Bioinoculante na silagem de milho com diferentes densidades de compactação

Abstract

Factors such as inadequate management and low packing density during ensiling can lead to the deterioration of the ensiled material, resulting in nutrient losses and reduced degradability. The development of new biotechnologies can help mitigate these negative impacts, improving the quality of silage offered to cattle. This study measured the impact of applying a bioinoculant derived from predominantly lactic fermentation in corn silage at different packing densities. Two experiments were conducted under controlled conditions, using material from transgenic corn plants to ensure uniformity. In Experiment 1, the treatments consisted of five dosages of the bioinoculant at two packing densities, totaling ten treatments with five replicates each (mini PVC cylindrical silo). In Experiment 2, a dosage of 4.0 L per ton was tested against a commercial inoculant at two storage densities, totaling four treatments with five replicates each. Analyses conducted to evaluate fermentation quality included quantifying fermentation losses at the end of the process, chemical composition and in vitro degradability analyses of the material, and monitoring aerobic stability to verify resistance to deterioration during air exposure. Principal component analysis and correlograms were applied to interpret multivariate effects among the treatments. The results indicated significant interactions between bioinoculant dosages and packing densities on the studied variables. In Experiment 1, the effect of densities was low, being compensated by the use of the bioinoculant, which showed better performance at lower densities. The use of the bioinoculant significantly reduced fermentation losses at doses of 2, 4, and 6 L/ton, achieving aerobic stability after silo opening for over 108 hours. It had a higher proportion of hemicellulose and cellulose, with pH values below 3.0, but with reduced degradability and non-fibrous carbohydrates. In Experiment 2, the tested bioinoculant demonstrated greater stability after opening, reaching over 90 hours, with a pH below 4.0, while the commercial product maintained stability for only 50 hours. Losses in both products were below 10%, and the commercial product showed higher levels of non-fibrous carbohydrates and greater degradability. Therefore, the study highlights the efficacy of including 4 L/ton of the bioinoculant in reducing losses and increasing stability after silo opening, regardless of packing density, demonstrating its ability to modulate the fermentation process towards silage preservation.