Essential oils and fatty acids as strategic additives for rehydrated corn grain silage

• Grant number: 23/09508-9
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: November 01, 2023
• End date: April 30, 2026
• Field of knowledge: Agronomical Sciences - Animal Husbandry
• Principal Investigator: Luiz Gustavo Nussio
• Grantee: Álvaro Bernardo da Silva Neto
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

Essential oils (EO) and fatty acids (FA) can modulate ruminal fermentation by exerting selective pressure on microbial populations. This modulation behavior has also been observed in fermentation of silages. The addition of EO to ensiled forage has resulted in a consistent increase in nutrient conservation and aerobic stability, which may favor lactic acid bacteria (LAB) populations. As for the treatment of ensiled forage with vegetable oils rich in unsaturated FA, the few available studies have reported alterations in fermentation, with promising results in nutrient conservation and increased aerobic stability. In studies with typical microorganisms from silages in culture medium, LAB were inhibited by unsaturated FA, although they developed in the presence of oleic acid. Clostridial spores were inhibited by both unsaturated and saturated medium-chain FA. This project proposes to present conservation strategies based on the use of EO and FA as additives for silage. Due to the lack of information on the subject for grain silages, different concentrations of different EO active principles and FA structures will be evaluated in viability tests on rehydrated corn grain silage, in addition to being challenged against consolidated conservation strategies involving chemical additive and microbial inoculant. Potential effects on ruminal fermentation and methane production of animals fed with silages treated with EO and FA will be evaluated in a metabolic assay with cannulated lambs.