Animal feeds gain value depending on the concentration of nutrients in them. Feed containing high digestible nutrients per unit weight is called intensive feeds. Forages that contain low digestible nutrients by weight are called roughages. Foods rich in nutrients are also rich in dry matter content. However, dry matter feeds that are rich in content may not always be intensive feed. For example, straw is rich in dry matter but is not easily digestible and is considered roughage.

ADL (Acid Detergent Lignin), which is used to determine the digestibility and net energy value of feed, means lignin which is insoluble in acid detergent solutions. The acid detergent lignin (ADL) assay is the process of calculating the amount of lignin, one of the plant cell wall compounds, in the feed sample. Lignin is present in the cell wall of plants and together with cellulose provides the woody structure and durability of the plant.

Lignin is found in grass and grass in different proportions. The biological function of lignin in living plants is to produce a tissue on the cell wall that has excellent strength and resistance with cellulose and other carbohydrates.

Acid detergent fiber (ADF) is the strength digestible or non-digestible portion of the fiber, such as lignin and cellulose. If the ADF ratio is low, the feed is easily digestible. These are high quality feeds.

In order to determine the amount of raw nutrients and metabolizable energy levels of roughages, raw cellulose, ADL and ADF ratios of these feed ingredients are utilized.

In authorized laboratories, ADL (Acid Detergent Lignin) determination studies are carried out within the scope of chemical tests and standards and test methods published by national and international organizations are followed in these studies.