Impact of Agroindustrial Waste Fermented with Bacteria and Yeasts and Their Effect on Productive, Hematological, and Microbiota Indicators in Guinea Pigs (<i>Cavia porcellus</i>)

In the last decade, the production of guinea pig meat in Andean countries has increased due to the growing number of consumers of this meat. Objective: To evaluate the effect of including different doses (0.50, 1.00, and 1.50 mL) of agro-industrial substrates (molasses distillery waste) fermented with lactic acid bacteria and yeasts on productive performance, hematological profile, relative weight changes in digestive tract organs, and changes in the intestinal microbiota in guinea pigs (<i>Cavia porcellus</i>). Materials: A total of 300 guinea pigs, Kuri breed, aged 20 days and weighing 330 g, were distributed into 10 groups of 30 animals each. Ctrl, Control. La, substrate fermented with <i>Lactobacillus acidophilus</i> (8.1 × 10⁷ CFU/mL). Kf, substrate fermented with <i>Kluyveromyces fragilis</i> (7.4 × 10⁶ CFU/mL). La + Kf, substrate fermented with bacteria and yeasts; the evaluated doses were 0.50, 1.00, and 1.50 mL/animal. The indicators evaluated in the study included weight gain, health, hematological profile, relative weight of digestive tract organs, and changes in the intestinal microbiota. Results: The parameters evaluated were toxicity, productive parameters, occurrence of diarrhea and mortality, and blood profile. The results showed a significant increase in the weight of the animals consuming probiotics, especially at higher doses. Additionally, an improvement in the intestinal microbiota was observed, with an increase in beneficial bacteria such as <i>Lactobacillus</i> and a decrease in pathogenic bacteria. Probiotics also influenced the hematological parameters and the weight of digestive tract organs, suggesting a positive effect on the overall health of the animals. Conclusions: Supplementation with probiotics proved to be a promising strategy for improving productive performance and intestinal health in guinea pigs. Supplementation with <i>L. acidophilus</i> and <i>K. fragilis</i> significantly enhances guinea pig growth and modulates the intestinal microbiota. The combination of strains and appropriate doses maximizes benefits. These results promise applications in animal production, requiring further studies to confirm their efficacy in other species and developmental stages.