PSI-5 Intestinal responses and the determination of true total tract trace mineral digestibility and the endogenous losses in weanling pigs by the regression analysis technique

Abstract

Abstract There is limited knowledge regarding trace mineral bioavailability in trace mineral supplements and common feed ingredients and trace mineral endogenous losses in pigs. The objectives of this study were to investigate intestinal responses and to determine true total tract trace mineral digestibility and the endogenous losses of trace minerals associated with corn and SBM based diets in weanling pigs by the regression analysis. Twenty-four crossbred barrows, with an average initial BW of 14 kg, were randomly assigned to 4 weanling pig diets with inclusion of titanium dioxide (0.30%) and a commercial trace mineral-vitamin premix at 0.125, 0.250, 0.375 and 0.500%, respectively, to result in 4 graded dietary levels of Cu, Zn, Fe, Mn and Se. The pigs were fed close to ad libitum for 11 d according to a randomized complete block design. The dietary inclusion did not affect (P > 0.05) growth performances, ileal and fecal DM digestibility, D-mannitol gut permeability and jejunal alkaline phosphatase kinetics. With the regression analysis, true total tract Cu, Zn, Fe, Mn and Se digestibility values (±SE; n = 23 or 24; P < 0.05) in the trace mineral-vitamin premix were determined to be 137.3±27.9, 40.5±15.4, 66.2±24.6, 94.3±21.6 and 96.6±2.8% vs. the corresponding values in the four weanling pig diets for Cu at 137.4±3.2, Zn at 40.4±3.1, Fe at 66.2±3.0, Mn at 94.2±3.8and Se at 96.2±0.8%, respectively. The total tract endogenous Cu, Zn, Fe, Mn and Se outputs (±SE)associated with the weanling pig diets were also determined (23.4±0.6, 9.2±2.7, 37.2±3.5, 19.4±1.0 and 0.07±0.003 mg/kg DMI diets; n = 23 or 24;P < 0.05). Our results have shown that the intestinal physiological functions and performances were not significantly affected in the weanling pigs fed on the diets with reduced gradient levels of a trace mineral-vitamin premix. Total tract true digestible trace mineral supply should be considered in swine diet formulation.