How to fatten up chickens to eat? My tia came over and was ready to kill 2 for my mom but she said they were too skinny. What should I feed at a cost effective range to them.. They are delawares around 12 weeks old.... I got 5 of them as chicks hoping to breed them for more delawares but came out with 5 roosters. But just in general if they are too young another question is what would be the cheaper and better way to feed them 18% protein chick grow or pure cracked corn(which is the cheaper) for a few weeks?