Abstract：
The higher availability of zinc (Zn) from organic than inorganic sources is already established, but more assertive and cost-friendly protocols on the total replacement of inorganic with organic Zn sources for laying hens still need to be developed. Because some discrepancy in the effects of this replacement in laying hen diets is noticeable in the literature, the objective of this meta-analysis was to properly quantify the effect size of total replacing inorganic Zn with organic Zn in the diet of laying hens on their laying performance, egg quality, and Zn excretion. A total of 2340 results were retrieved from Pubmed, Scielo, Scopus, WOS, and Science Direct databases. Of these, 18 primary studies met all the eligibility criteria and were included in this meta-analysis. Overall, the replacement of inorganic Zn with organic Zn, regardless of other factors, improved (p < 0.01) egg production by 1.46%, eggshell thickness by 0.01 mm, and eggshell resistance by 0.11 kgf/cm2. Positive results of the same nutritional strategy on egg weight and Zn excretion were only observed at specific conditions, especially when organic Zn was supplemented alone in the feed, not combined with other organic minerals. Therefore, there is evidence in the literature that the total replacement of inorganic Zn with organic Zn improves egg production, eggshell thickness, and eggshell resistance. Factors such as hen age and genetics, organic Zn source, concentration of Zn in the feed, and the strategy of its supplementation have to be more carefully considered in protocols designed to address egg weight and Zn excretion by the hen.
摘要：
已经建立了来自有机来源的锌（Zn）比来自无机来源的更高的可用性，但是，仍然需要开发更自信和成本友好的方案，以完全用有机Zn源替代蛋鸡的无机物。因为在文献中，这种替代蛋鸡饮食的效果存在一些差异，这项荟萃分析的目的是适当量化蛋鸡日粮中有机锌替代无机锌对其产蛋性能的影响大小，鸡蛋质量,和锌排泄。共从Pubmed检索到2340个结果，Scielo,Scopus,WOS,和科学直接数据库。其中,18项主要研究符合所有资格标准，并纳入本荟萃分析。总的来说,用有机锌代替无机锌，不管其他因素,鸡蛋产量提高了1.46%(p<0.01)，蛋壳厚度为0.01毫米，蛋壳阻力为0.11kgf/cm2。仅在特定条件下观察到相同的营养策略对鸡蛋重量和锌排泄的积极结果，特别是当饲料中单独补充有机锌时，不与其他有机矿物质结合。因此,文献中有证据表明，用有机锌完全替代无机锌可以提高鸡蛋的产量，蛋壳厚度,和蛋壳抵抗。母鸡年龄和遗传等因素，有机锌源，饲料中锌的浓度，在旨在解决母鸡蛋重和锌排泄的方案中，必须更仔细地考虑其补充策略。
