An assessment of the impacts of litter treatments on the litter quality and broiler performance: A systematic review and meta-analysis

PLoS One. 2020 May 6;15(5):e0232853. doi: 10.1371/journal.pone.0232853. eCollection 2020.

Abstract

Objective: The choice of the most suitable litter treatment should be based on scientific evidence. This systematic review assessed the effectiveness of litter treatments on ammonia concentration, pH, moisture and pathogenic microbiota of the litter and their effects on body weight, feed intake, feed conversion and mortality of broilers.

Methods: The systematic literature search was conducted using PubMed (Medline), Google Scholar, ScienceDirect and Scielo databases to retrieve articles published from January 1998 to august 2019. Means, standard deviations and sample sizes were extracted from each study. The response variables were analyzed using the mean difference (MD) or standardized mean difference (SMD), (litter treatment minus control group). All variables were analyzed using random effects meta-analyses.

Results: Subgroup meta-analysis revealed that acidifiers reduce pH (P<0.001), moisture (P = 0.002) ammonia (P = 0.011) and pathogenic microbiota (P <0.001) of the litter and improves the weight gain (P = 0.019) and decreases the mortality rate of broilers (P<0.001) when compared with controls. Gypsum had a positive effect on ammonia reduction (P = 0.012) and improved feed conversion (P = 0.023). Alkalizing agents raise the pH (P = 0.035), worsen feed conversion (P<0.001), increase the mortality rate (P <0.001), decrease the moisture content (P<0.001) and reduce the pathogenic microbiota of the litter (P<0.001) once compared to controls. Superphosphate and adsorbents reduce, respectively, pH (P<0.001) and moisture (P = 0.007) of the litter compared to control groups.

Conclusion: None of the litter treatments influenced the feed intake of broilers. Meta-analyses of the selected studies showed positive and significant effects of the litter treatments on broiler performance and litter quality when compared with controls. Alkalizing was associated with worse feed conversion and high mortality of broilers.

Publication types

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

MeSH terms

  • Acids / analysis
  • Acids / pharmacology
  • Acids / toxicity
  • Alkalies / analysis
  • Alkalies / pharmacology
  • Alkalies / toxicity
  • Ammonia / analysis
  • Animal Feed
  • Animal Husbandry / methods*
  • Animals
  • Bird Diseases / mortality
  • Body Weight
  • Chickens / growth & development
  • Chickens / physiology*
  • Feeding Behavior
  • Housing, Animal* / statistics & numerical data
  • Humidity
  • Hydrogen-Ion Concentration
  • Microbiota
  • Waste Management
  • Weight Gain

Substances

  • Acids
  • Alkalies
  • Ammonia

Grants and funding

The Brasil Foods S/A provided financial support in the form of author' salary to MADP but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The authors Fábio Leivas Leite and Victor Fernando Büttow Roll were supported by grants from Conselho Nacional de Desenvolvimento Científico e Tecnológico, Brazil (CNPq/Produtividade em Pesquisa). The Author Aline Arassiana Piccini Roll was supported by grant from CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Brazil. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.