Organic pricey veggies. Recommended by old timer for extra iron and other vitamins and minerals.
It's still a rather large amount for the number of birds. Your chicken feed has all the vitamins and minerals you need for healthy birds. As an occasional treat it's fine but large amounts of anything besides their feed is going to start throwing the balanced nutrition ratio of the feed off.
I doubt it's what's causing the lack of eggs (really think it's the heat) but something to think about. Maybe try cutting it out/greatly reducing the amount for a few weeks and see if there's any difference?