Silagem de trigo com diferentes aditivos e tempos de armazenamento

Abstract

The objective of this study was to evaluate the microbiological quality of wheat silage of the cultivar Energix 202 with added sugar and/or microbial inoculant, at different storage times. The design used was completely randomized, with 4 replications, in split plots in time. Four silages were evaluated: a wheat silage (ST) without additives, representing the control group; one with sugar additive (STA); another with microbial inoculant (STI); and, finally, one with sugar and microbial inoculant (STIA) at 0 (in natura), 28, 56, 84, 112, 140, and 168 days of storage. The silages with sugar and inoculant (STIA) presented pH between 3.8 and 4.5, setting the period of aerobic stability already in the fourth week of storage. There was a significant difference between the averages of the treatments for the different silage groups regarding the dry matter (DM) content, and the silages with added sugar and the inoculated silages presented lower DM content in relation to the control group. All treatments showed values greater than 40% DM at all opening times, with a reduction in dry matter content with increasing opening time. The effluent losses (PE) did not differ between the silages; as for the dry matter recovery (RMS), the wheat silages with inoculant and inoculant + sugar were equally superior when compared to the others. As for the gaseous losses (PG), the control group and the wheat silage with sugar showed greater losses. There was a difference between silages and storage times to evaluate the population of lactic acid bacteria (LAB) colonies. The inclusion of sugar favored the amount of LAB at 28 and 56 days of storage. Wheat silages with and without inoculants and sugar obtained amounts of Clostridium at safe levels. Silage with inoculant decreased Clostridium counts and reduced dry matter losses. The silage with added sugar without inoculant improved the fermentative profile of the wheat silage, keeping the pH in the ideal range during the 168 days of storage, in addition to reducing losses by gases and effluents. The added sugar in wheat silage provided better fermentation than when no additive was used, but did not result in an additive effect when used combined with the bacterial inoculant.