I’ve fed mine Purina and Nutrena products and have been happy with the results. It’s probably slightly higher quality than Dumor and might improve the taste a bit.
But my absolute favorite feed that I’ve found so far is made by Poulin Grain and since I notice you are in Massachusetts, you might be able to get it here!
I feed the Egg Production Plus feed which is 18% protein instead of 16%, soy free (which I don’t really care about much but is an added bonus to me), and I think they add marigold and stuff to it. The color and taste is great on it. I get it at my local Agway but I’m sure it’s at other stores. I’m on the south shore.
But if you can’t get that one, Nutrena actually makes a similar feed called Hearty Hen that I’ve gotten at
TSC before.
But you’ll need to check the mill date on the bag because it doesn’t always sell fast and definitely not as fast as Purina. Ideally you’re looking for not older than 8 weeks but slightly older is probably fine. But sometimes
TSC food is really old lol
But actually, speaking of that, you should be checking the mill dates on all the food you buy. If it’s old, the nutrients degrade fast and that could be part of the problem.
Also I would limit treats to no more than 10% of the diet. It can water down the nutrition in the feed.
That said, free ranging always helps my eggs taste way better and the birds seem to really enjoy it if you are able to do that. If not, you can perhaps gather up some leaves/dirt/weeds or kitchen scraps and stuff for them to pick through.
Anyway, I would switch to Purina or Nutrena if you are able to. They are big, established companies and make quality feeds. Purina also adds some extra stuff to their feed to improve yolk color and taste so that may help.
But I’ve found my best eggs to be with either the Poulin Grain or the Nutrena Hearty Hen.
Also make sure they have oyster shell and grit available free choice on the side in separate containers.