This study evaluated different feeding strategies on growth performance of guinea pigs (Cavia porcellus) in Ecuador’s Andean region. Using a randomized design, we divided 80 guinea pigs (320–400 g initial weight) into four treatment groups: alfalfa with balanced feed (A), ryegrass with balanced feed (R), corn husks with balanced feed (CH), and a control receiving mixed forages (T). We monitored growth for seven weeks post-weaning. Statistical analysis using ANOVA and ANCOVA revealed significant differences between treatments (p<0.001). The alfalfa group showed the highest weight gain (842.1±77.7 g), followed by ryegrass (778.5±88.4 g), corn husks (602.6±46.2 g), and control (222.9±22.5 g). Post-hoc tests showed no significant difference between alfalfa and ryegrass treatments (p>0.05), while all other comparisons showed significant differences. These findings demonstrate that supplementing guinea pig diets with alfalfa or ryegrass alongside balanced feed significantly improves growth performance compared to traditional feeding practices, providing valuable insights for optimizing guinea pig production in Andean communities.