Wanting to feed my flock with less manufactured/commercial feed..

I have read a few of the other threads on feeding and found them great but thought that to find answers to my own situation would be easier to start my own thread.
I currently feed my flock (60+ birds) on half pellets and half grains, wheat and maize(often boiled, or sprouted with yeast and molasses), brought direct from the growers. My birds sadly have to be kept in pens/tractors now as they get into everything and the dogs get into them! lol.But most of them have access to grass or picked greens daily. I also live on a dairy farm and with spring just around the corner they milk is coming in by the bucket! Yay. So they also get curds adlib, as much as they can eat! I also feed some seaweed meal and linseed meal.
I would like to cut out the pellets part for the older birds and also cut down the chick starter for the youger birds.

So to do so I thought they will need some fish/meat addition. We do get some meat bones and scraps that I boil up along with pumpkins and veges. But the dogs have first priority in that department so there is not alot lol!
So I have found a local supply of fresh fish waste/heads so I am wondering how much fish would they need?(as a percent of total ration), I plan on boiling them up. Since they do cost I would like to just feed the amount needed rather than too much un-necesasarily.

I also plan in growing extra pumpkin this year as well as sunflowers, that was an excellent sucsess this winter, they loved their whole boiled pumpkins to pick at all day in the colder weather. I am also going to try growing 'oil seed pumpkins' that have huskless seeds so they can eat the seeds too as an extra winter treat.

I really look forward to not having to buy 100's of kgs of pellets every 2nd week when I go to town!

 

-I feed the pumpkins as a treat to keep them busy and I find they only eat say 1, 2-3kg pumpkin between 20 or more growers over 2 days. They are never hungry enough to 'have' to eat it if they do not want so I assume they are only eating what is ok for them.
but what I would like to know is what is so wrong with pumpkins ? learn something new every day!

-The fish heads I got today, I just poached them enough that the meat came away so they could eat it easily. It was sooo interesting feeding it to them. I had about 1.5kgs and just went round the pens and shared it out. No one seems remotly interested in the bones either..The laying hens thought it was alright but only wanted a bit. The growers couldnt get enough of it! and one pen of a particular breed wouldnt go near it! they are the same breed I have found pretty much does not eat worms (I have never wittnessed it with my eyes!)! they are very weird lol.

That was very interesting reading! (pastured poultry nutrition)
I will be keeping the percent well below 5% to avoid fish flavour in the laying hens, but with some of my birds they are just for hatching so it is not a problem, also will be fed alot to the growers as I imagine they will benefit from it.