A multiplatform metabolomic approach to characterize fecal signatures of negative postnatal events in chicks: a pilot study

摘要

Background:Negative experiences in early life can induce long-lasting effects on the welfare,health,and performance of farm animals.A delayed placement of chicks in rearing houses has negative effects on their performance,and results in fecal-specific odors detectable by rats.Based on this observation,the volatile organic compounds (VOCs) and metabolites from the feces of 12-day-old chickens were screened for early markers of response to negative events using gas-chromatography and liquid-chromatography coupled with mass spectrometry (GC-MS,LC-HRMS).Results:The low reproducibility of solid-phase micro-extraction of the VOCs followed by GC-MS was not suitable for marker discovery,in contrast to liquid extraction of metabolites from freeze-dried feces followed by GC-MS or LC-HRMS analysis.Therefore,the fecal metabolome from 12-day-old chicks having experienced a normal or delayed placement were recorded by GC-MS and LC-HRMS in two genotypes from two experiments.From both experiments,25 and 35 metabolites,respectively explaining 81％ and 45％ of the difference between delayed and control chickens,were identified by orthogonal partial least-squares discriminant analysis from LC-HRMS and GC-MS profiling.Conclusion:The sets of molecules identified will be useful to better understand the chicks' response to negative events over time and will contribute to define stress or welfare biomarkers.