Impact of zinc and arginine on antioxidant status of weanling piglets raised under commercial conditions

摘要

The effects of dietary zinc and L-arginine supplements on the weight gain, feed efficiency, antioxidant capacity and oxidative status of weanling piglets raised under commercial conditions were examined. A total of 288 piglets aged 21?d were fed for 15?d a diet supplemented or not with 2,500?mg/kg of zinc (provided as zinc oxide) and 1% L-arginine·HCl. The 4 treatments were distributed in a randomized complete block design with 6 initial body weight categories (12 animals per pen). Access to feed and water was ad libitum . Data were analyzed as a 2?×?2 factorial experiment using the SAS MIXED procedure, with zinc and arginine as the main independent variables. Blood collection day (d 8 and 15, samples were collected from the same 2 piglets in each pen before the morning feeding) was included as a third factor. The zinc supplement increased the average daily gain (ADG) from d 0 to 7, d 8 to 15 and d 0 to 15 (0.289 vs. 0.217?kg/d), average daily feed intake (ADFI) from d 8 to 15 and d 0 to 15 (0.338 vs. 0.279?kg/d) and the gain to feed (G:F) ratio from d 0 to 7 and d 0 to 15 (0.86 vs. 0.77) ( P ??0.001). Both supplements significantly decreased the malondialdehyde concentration (zinc: 4.37 vs. 3.91?μmol/L, P ?=?0.005; arginine: 4.38 vs. 3.89?μmol/L, P ?=?0.002). Total antioxidant capacity and reduced glutathione (GSH) increased from d 8 to 15 (0.953 vs. 1.391?μmol/L, 2.22 vs. 3.37?μmol/L, P ??0.05) regardless of dietary treatment. Total and oxidized GSH concentrations on d 8 were higher in response to the combined supplements (zinc?×?arginine interaction, P ??0.05). Piglets fed either Zn-supplemented diet had a lower haptoglobin serum concentration (509 vs. 1,417?mg/L; P ??0.001). In conclusion, the zinc supplement improved piglet growth performance (ADG and ADFI) and oxidative status (based on malondialdehyde concentration). The arginine supplement had a limited effect on growth performance and oxidative status under these conditions.