Studio in Vitro di un Additivo Alimentare Incapsulato: Stabilità Ruminale ed Effetti sulla Produzione di Gas e Metano

The research evaluated the ruminal stability and effects on ruminal fermentation of three microencapsulated additives supplied by the commercial company SILA s.r.l. using in vitro systems that simulate the ruminal environment. The in vitro tests were conducted using ruminal fluid taken from three Pezzata Rossa cows and combined with a buffer capable of sustaining microbial fermentation activity, while a standard lactation diet was used as the fermentation substrate. The three additives were added to the diets in three doses and in three replicates and in three successive incubations for a total of 81 incubated artificial rumens. Dry matter degradability (DMD) was assessed using the Daisy II incubator, while cumulative gas and methane production was quantified using the AnkomRF system. The concentration of methane in the headspace was analysed by gas chromatography (GC), while volatile fatty acids (VFA) were quantified by high-performance liquid chromatography (HPLC). The results showed that the microencapsulated additives maintained strong stability in the ruminal environment, with significant differences between the products tested: additives “A” and “B” showed greater degradability, especially in the first hours of incubation, reaching 26.9 ± 1.00% and 15.2 ± 0.95% at 6 hours and 37.1 ± 1.00% and 36.4 ± 1.07% at 48 hours, respectively. In contrast, additive “C” remained more persistent, with degradability values increasing more slowly from 3.2 ± 1.07% at 0 hours to 25.2 ± 1.16% after 48 hours of incubation. This demonstrated strong protection of the encapsulating matrix. The volatile fatty acid (VFA) profile and pH showed no significant variations between treatments, indicating that the additives had no significant effect on fermentation processes. Cumulative gas and methane production also showed no trends or differences between treatments. In conclusion, microencapsulation proved to be a useful strategy for preserving the integrity of bioactive compounds during ruminal fermentation. However, this also raised some critical questions regarding both the strong protection observed for the additives and the use of high dosages required by the in vitro experimental conditions, which are not directly comparable to those applicable in vivo. Further studies will be needed to validate the effectiveness of microencapsulation under real production conditions in order to assess its impact on both enteric emission mitigation and ruminal metabolism functionality.