The effects of micronutrients on pullets and broilers

Abstract

Two experiments were conducted to determine the availability of various vitamin E (E) sources (absorbed to verxite or adsorbed to silica) in broilers. In Experiment 1, at 100 and 300 IU supplemental E, an average of 94 and 44% of E intake from verxite and silica, respectively, was excreted in the feces, but at 30 IU E, 49 and 45% of E intake was excreted in the feces. In Experiment 2 at 30 IU, 52 and 43% of E intake from verxite and silica was excreted (source, P < 0.02). Based on these results, E adsorbed to silica is more available. Two experiments were conducted to determine the relative bioavailability of organic versus inorganic sources of either Mn or Zn. In Experiment 1, Mn as MnSO4 or a Mn amino acid complex (Availa-Mn) were compared. In Experiment 2, ZnSO4 or a Zn amino acid complex (Availa-Zn) were compared. The results indicate that Availa-Mn is a more available source of Mn than MnSO4, but Availa-Zn is not as available as a source of Zn as ZnSO4. An experiment was conducted to determine the effects of organic sources of Zn, Mn, and Cu on White Leghorn pullet performance. Treatment diets consisted of a control diet with 66 ppm Zn as ZnSO4 or a combination of ZnSO4 and Availa-Zn, 66ppm Mn as MnSO4 or a combination of MnSO4 and Availa-Mn, and 10 ppm Cu as CuSO4 or a combination of CuSO4 and a Cu amino acid complex (Availa-Cu). Diets are inorganic sources (IO), organic Zn (OZ), organic Zn and Mn (OZM), or organic Zn, Mn, and Cu (OZMC). Addition of OZM increased (P < 0.08) intestinal tensile strength and increased (P < 0.06) grams of ash per bone compared with OZMC. Pullets fed OZ had a higher (P < 0.08) bone concentration of all minerals than pullets fed OZM. Total tibia Mn was decreased (P < 0.06) by OZMC, but total tibia Cu was increased (P < 0.08) by OZ addition over IO or OZM.