评估 litter 处理对 litter 质量和肉鸡性能的影响：系统评价和荟萃分析。
An assessment of the impacts of litter treatments on the litter quality and broiler performance: A systematic review and meta-analysis.
机构信息
Department of Animal Science, Faculty of Agronomy Eliseu Maciel, Federal University of Pelotas, Pelotas, Brazil.
Ibirubá Campus, Federal Institute of Education, Science and Technology of Rio Grande do Sul, Ibirubá, Brazil.
出版信息
PLoS One. 2020 May 6;15(5):e0232853. doi: 10.1371/journal.pone.0232853. eCollection 2020.
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.
目的
最适合的垫料处理方式的选择应基于科学证据。本系统评价评估了垫料处理对垫料中氨浓度、pH 值、水分和病原微生物群落的有效性，及其对肉鸡体重、采食量、饲料转化率和死亡率的影响。
方法
使用 PubMed（Medline）、Google Scholar、ScienceDirect 和 Scielo 数据库进行系统文献检索，检索 1998 年 1 月至 2019 年 8 月发表的文章。从每项研究中提取均值、标准差和样本量。使用均值差（MD）或标准化均值差（SMD）（垫料处理组减去对照组）分析反应变量。使用随机效应荟萃分析分析所有变量。
结果
亚组荟萃分析显示，酸化剂降低了垫料的 pH 值（P<0.001）、水分（P = 0.002）、氨浓度（P = 0.011）和病原微生物群落（P <0.001），并提高了肉鸡的体重增长率（P = 0.019），降低了死亡率（P<0.001）。与对照组相比，石膏对氨减排（P = 0.012）和改善饲料转化率（P = 0.023）有积极影响。碱化剂提高了 pH 值（P = 0.035），恶化了饲料转化率（P<0.001），增加了死亡率（P <0.001），降低了垫料水分（P<0.001），减少了垫料中的病原微生物群落（P<0.001）。与对照组相比，过磷酸钙和吸附剂分别降低了 pH 值（P<0.001）和垫料水分（P = 0.007）。
结论
垫料处理方式均不影响肉鸡的采食量。对选定研究的荟萃分析表明，与对照组相比，垫料处理对肉鸡生产性能和垫料质量有积极和显著的影响。碱化处理与较差的饲料转化率和肉鸡死亡率升高有关。
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