welcome to BYC SLIM0912! WOW, 300 broiler chicks is a huge undertaking! I grow out batches of 37 every 6 months for my family of 4, my next batch arrives March 1st and will be in the freezer by the end of April. my chicks go through about 16 lbs of broiler feed each during an 8 week grow out. your are looking at going through something like 4,800 lbs of food and producing literally several tons of droppings and about 2,000 lbs of meat. dealing with the droppings is the biggest challenge IMHO. you will find that there are varying practices on feed and rationing with the idea of keeping them from having leg and heart issues. however, it is my opinion, and not to step on any toes, that rationing is not the answer. with CX you are looking at the most efficient converter of feed to meat of any form of livestock, they are incredible but the rate at which they grow posses challenges.
they have something like 10X the metabolism of a heritage breed chicken. Oddly enough, by using a mother heating pad brooder (search MHP or mother heating pad) I stumbled upon what turns out to be one of the main determining factors in health for these birds, it's having at least 4 hours within a 24 hour period of true darkness. studies have found that chickens who get at least 4 hours of real deep sleep each night have greatly reduced leg and heart issues. darkness forces them to stay put and not move around and constantly bump into each other, thus giving them solid sleep for their bones and joints and internal organs to develop normally. I was noticing this when I stopped using a heat lamp in the brooder but then came upon actual scientific research in the book The Behavioral Biology of Chickens. largish scale production batches have been brought up with a dark photo period of at least 4 hours a night and shown dramatic improvements in health all around. I now give my CX 24/7 access to feed with a normal day and night cycle, using a heat pad and a light on a timer that turns off for about 8 hours a night. I have close to 100% liveability with virtually 0% issues. I do find that it helps to go with the COBB 500 strain, which I find is more active and healthy in general.
as for the food type, I'm not sure what alternatives you have available to you to come up with 2.5 tons of feed that is not commercially bought. since procuring that much feed requires buying in bulk, it's hard to imagine not buying closer to wholesale and in that case, it's hard to imagine beating the price of broiler feed. to come up with an alternative, you need to get really good at understanding how to estimate protein count and ways to adjust it slightly depending on dropping consistency, high protein = fast growth and good ROI, too much protein results in the squirts. I don't feel that it's humane to hold back food from these birds, they live to eat and get distressed without having free access to feed. So, I suppose if you have access to the raw materials and can grind the grain economically, that you could make your own grower formula and "save" some money. If you have a lot of acreage and can make enough chicken tractors, I suppose you could try and grow them out with supplementing the feed with grass and all the goodies that come with grass access, but this would take some experimenting and I'd recommend doing that with smaller batches first. For me, my only requirement that I put on myself is to beat the price I can get organic chicken at the store per lb, which I do and to provide a higher quality of life than it typical of a large scale operation, which I do. I process the birds myself and feel good about how humane my practices are and the quality of life that my chickens lead, albeit a short life. they live fast and die young. they are amazing creatures in their own right and working with them can be very rewarding.
you are going to need a commercial grade/scale processing system to harvest this many birds. I would not focus on making a profit the first time or two through this but instead work on nailing down the grow out process. once you get the hang of it, you can figure out ways to scale up and economize and hopefully make a profit. good luck with your venture.
