Need more info. Does the chickens get to free range? Are we talking feed only? Both? My 21 chickens free range most of the time and I put the layers out in the evening only (after they go to roost). They will go through approx. 1 full coffee can of crumbles. Does that help?
I have 13 hens, 2 roos, and last spring/summer they went through a 50 lb bag every eight to ten days. That's the layer ration, which I started in August, after they began laying (at four months of age!!!)
Over the winter, I fed more protein in the form of oatmeal, scrambled eggs, black oil sunflower seeds, and they ate much less layer ration. Now the weather is warming up, I'm cutting back a bit on the extras, and they're eating more chicken food again. But if you divide 50 lbs of food by ten days, that's five pounds a day, divided by 15 birds, that's about 3/10 of a pound of food per day per hen. If my math is right, which I don't guarantee.
I also feed lots of garden produce all summer, and when we mow the lawn, the birds get a bag of grass clippings (I don't dare free range - too many predators). So my girls might eat less than a bird who gets only chicken feed, but it should give you some idea, anyway.
BTW, I have gold sex-links, so they're not a real big, heavy bird, which of course would eat more. Hope this helps!
I have 6 Rhode Island red hens. They get free access to layer pellets, roam the yard & pasture when they can be supervised ( a few hours each afternoon for now, all day during the summer and weekends), and get a couple of handfuls of greens each day. If it is particularly cold or they seem bored I will throw a handful of grain for them to scratch at.
A 50 pound sack of layer pellets usually lasts more than a month, maybe 5-6 weeks depending on how much other stuff they get and how much time they can roam free.
I pick up a large carton of castoff greens once per week from my local organic grocery. If I can't get greens or the weather / schedule prevents roaming for a few days, then I give them a rehydrated alfalfa horse cube instead. And I split a 50 pound sack of scratch or other whole grain mix with another chicken neighbor. The 25 pounds of grain lasts the whole winter.
The commercial outfits make their profit by having a bird that eats 110 grams of feed and produces a 60 gram egg, each day. 110 grams is about 1/4 pound
If a 4 pound Leghorn eats 110 grams a day, it seems only right that an 8 pound Barred Rock should be allowed 220 grams of food each day. But, the BR won't eat twice as much as a Leghorn. (She's not going to lay an egg that weighs 120 grams, either.)
i'm planning for 7, and maybe they would be heavier
they would have a coop and a pen about 8x8 ft, and i could probably get "castoff greens" from any different grocery store...layer crumbles at my TSC cost $14.34CAD (about 12.60 American i think).
also if i do decide to clip the ends of their wings, i could possibly let them out in the yard a few times a week when my cats are inside and there are at least 2 people there.
BTW, i am asking this question because i am trying to get my older sister to buy one of the 7 and she doesn't know if she does because she wants one but she doesn't want to pay for it if it is too much.
Last year, I paid the $2/chick at the feed store and then $6 on feed to get the first pullet to point of lay at 21 weeks.
The laziest one out of the bunch cost me the same $2 but her share in the feed bill was nearly $9 by the time she kicked in with her share of rent & living expenses
at 26 weeks. (They eat quite a bit more between 21 & 25 weeks than they did when they were little ones.)
After these expenses, the laying pullets have been kept (not religiously, but close) to 1/4 pound of commercial feed each day. The way I do that is by weighing the feeder when it is refilled each afternoon. If they've eaten more than 1/4 pound each, they get lots of goodies from the kitchen. I also count scratch with these goodies/treats.
If they haven't averaged 1/4 pound each for the day, they don't get treats that evening. It is kind of equivalent to your mom saying "if you clean your plate, you can have dessert." But, dessert can be all sorts of things like veggies and such. In fact, they are out every day getting their own dessert in the yard. But for the most part, that 1/4 pound of commercial feed is what they are living on.
Oh, and they are pullets of large breeds. Yeah, they've always "cleaned their plates" by evening
. Hope this helps.
edited to say: Your bags are probably 25 kg. That's 25,000 grams. A 1/4 pound is less than 120 grams but let's say 125 grams. So, you've got 200 "chicken days" in each bag, if you feed like I do. I'll let you figure out how much each chicken is costing you for each day, from there.