Impact of dietary zinc and copper levels on ileal and total apparent nutrient digestibility in growing pigs

This study aimed to evaluate the effect of dietary zinc and copper levels on their apparent ileal digestibility (AID) and total tract digestibility (ATTD), and that of calcium, manganese, iron, phosphorus, and fibre in pigs. The experiment was carried out with six individuals fitted with a T-cannula. Pigs received one of four diets with two levels of zinc (100 [low] and 500 [high] mg/kg) and copper (40 [low] and 80 [high] mg/kg). HighZinc increased AID of zinc and manganese but decreased that of calcium (P < 0.05). HighCopper tended to improve AID of copper but only when highZinc was used (Zinc×Copper, P = 0.051). ATTD of zinc, copper, manganese, and phosphorus was greater in highZinc (P < 0.05). HighCopper also increased ATTD of copper, but reduced that of calcium (P < 0.05) as it likely did for ATTD of phosphorus in lowZinc (Zinc×Copper, P = 0.065). There was an improving trend for ATTD of NDF (Zinc×Copper, P = 0.069), and ATTD of ADF was increased with a combination of highZinc and highCopper (Interaction, Zinc×Copper P < 0.05). This research showed that levels of copper and zinc modified the digestibility of minerals but also the degradability of fibre.