Lasalocida sódica e óleos essenciais como modificadores da fermentação em silagens de dieta completa

Abstract

This study aimed to evaluate the effects of different doses of sodium lasalocid (LASA), limonene essential oil (LEO), and a blend of essential oils containing cinnamaldehyde and carvacrol (BCC) on the fermentation process and nutritional quality of total mixed ration (TMR) silages based on BRS Capiaçu grass. The experiment was divided into two trials (one for each additive), which were repeated across two seasons (summer and autumn). In each trial, 20 experimental silos were used, testing LASA doses of 0, 225, 300, and 375 mg/kg of dry matter (Trial 1), and LEO and BCC doses of 0, 200, 400, and 600 mg/kg of DM (Trial 2). PVC silos with a capacity of 3.8 liters were used. The forage-to-concentrate ratio was 33:67 on a dry matter basis. Each trial followed a completely randomized design, with four treatments and five replicates per treatment. TMR samples were analyzed for chemical-bromatological composition, losses, fermentation quality, and aerobic stability. A linear increase in dry matter recovery and lactic acid concentration was observed with increasing LASA application rates. The application of 300 mg/kg DM of LASA resulted in the highest pH value; however, the variation among the tested doses was minimal, ranging from 3.83 to 3.93. Additionally, increasing LASA doses led to a statistically significant linear reduction in ethanol concentrations in the silages (P < 0.01). Aerobic stability analysis also showed a tendency for improvement in LASA-treated silages, although this effect was not statistically significant (p = 0.09). No significant differences were found among treatments regarding chemical-bromatological composition (p > 0.05). For LEO, a significant increase in silage dry matter was observed, with a linear rise of 0.047% per mg/kg (p = 0.02). A significant increase in lactic acid production was also recorded (p = 0.03). There was no significant change in pH (p > 0.05). However, a negative effect on aerobic stability was observed, with reduced stability time at higher doses (p = 0.01). LEO also reduced ethanol production in the TMR silages (p = 0.04). The inclusion of BCC in TMR silages increased fiber fractions (NDF and ADF) (p < 0.01) and reduced non-fibrous carbohydrates (p = 0.02), negatively impacting total digestible nutrients (TDN) (p = 0.03). BCC was also effective in improving dry matter recovery (p = 0.02), reducing effluent losses (p = 0.01), increasing lactic acid production (p = 0.04), and reducing ethanol production (p = 0.03). Aerobic stability was positively influenced by BCC, with a significant improvement observed at the 600 mg/kg dose (p = 0.01). It can be concluded that LASA, LEO, and BCC positively influence the fermentative characteristics and nutritional quality of TMR silages based on BRS Capiaçu grass, especially regarding dry matter recovery, organic acids, and aerobic stability. The optimal doses were 375 mg/kg DM for LASA, 200 mg/kg DM for LEO, and 600 mg/kg DM for BCC.