Microencapsulated probiotics as an alternative to antibiotics and trace elements: effect on performance and gut microbiota of weaned pigs

The use of probiotics as growth promoters in animal production has been extensively studied, yet performance outcomes vary significantly based on the strain and application method. Four dietary treatments – microencapsulated probiotic mixtures (D1 and D2), antibiotics (D3), and copper sulphate (D4) – were compared in terms on piglet growth performance, gut health, and economic profitability in a pre-fattening stage. A total of 108 piglets, aged 21 days and weighing an average of 6 kg, were randomly divided into four groups, each receiving a different diet. The experiment used three replicate pens per treatment, with nine piglets per pen. No significant differences were observed in body weight (BW) across treatment groups; however, feed intake was significantly lower for probiotic-fed piglets (D2) compared to other treatments during phase 1 and cumulatively ( P <0.05). Monte Carlo simulations, a method that uses repeated random sampling to model and predict system behaviour under uncertainty, confirmed these findings. This showed that probiotic-supplemented diets delivered higher gross margins (43%) compared to antibiotics (28%) and copper sulphate (40%). Probiotic-fed piglets exhibited significant gut microbiota modulation, characterised by reduced pathogens (e.g. Escherichia coli ) and increased beneficial bacteria, like Lactobacillus spp. These diets enhanced microbial diversity, as shown by higher Shannon and Simpson index values, which indicated improved gut resilience and overall health. In contrast, diets supplemented with antibiotics and copper sulphate showed reduced microbial diversity, highlighting the adverse impact of these treatments on gut health. This study demonstrated that encapsulated probiotics are a viable alternative to antibiotic growth promoters, supporting similar zootechnical performance while promoting gut health and enhancing profitability.