This type of food is similar in appearance to dry dog food and is formed by processes that are very similar to pelleting. Feed mixes being forced under high pressure through the extruder cooker characterize extrusion cooking. The extruder is a large continuous flow pressure cooker, which utilizes high volumes of steam under extreme pressures and hot temperatures. The mix is then forced through a die, which determines the diameter and shape of the feed. After exiting the die, the nuggets will puff up due to sudden changes in temperature and pressure.
Some moisture is removed form the extruded feed by evaporation.
Hot dryers are also used to remove some moisture. Extruded feeds have advantages similar to pelleted feeds including less waste, and easy storage. The gelatinzation involved in extrusion cooking may increase the availability of carbohydrates and energy in the diet. Horses which may benefit from extruded feeds include horses which are prone to colic, or choking, horse which eat their feed to rapidly, and growing horses which are raised in group feeding situations. Message Forums .