Glossary of Terms acid detergent fiber : the portion of hay that is highly indigestible. The lower the ADF, the more feed an animal can digest. Thus, a low ADF is desirable. available protein : the amount of protein remaining for use by the animal after subtracting the indigestible protein such as heat damage protein. This calculation only occurs when the level detected is greater than the level normally expected in the plant. crude protein : a mixture of true protein and nonprotein nitrogen. Crude protein indicates the capacity of the feed to meet an animal's protein needs. digestable protein : the estimated amount of protein an animal can utilize. dr y matter : the percentage of the feed that is not water. Dry matter equals 100 percent minus percent water. ene/est-estimated net energy : ne/lact is net energy for lactation. ne/maint is net energy for maintenance. ne/gain is net energy for gain. These are calculated values used to balance rations. heat damage protein : a measure of protein bound up in the forage caused by improper storage. neutral detergent fiber (NDF) : the portion of hay that is only partially digestible and limits intake. The lower the NDF, the more an animal will eat. A low NDF is desirable. relative feed value (RFV) : a ratio calculated by combining the digestibility and potential intake of a forage into one number. RFV increases as forage quality increases. total digestible nutrients(TDN) : the digestible components of fiber, protein, fat and nitrogen-free extract in the diet.