Tannery by-product meal

Before hides are tanned, the flesh and epidermis are removed by either hand or machine scraping. The by-product from this process is usually used as fertilizer, but it can be solvent extracted, dried and ground to a meal for animal feeding. It is very rich in glycine (20.9%) and lysine (8.1%) and has been used to replace up to 25% of the soybean oil meal in poultry feed. It does not affect feed efficiency, but it tends to depress growth.