Uso de Lasalocida Sódica e Óleos Essenciais na Modulação da Fermentação de Dietas Mistas Totais Ensiladas

Abstract

The use of additives such as ionophores and essential oils has been commonly adopted in ruminant diets. However, when these additives are applied during ensiling, there is a shift in fermentation patterns due to their antimicrobial action. Therefore, the objective of this study was to evaluate the use of sodium lasalocid (LASA) and essential oils (EOs) in modulating the fermentation of total mixed rations (TMR) subjected to ensiling. A completely randomized design was used, in a 4×2 factorial scheme, in which four types of additives were evaluated: control (distilled water); LASA at a dose of 375 mg/kg of dry matter (DM); limonene essential oil (OEL); and a blend based on cinnamaldehyde and carvacrol essential oils (OEB), both at a dose of 400 mg/kg DM, in two seasons of the year (summer and autumn). The fermentation period of the TMRs in the microsilos was approximately 110 days. The evaluated parameters were: fermentative losses, aerobic stability (AS), chemical–bromatological composition, and fermentation characteristics of the TMR silages.The treatments with additives resulted in higher dry matter recovery, particularly for LASA and OEB during the autumn (96.30% and 97.24% DM, respectively). No differences were observed in pH among silages produced in the summer (average of 3.82), whereas in the autumn, the treatment with OEL had the highest value (3.96). In general, the additives increased lactic acid production, except for LASA, which showed a positive effect only in the summer. Treatments with OEB showed the highest acetic acid concentrations, especially in autumn (2.17% DM), which led to greater aerobic stability (149.30 hours) and lower lactic:acetic ratios (2.95). The highest crude protein contents were observed in the autumn, particularly in the OEL treatment (19.55% DM), while no differences were found in the summer (average 16.93% DM). Treatments with LASA and OEL promoted an increase in total digestible nutrients (73.33% and 72.00% of total nitrogen, respectively). The inclusion of additives had beneficial effects on the fermentation process and nutritional quality of TMR silages, with OEB at a dose of 400 mg/kg DM standing out by providing greater dry matter recovery, increased production of organic acids, and higher aerobic stability, especially in the autumn.