else. As time goes on, they become thinner. It becomes difficult for hens to lay eggs. There may be internal breakage or infection. This will kill your hen. But hurry up and switch to granular feed, and the hens consume everything they should eat, so you can reverse the downward trend and reduce mortality. I've seen this reversal go back to health time and time again. Pellets are not necessarily highly processed products that you may be concerned about.
That's why I advocate commercial granules for backyard flocks. Hens can only maintain an egg-laying season before harvesting to control the non-optimal diet. But our beloved adult hen herd needs to balance and concentrate the ingredients in the pellets. That's not to say they can have it all. I also believe in providing nutritious food that allows them to graze and forage freely. But that's dessert. Make sure they have a nutritious main meal first.