Dry and wet diets with and without phytase for growing and finishing pigs

The present study assessed the effect of adding water and phytase to middling diets on digestibility, metabolism, performance, carcass characteristics, and the bone mineralization of growing and finishing pigs. For the digestibility trial, 16 pigs were distributed in randomized blocks, placed in digestibility cages following a 2 x 2 factorial design (dry and wet diets, with and without phytase). For the performance trial, 48 piglets were distributed into a complete randomized design. During the growing period, wet diets presented higher values for digestibility and energy metabolism. In the finishing stage, the addition of water to the feed caused a greater weight gain and interfered with the carcass length. The balance of the mineral matter and the availability of calcium and phosphorus were influenced by the diets with phytase. The addition of water to the diets in the growing phase improved the digestibility and energy metabolism, and increased the weight gain, carcass length and calcium content in bones during the finishing period. The supplementation of phytase improved energy metabolism and the digestibility of calcium and phosphorus, and the balance of mineral matter.