几种氧化锌、硫酸锌和金属锌来源中锌的生物利用度。

Bioavailability of zinc in several sources of zinc oxide, zinc sulfate, and zinc metal.

作者信息

Edwards H M, Baker D H

机构信息

Department of Animal Sciences, University of Illinois, Urbana 61801, USA.

出版信息

J Anim Sci. 1999 Oct;77(10):2730-5. doi: 10.2527/1999.77102730x.

DOI:10.2527/1999.77102730x

PMID:10521034

Abstract

Three zinc depletion-repletion assays were carried out with chicks to determine Zn bioavailability in five sources of ZnO, three sources of ZnSO4.H2O, and two sources of Zn metal. A standard 23% CP corn-soybean meal diet was fed during the first 3 d posthatching, after which it was replaced with a Zn-deficient soy concentrate diet (13.5 mg Zn/kg) until d 7. On d 8 after an overnight period of feed withdrawal, chicks were fed for 12 d the Zn-deficient basal diet containing 0, 4.76, and 9.90 (Assay 1); 0, 5.06, or 10.12 (Assay 2); or 0, 4.73, or 9.13 (Assay 3) mg/kg supplemental Zn from analytical grade (AG) ZnSO4.7H2O (22.7% Zn) to generate a standard response curve. The AG and feed-grade (FG) Zn sources being evaluated were then provided at a level that would fall within the standard curve. Weight gain (Assays 1, 2, and 3) and total tibia Zn (Assay 1) responded linearly (P<.01) to Zn supplementation from ZnSO4.7H2O. Weight gain regressed on supplemental Zn intake gave standard-curve equations with fits (r2) ranging from .94 to .97. In Assay 1, regression of total tibia Zn (Y, in micrograms) on supplemental Zn intake (X, in milligrams/12 d) gave the equation Y = 13.2+6.74X (r2 = .90). Standard-curve methodology was used to estimate relative Zn bioavailability (RBV), with RBV of Zn in the ZnSO4.7H2O standard set at 100%. Four sources of FG ZnO were evaluated: Source 1 (78.1% Zn, hydrosulfide process, U.S.), Source 2 (74.1% Zn, Waelz process, Mexico), Source 3 (69.4% Zn, China), and Source 4 (78.0% Zn, French process, Mexico). Analytical-grade ZnO (80.3% Zn) was also evaluated. Feed-grade ZnO Sources 1 and 4 as well as AG ZnO produced average RBV values that were not different (P>.10) from the standard, but average RBV values for FG Source 2 and FG Source 3 were only 34 (P<.05) and 46% (P<.05), respectively. All sources of ZnSO4.H2O, which included two FG sources (source 1, 36.5% Zn; source 2, 35.3% Zn) and one food-grade source (36.5% Zn), were not different (P>.10) in RBV from the ZnSO4.7H2O standard. Two Zn metal products, Zn metal dust (100% Zn) and Zn metal fume (91.5% Zn), were also evaluated, and they were found to have Zn RBV values of 67 (P<.05) and 36% (P<.05), respectively. Feed-grade sources of ZnO vary widely in color, texture, Zn content, and Zn bioavailability.

摘要

用雏鸡进行了三项锌耗竭-补充试验，以测定5种氧化锌来源、3种七水硫酸锌来源和2种金属锌来源中的锌生物利用率。孵化后前3天饲喂标准的23%粗蛋白玉米-豆粕日粮，之后换成缺锌的大豆浓缩物日粮（锌含量13.5毫克/千克），直至第7天。在第8天，禁食过夜后，雏鸡饲喂含0、4.76和9.90（试验1）；0、5.06或10.12（试验2）；或0、4.73或9.13（试验3）毫克/千克来自分析纯（AG）七水硫酸锌（锌含量22.7%）的补充锌的缺锌基础日粮12天，以生成标准反应曲线。然后以落在标准曲线范围内的水平提供被评估的AG和饲料级（FG）锌源。体重增加（试验1、2和3）和胫骨总锌含量（试验1）对来自七水硫酸锌的锌补充呈线性反应（P<0.01）。体重增加量与补充锌摄入量的回归得出拟合度（r2）在0.94至0.97之间的标准曲线方程。在试验1中，胫骨总锌含量（Y，微克）与补充锌摄入量（X，毫克/12天）的回归得出方程Y = 13.2 + 6.74X（r2 = 0.90）。采用标准曲线法估算相对锌生物利用率（RBV），七水硫酸锌标准品中锌的RBV设定为100%。评估了4种FG氧化锌来源：来源1（锌含量78.1%，美国硫化氢法）、来源2（锌含量74.1%，墨西哥瓦尔兹法）、来源3（锌含量69.4%，中国）和来源4（锌含量78.0%，墨西哥法国法）。还评估了分析纯氧化锌（锌含量80.3%）。饲料级氧化锌来源1和来源4以及AG氧化锌产生的平均RBV值与标准品无差异（P>0.10），但FG来源2和FG来源3的平均RBV值分别仅为34%（P<0.05）和46%（P<0.05）。所有七水硫酸锌来源，包括2种FG来源（来源1，锌含量36.5%；来源2，锌含量35.3%）和1种食品级来源（锌含量36.5%），其RBV与七水硫酸锌标准品无差异（P>0.10）。还评估了2种金属锌产品，金属锌粉（锌含量100%）和金属锌烟（锌含量91.5%），发现它们的锌RBV值分别为67%（P<0.05）和36%（P<0.05）。饲料级氧化锌来源在颜色、质地、锌含量和锌生物利用率方面差异很大。