Comparison of inorganic and organic trace mineral supplementation on the growth, performance and fecal mineral excretion in phase-fed, grow-finish swine

Crossbred pigs (EXP. 1, (n=528); EXP. 2, (n=560)) were utilized to compare the effect of trace mineral supplementation on performance and fecal mineral excretion of grow-finish pigs. Dietary treatments were allocated in a general randomized complete block design with 12 replicate pens per treatment (TRT) and 9-12 pigs per pen throughout the grow-finish period (18-118 kg BW). In EXP. 1, the control diet (TRT 1) contained Cu, Fe, and Zn from inorganic sources at concentrations of 85, 169, and 163 mg/kg, respectively. Treatment 2 (TRT 2) contained Cu, Fe, and Zn from organic sources at concentrations of 19, 131, and 91 mg/kg, respectively. Micromineral concentrations from TRT 2 were reduced by 25 and 50% for TRT 3 and TRT 4, respectively. In EXP. 2, TRT 5 contained 25% of the Cu, Fe, and Zn concentrations found in TRT 1. Treatments 6 and 7 (TRT 6, TRT 7) contained the experimental microminerals at concentrations that were reduced by 50% and 75% from the levels in TRT 2, respectively. Microminerals were removed from TRT 8. There were no differences in treatment means (P \u3e 0.05) for BF10, LMA, ADG, lean efficiency (LE), percent lean live, percent lean carcass, and kilograms of lean. Fecal concentrations of Fe and Zn were greater (P \u3c 0.01) for the first three phases and for the entire test period for pigs fed TRT 1 when compared to pigs fed the other dietary treatments. In EXP. 2, pigs fed TRT 8 had poorer (P \u3c 0.01) ADG, lean gain on test, and LE, and lower ADFI when compared to pigs fed the other dietary treatments. Additionally, no differences among treatment means for fecal Cu excretiun (P \u3e 0.05) were observed by phase, however, pigs fed TRT 8 excreted the lowest overall concentration of fecal Cu (P \u3c 0.05) when compared to pigs fed the other experimental diets. Pigs fed diets containing organic Cu, Fe, and Zn can achieve similar growth and carcass composition as those fed diets containing the inorganic mineral forms, however, excrete significantly less fecal mineral concentrations