Fungos de alimentação direta e suas influências nas características da silagem de milho planta inteira.

Abstract

Corn silage is widely used during forage shortages to meet the nutritional demands of ruminants, especially in pasture-based production systems. During these times, it is also common to provide animals with antibiotics, which act as growth promoters. However, there are a series of restrictions, especially in Europe, regarding the use of these products due to their negative effects on human health. In this context, Direct Feeding Fungi (DFF) have gained prominence due to their potential to optimize ruminant performance through various modes of action. However, the effectiveness of DFF is influenced by the nutritional composition of the diet and the method of administration used. It is important to note that the effects of DFF on the quality of whole-plant corn silage, when used as a vehicle for delivery, are still poorly understood. Therefore, the aim was to evaluate the influences of the DFF Paecilomyces lilacinus and Trichoderma longibrachiatum on the characteristics of whole-plant corn silage. The microbiological profile, pH, ammonia nitrogen (N-NH3/NT), aerobic stability, gas losses, effluent, dry matter, chemical composition, and in vitro dry matter digestibility (IVDMD) were analyzed. Sixty minisilos were used in five treatments, with six repetitions and two experimental periods (45 and 90 days). The treatments were: CTL: no microorganisms added; COM: commercial product; FPL: Paecilomyces lilacinus; FTL: Trichoderma longibrachiatum; and FPT: a 1:1 mixture of Paecilomyces lilacinus and Trichoderma longibrachiatum. The design was completely randomized with a 5×2 factorial arrangement and 5% significance by Tukey's test. The DFF did not survive the silage process. Aerobic stability was 30 hours in both treatments and times. The FPT showed higher gas and dry matter losses (P ≤ 0.01), while FPL reduced these losses. The effluent loss was similar between treatments and times; however, FPL exhibited a more pronounced loss after 90 days (P ≤ 0.01). The pH increased during the evaluation (P ≤ 0.01). After 45 days, the CTL showed less fiber (P ≤ 0.01), and FPT had the highest crude protein (P ≤ 0.01). FPL showed the lowest acid-detergent insoluble fiber at 90 days (P ≤ 0.01) and the lowest N-NH3/NT (P ≤ 0.01) and highest IVDMD (P ≤ 0.01) after 45 and 90 days. It is concluded that Paecilomyces lilacinus reduced losses and increased digestibility, being promising as an additive for silage.