Enriching the nutritive value of marigold (Tagetes erecta L) crop residues as a ruminant feed by lactic acid bacteria during ensilage

BackgroundMarigold (Tagetes erecta L) accounts for over half of the world's loose flower production, and marigold crop residue (MCR) are abundantly available and should be used as a forage. In this study, MCR from the last commercial flower pickings was ensilaged with lactic acid bacteria (LAB) and the shift in their volatile organic compounds (VOCs) profiles was monitored. Samples were collected at 6 different times during ensilage (3, 6, 9, 12, 15, 30days) to determine and quantify the VOCs changes using a solid-phase microextraction (SPME) technique and gas chromatography - mass spectrometry (GC-MS).ResultsAfter 30days, the caryophyllene and piperitone, which account for 14.7 and 12.1% of total VOCs, decreased by 32.9 and 9.6% respectively, alcohols increased from 2.8 to 8.1%, and the acetic acid content increased by 560%.ConclusionWe have confirmed LAB can degrade the content of terpenes and enhance the content of alcohols and acids in MCR, which was for the first time on terpene degradation in fodder by ensilage. These results have shed light on our understanding of how to improve fodder odor and to enhance terpene degradation by lactic acid bacteria fermentation.

Automated summary

The study showed that lactic acid bacteria can degrade terpenes and increase alcohols and acids in marigold crop residue during ensilage, leading to improved fodder odor and enhanced terpene degradation.