One thing I notice is how dark it is in the coop. I would get out a saw and make a bunch of big windows. Lighting is very important for ovulation.
While it is true that heat stress can slow egg laying and for most breeds, I like foot baths.
What really stood out to me is that at a time of the year when production should be at the highest for a flock of hens, the first post said that egg size was getting smaller over time and number of eggs were continually declining.
In order to help reverse this trend, I need to know exactly what the hens eat every day. I need to know the crude protein percentage of the feed and anything else fed, whether it be scratch, treats or whatever. How much of the total intake is that chicken feed?
Adequate crude protein and especially attention to essential amino acids are necessary for acceptable ovulation rates. The lower the protein, the smaller the yolks. The smaller the yolks, the smaller the eggs.
Insufficient protein can prevent ovulation completely.
I was at a local feed mill and a guy in there wanted to buy some of my hens. I asked him why. He said his hens were broken. They were under two years of age but had stopped laying completely. I asked him what he was feeding. He said, "corn". I said, "what else?" He said, "just corn". I said, "you're starving them". I told him to buy a proper chicken feed, stop the corn completely. Within 3 weeks his birds had all resumed laying.