How to maintain egg production using permaculture based methods and non-grain feeds?

My boyfriend has been raising chickens to sell eggs for almost 3 years. We have between 130 - 175 dozen eggs a week going out, depending on the season. He is very concerned about maintaining production as we do home deliveries and sell out of eggs almost every week and customers aren't happy if they can't get their eggs when they want them. I want to start incorporating more permaculture concepts and reduce our need for grain-based feed, but he is concerned that if they aren't getting a regulated protein percentage, egg production will suffer. Ok, well my goal for the place is to maintain all of the chickens off of only what we grow on our land and cut feed costs to next to nothing.

At this point we have somewhere close to 1000 birds from newly hatched chicks up to broilers and laying hens. We are constantly incubating & hatching our own eggs to cover the birds aging out plus additional to grow the flock. The birds are free range - we open the barn doors in the morning and they have run of our 150+ acre property - although they hardly venture that far. During the summer they feed largely on what they forage, but during Colorado winters, we have to provide all of their feed. We do grow fodder and are partnering with a local juice place to get their leftover pulp (keeps it out of the landfill and our chickens LOVE it!) so they do get some greens, but not enough to make a dent in what we need for grains.

Does anyone have any experience or recommendation for resources on how to maintain egg production in a permaculture environment with this many birds? We live on the high plains where it's flat, windy, altitude of 6500 ft and very little plant life growing on the property with the only trees right around the house (the guy who owned the property before us chopped everything down and overgrazed it with cattle and horses until it was all almost bare ground ). So we pretty much have a blank slate to work with as far as what we can do with the property. I am trying to plan things over the winter so I know what we are going to do once the ground thaws in the spring. Any advice or recommendations greatly appreciated. Thanks!

We produce soap, getting the tallow from a local butcher as scraps. We render the lard/tallow ourselves, and feed the cracklins to the chickens which significantly ups their protein. We have also simply fed them the raw scraps, sometimes grinding it first. They LOVE that.

Modern chickens have been bred (for quite a while) to produce vastly more eggs than they would in a "natural" setting, which is accomplished in large part by feeding them large quantities of grain and a rather particular amount of protein.  So it strikes me that you can't have your cake and eat it too--you can't have your chickens subsisting on forage and lay like they've got troughs full of grain in front of them.

It seems the question is, do you want to maintain a high (unnatural) level of production or do you want to optimize your profit percentage?  If the former, keep at it.  If the latter, be happy with fewer eggs that still bring the same net profits, or raise significantly more birds to offset the lower production and to keep your current customers happy.