Chemical characteristics and relative bioavailability of supplemental organic zinc sources for poultry and ruminants.

Abstract

Eight commercially available organic Zn products and reagent-grade ZnSO4 x 7H2O (Zn Sulf) were evaluated by polarographic analysis, and solubility in .1 M K2HPO4-KH2PO4 buffer (pH 5), .2 M HCl-KCl buffer (pH 2), and deionized water. Fractions from these solubility tests were evaluated by gel filtration chromatography for structural integrity. Degree of chelation was generally positively related to chelation effectiveness determined by polarography. The organic sources were Zn methionine complex A (Zn MetA), Zn methionine complex B (Zn MetB), Zn polysaccharide complex (Zn Poly), Zn lysine complex (Zn Lys), Zn amino acid chelate (Zn AA), Zn proteinate A (Zn ProA), Zn proteinate B (Zn ProB), and Zn proteinate C (Zn ProC). Three experiments were conducted to estimate the relative bioavailability of Zn from the organic Zn supplements for chicks and lambs when added at high dietary levels to practical diets. Bone Zn concentration increased (P < .001) as dietary Zn increased in both experiments. When Zn Sulf was assigned a value of 100% as the standard, multiple linear regression slope ratios of bone Zn from chicks fed 3 wk regressed on dietary Zn intake gave estimated relative bioavailability values of 83 +/- 14.6 and 139 +/- 16.9 for Zn AA and Zn ProA, respectively, in Exp. 1 and 94 +/- 11.6, 99 +/- 8.8, and 108 +/- 11.4 for Zn Poly, Zn ProB, and Zn ProC, respectively, in Exp. 2. In Exp. 3, 42 lambs were fed diets containing Zn Sulf, Zn ProA, Zn AA, or Zn MetB for 21 d. Based on multiple linear regression slope ratios of liver, kidney, and pancreas Zn and liver metallothionein concentrations on added dietary Zn, bioavailability estimates relative to 100% for Zn Sulf were 130, 110, and 113 for Zn ProA, Zn AA, and Zn MetB, respectively. Except for Zn ProA, which was greater, the organic Zn supplements had bioavailability values similar to that of Zn Sulf for chicks and lambs. Bioavailability of organic Zn products was inversely related to solubility of Zn in pH 5 buffer in chicks (r2 = .91) and pH 2 buffer in lambs (r2 = .91), but not to an estimate of degree of chelation.

Zinc availability and digestive zinc solubility in piglets and broilers fed diets varying in their phytate contents, phytase activity and supplemented zinc source

“…The percentage of Zn present in a soluble form (Zn solubility) may be related to digesta pH (Figure 1) (7% to 16%, respectively) and 10% to 18% of Zn were soluble in piglet stomach and intestine, while these percentages were 26% to 32% and 9% to 14% in the broiler gizzard and intestine, respectively. Furthermore, Zn solubility was also found to be higher as a consequence of lower pH in vitro (Cao et al, 2000). The stomacal Zn solubility was low (54% to 84% on 100 kg BW pigs) compared to measures observed by Dintzis et al (1995) even though pH was 4.5 and extraction methods for measuring soluble Zn were similar.…”

“…Previous Schlegel, Nys and Jondreville research suggested that Zn availability depends on Zn solubility in the digesta (Susaki et al, 1999), whereas Zn solubility may depend on various factors including digesta pH (Cao et al, 2000;Jongbloed et al, 2002), dietary Zn concentration (Dintzis et al, 1995;Susaki et al, 1999), supplemented Zn source (Cao et al, 2000) and interactions between dietary Zn and diet composition (Ammerman et al, 1995;Jongbloed et al, 2002).…”

Bioavailability of zinc sources and their interaction with phytates in broilers and piglets

“…The data from Analysis I suggests that broilers are more efficient in using ZN N than piglets and the data from Analysis II show that ZN N was negatively affected by PP NH in piglets and that Phytase S was more efficient in piglets to improve ZN N bioavailability than in broilers. Zinc bioavailability results from dietary Zn solubility in the digestive tract before absorption (Susaki et al, 1999), which is dependent from pH conditions (Cao et al, 2000;Jongbloed et al, 2002). Early in 1963, Lease measured that 66% of Zn from soybean meal was soluble when the raw material was previously digested with pepsin at pH 3, followed with an alcalinization to pH 6.8.…”

The effect of inorganic and organic form of zinc on digestibility of nutrients in dairy cows in three stages of reproductive cycle

“…Close and Cole, 2003), it is possible to say generally, that the complex zincmethionine, is about two times more available than zinc oxide. CAO et al (2000) reported that the absorption of zinc-proteinate, zinc-amino acid chelate and zinc-polysaccharide were 83 to 139 percent of zinc sulfate (set at 100 %). Further, ŠIMEK et al (2000) observed that addition of zincmethionine had positive impact on increasing production and milk quality, fertility and health.…”