313 Effect of Dietary Trace Mineral Source on Performance, Bones Mineralization and Mineral Status in Fattening Pigs

Abstract

Abstract Several papers report greater bioavailability of dietary trace mineral fed as organic in pigs compared with inorganic sources. However, only a few studies have tried to assess the variability of the trace mineral bioavailability among different organic sources. Growing barrows (n = 54; initial BW = 28.9 ± 1.3 kg) were used to determine the effects of trace mineral source on growth performance, bones mineralization and mineral status over the entire fattening period (d0-d73). Pigs were blocked by BW and randomly assigned to supplementation of trace minerals as inorganic (ITM) or one of 2 organic sources (OTM): glycine complex (GLY) or amino acids complex (AA). During the two feeding phases (growing: d0-d35; finishing: d35-d73), the experimental diets were supplemented with 5, 35 and 5 mg/kg of Cu, Zn and Mn, respectively. Pigs were fed restricted all through the experimental period. Feed intake was therefore comparable all through the experimental period for all pigs. Growth performance did not differ among the three experimental groups during the growing phase. However, Feed:Gain ratio measured during the finishing period tended to be affected by the dietary treatments (P=0.10). When grouping the GLY and AA pigs, the Feed:Gain ratio measured from d35 to d73 for the OTM pigs was significantly lower compared with ITM pigs (-0.07, P = 0.03). There was no significant effect of the dietary treatment on plasma trace mineral concentrations and alkaline phosphatase activity measured at day 34. At the end of the growing phase, plasma ceruloplasmin activity tended to be greater for the GLY and AA groups in comparison with the ITM pigs (+6.9%, P = 0.06). The zinc deposition in the proximal phalanx was significantly increased when the trace minerals were offered as organic compared with the group ITM (+10.9%, P = 0.06). Zinc content in the liver was greater for the pigs fed the OTM sources compared with the others (+6.0%, P = 0.10). The quantity of copper deposited in the liver did not differ significantly among the 3 trace mineral sources. This study indicates that the total replacement of inorganic Zn, Cu and Mn by organic sources brings benefits in terms of feed efficiency in fattening pigs. A better bioavailability as suggested by greater deposition levels in bone and liver as well as the increased circulating ceruloplasmin activity could explain the improvement of performance during the finishing period. Regardless of the variable considered, no significant differences were noticed between the two organic trace mineral sources.