Effect of sulfate or hydroxychloride sources and levels of copper, manganese, and zinc on growth performance, carcass characteristics, and body weight variation of finishing pigs

Abstract Two experiments were conducted to evaluate the effect of source and levels of Cu, Mn, and Zn on the performance, carcass characteristics, and body weight (BW) variability of finishing pigs. Experiment 1 used 2,025 pigs (337 × 1050, PIC; initially 39.9 ± 1.22 kg) with 27 pigs per pen and 15 pens per treatment. Treatments consisted of a control diet containing 30 mg/kg of Mn from MnSO4 (Eurochem, Veracruz, Mexico) or 15, 30, 45, or 65 mg/kg of Mn from Mn hydroxychloride (IBM; IntelliBond M, Selko, USA, LLC, Indianapolis, IN). From d 0 to 43, gain: feed ratio (G: F) increased (quadratic, P = 0.035) when Mn hydroxychloride increased up to 45 mg/kg but then decreased thereafter. There was no evidence for difference from increasing Mn hydroxychloride for any growth response in the overall period. When comparing Mn sources at 30 mg/kg of added Mn, there was no evidence of differences in any period or overall growth performance or carcass characteristics. In Exp.2, 1,026 pigs (337 × 1050, PIC; initially 25.9 ± 0.33 kg) were used with 27 pigs per pen and 19 pens per treatment. Treatments consisted of a control diet containing 110, 16, and 150 mg/kg of added Zn, Mn, and Cu, respectively, from sulfate sources or the same concentrations provided by hydroxychloride sources (IntelliBond, Selko USA, LLC, Indianapolis, IN). From d 0 to 61, there was a tendency (P = 0.052) for increased G: F when sulfate sources of Cu, Mn, and Zn were fed. From d 61 to 124, pigs fed hydroxychloride mineral sources increased (P = 0.041) ADG compared with those fed sulfate sources. However, there was no evidence for a difference in overall growth performance. A tendency (P = 0.054) for increased hot carcass weight (HCW) was observed in the final marketing event when pigs were fed hydroxychloride sources of Cu, MN, and Zn, but no evidence of differences was observed in the first marketing or when all marketing data was combined. In both experiments, pigs were individually weighed to calculate within-pen BW coefficient of variation (CV), with no differences observed in BW variability. In conclusion, feeding hydroxychloride sources of Cu, Mn, and Zn resulted in no differences in overall growth performance, HCW, carcass yield, loin depth, backfat, and lean percentage compared with feeding sulfate sources; however, the G: F improvement when Mn hydroxychloride was increased up to 45 mg/kg and the tendency to increase HCW when feeding Cu, Mn, and Zn hydroxychloride warrants further investigation.