Meta-analysis of the correlation between dietary copper supply and broiler performance

PLoS One. 2020 May 18;15(5):e0232876. doi: 10.1371/journal.pone.0232876. eCollection 2020.

Abstract

Objective: To conduct a meta-analysis assessing the correlation between dietary copper supply and broiler performance.

Methods: Studies that were published prior to January 2019 and reported the dietary copper supply and broiler growth performance were identified using search functions in the Web of Science, Springer, Elsevier, Science Direct, and Taylor & Francis Online databases; the Journal of Dairy Research; and China National Knowledge Infrastructure (CNKI). We performed stratified analyses on the possible sources of bias, including differences in the study locations and years of publication. The publication bias was assessed with Egger's test method.

Results: A total of 12 randomized controlled trial (RCT) studies were eligible for inclusion. The pooled WMDs of the ADG, ADFI and FCR were -0.166 (95% CI: -1.587 to 1.254), -0.844 (95% CI: -1.536 to -0.152) and -0.029 (95% CI: -0.057 to 0.000), respectively. In the Israeli and Indian studies, the ADG and ADFI data in the experimental group were higher than those in the control group; however, in America, a relatively high FCR value was found in the experimental group compared to that in the control group. The analysis of the study period showed that for the 1980s and 2010s, the ADG and ADFI of the experimental group were lower than those of the control group, while, in the 1990s and 2010s, the FCR of the experimental group were lower than those of the control group. The observed values were adjusted for study effects, and a model was used to obtain the copper supplementation under the optimal production performance. The results showed that the adjusted average daily gain (ADG), average daily feed intake (ADFI), and feed to gain ratio (FCR) presented a quadratic relationship with Cu supplementation (P<0.05). The maximum value of ADG (31.84 g/d) is reached when Cu is added at amount of 158 mg/kg, and the minimum value of FCR (1.53) is reached when Cu is added at amount of 217 mg/kg. No significant publication bias existed in the studies (Egger's test: P value were 0.81, 0.71 and 0.14).

Conclusion: From this study, it can be concluded that the traditional copper addition is no longer suitable for modern broiler breeding; the higher copper content may be beneficial for the production performance of broilers.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animal Feed
  • Animal Husbandry
  • Animals
  • Chickens* / growth & development
  • Copper* / administration & dosage
  • Diet*

Substances

  • Copper

Grants and funding

1. Chao F. Grant Number 2019BS03009, the Natural Science Foundation of Inner Mongolia, http://kjt.nmg.gov.cn/ 2. Chao F. Grant Number NJZY19230, the College and University Scientific Research Project of Inner Mongolia, http://jyt.nmg.gov.cn/ 3. Chao F. Grant Number 2018JYYB16, the Scientific Research Projects of Hulunbuir University, http://www.hlbrc.cn/ 4. Chao F. Grant Number 2018BS48, the PhD Foundation Project of Hulunbuir University, http://www.hlbrc.cn/ The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.