By-products are defined as the non-food products produced during the processing of food crops, livestock, or aquaculture. These by-products can be used as feed ingredients in poultry operations, and can help to reduce feed costs while still providing necessary nutrients for the birds.

There are several types of by-products that can be used as feed ingredients in poultry operations, including cereal by-products, oilseed by-products, and animal by-products.

Cereal by-products are the residuals left over after the milling of grains like wheat, corn, and rice. These by-products can be rich in nutrients like protein, fiber, and energy, and can be used as feed ingredients for poultry. Examples of cereal by-products include wheat bran, corn gluten feed, and rice bran.

Oilseed by-products are the residuals left over after the extraction of oil from seeds like soybeans, sunflower seeds, and canola. These by-products can be high in protein and energy, and can be used as feed ingredients for poultry. Examples of oilseed by-products include soybean meal, sunflower meal, and canola meal.

Animal by-products are the residuals left over from the processing of animals for meat or other products. These by-products can be rich in protein and other nutrients, and can be used as feed ingredients for poultry. Examples of animal by-products include meat and bone meal, poultry by-product meal, and fishmeal.

In addition to being cost-effective, using by-products as feed ingredients can also have environmental benefits. Using by-products as feed reduces the amount of waste produced during food processing, and can help to reduce the demand for traditional feed ingredients like corn and soybeans, which can be resource-intensive to produce.

There are a few considerations to keep in mind when using by-products as feed ingredients in poultry operations. One is the nutrient composition of the by-product, as some by-products may be lacking in certain nutrients and may need to be supplemented. It's also important to properly store and handle by-products to prevent spoilage or contamination.

In conclusion, by-products can be an effective and cost-saving option as feed ingredients in poultry operations. By properly utilizing these by-products, poultry producers can reduce feed costs and minimize waste, while still providing the necessary nutrients for their birds.