Enriching the Nutritive Value of Marigold (Tagetes Erecta L) Crop Residues as a Ruminant​ Feed by Lactic Acid​ During Ensilage

Abstract

Background: Marigold (Tagetes erecta L) accounts for over half of the world's loose flower production, and marigold crop residues (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, 30 days) to determine and quantify the VOCs changes using a solid-phase microextraction (SPME) technique and gas chromatography – mass spectrometry (GC-MS). Results: After 30 days, the caryophyllene and piprocyone, which account for 14.67% and 12.17% of total VOCs, decreased by 32.86% and 9.62% respectively, alcohols increased from 2.8% to 8.13%, and the acetic acid content increased by 560%. Conclusion: The results reported in this study show that during ensilage, LAB influences type and levels of VOCs. These results have shed light on our understanding of how to improve marigold residue odor and to enhance terpene degradation by lactic acid bacteria fermentation.