196 Effects of zinc source and level in low ABC-4 diets on nursery pig growth performance and fecal dry matter

Abstract Incorporating pharmacological levels of Zn in nursery pig diets is a well-recognized practice for reducing post-weaning diarrhea, enhancing growth performance, and enhancing gut health. We hypnotized that the use of a specific form of ZnO (small aggregates and agglomerated particles; SAAP), which provides a greater antibacterial property than standard ZnO, could be added at reduced levels without compromising piglet performance. This study aimed to explore the effects of different levels of SAAP Zn source (HiZox, Animine, France) in low ABC-4 diets with low or high CP content. A total of 360 weanling barrows DNA 200 × 400, initial body weight (BW) = 5.9 ± 0.4 kg were used in a 38-d experiment. Pigs were randomly assigned to pens (5 pigs/pen) and pens assigned to 1 of 6 treatments with 12 pens/treatment. The experiment consisted of phase 1 from d 0 to 10, phase 2 from d 11 to 24, and phase 3 from d 25 to 38. Treatments consisted in a negative control (NC), which had 150 ppm of Zn (HiZox) throughout the experiment and the remaining treatments were: positive control (PC) containing 3,000 ppm (phase 1) and 2,000 ppm (phase 2) of Zn provided by ZnO; low-HiZox containing 500 ppm (phase 1) and 300 ppm (phase 2) of Zn; low-HiZox-low-CP was similar to low-HiZox but contained less CP (19.3%) than the NC, PC, low and high-HiZox diets (21.3%); high-HiZox containing 800 ppm (phase 1) and 500 ppm (phase 2) of Zn; and high-HiZox-low-CP was similar to high-HiZox but contained 19.3% CP. In phase 3, all pigs were fed a common diet containing 150 ppm of Zn (HiZox) and high CP. For the experimental period (d 0 to 24), average daily gain (ADG; quadratic, P = 0.007) and average daily feed intake (ADFI; quadratic, P = 0.018) increased as HiZox increased (Table). Pigs fed high-HiZox-low-CP had poorer gain to feed ratio (G:F; P 0.05) than NC, PC, low-HiZox, and high-HiZox. Additionally, in both experimental and overall periods, pigs fed diets with low CP had decreased G:F (P = 0.043) than those fed the same Zn levels but with high CP. Overall, pigs fed high-HiZox-low-CP had decreased G:F than pigs fed high-HiZox only (732 vs. 761 g/kg, respectively; P 0.05), with other treatments intermediate. For fecal dry matter (DM), pigs fed low CP diets had greater (P = 0.008) DM compared with pigs fed high CP. Thus, the inclusion of HiZox at 800 and 500 ppm in phases 1 and 2, respectively, in a low-ABC-4 diet might be a strategy to reduce the use of pharmacological levels of Zn from ZnO in nursery diets.