If you raise poultry as a hobby, or on a small-scale, it’s typically not feasible to mix your own feed. Larger-scale commercial operations maintain the ability to purchase bulk amounts of the individual ingredients, plus have the equipment to grind, mix, and pellet their feed. Buying an already formulated feed from a dealer means it’s important to consider what types of feeds are recommended for each type of poultry, and why.
The feed label will have instructions on how best to use the feed. Broilers:
This identifies chickens that are being grown to harvest their meat. Modern strains have a hearty appetite and grow quite quickly. A day-old chick will quadruple its weight in just the first week of life. This is why Broiler Starter diets need a high level of protein, as well as higher calcium and phosphorous for proper body development. As the birds age, they can be switched to a Broiler Finisher diet. Since the birds are larger at this point, and will be growing at a slower rate, this diet will have more calories with less of the other nutrients (protein, calcium, etc.).
This identifies chickens that are actively producing eggs to eat. Many people begin raising their own poultry by keeping a few hens as a source of eggs. Egg-laying breeds do not grow at the rate of broilers, so they will need less protein and energy. The biggest difference in the needs of the layers is the amount of calcium needed to form egg shells every day. The diet should contain 3-4% calcium, and should only be fed to birds that are laying. If a layer diet is fed to a young, developing hen (pullet), it can result in bone problems or they may even die from kidney failure. A pullet that is between 1-18 weeks of age should be fed a diet formulated for pullets, which will have less protein and energy than a Broiler Starter diet would but will not have the high calcium levels of a layer feed.
Scratch grains are not something that should be fed as the sole source of feed to any poultry type. The grains in scratch feed are high in calories and are a much lower source of the key nutrients (protein, vitamins, minerals) than formulated feeds.
While chickens certainly enjoy scratching and pecking the ground for food, their digestive system is not like that of ruminants such as cows or goats. They are not able to get much nutrition out of grasses and other high fiber plants. And though they may be able to find a few bugs as a source of protein, scavenging for food is something that should supplement continual access to a formulated feed best suited for them.