Biogas production was investigated in pilot‑scale digesters using chicken, sheep, and cow manure under mono‑ and co‑digestion at ambient conditions in Erbil City, Kurdistan Region, Iraq, with a 40‑day retention time. Mono‑digestion trials applied five dilution ratios (1:1 to 1:3), while co‑digestion used three different ratios (i.e. 1:1, 1:2, 1:3). Yield dynamics were analyzed through Modified Gompertz and First‑order models, with statistical indicators (such as R², RMSE, RSS, AIC, and BIC) used to assess performance. Results demonstrated that chicken manure consistently achieved the highest cumulative biogas and CH4 yield, reaching 323 L/kg VS and 194 L/kg VS at 1:1.5 under mesophilic regimes also, 320 L/kg VS and 192 L/kg VS at 1:2.5 ratios thermophilic regimes. While, sheep manure biogas yield peaked at 245 L/kg VS and CH4 135 L/kg VS (ratio 1:1, and mesophilic), whereas cow manure biogas and CH4 yield reached 279 L/kg VS and 153 L/kg VS (ratio 1:1.5, and mesophilic), showing improved adaptability under moderate dilution. Co‑digestion revealed pronounced synergistic effects: at the 1:1 ratio under mesophilic conditions, cumulative yield reached 576 L/kg VS nearly double that of mono‑digestion with smoother production curves and enhanced process stability. Kinetic modeling confirmed the superiority of the Modified Gompertz equation, which consistently provided robust fits (adjusted R² > 0.95, RMSE < 0.05, and low AIC/BIC), while the First‑order model often produced unstable parameters. Regression analysis further validated the Gompertz model, presenting excellent agreement between predicted and experimental yields (R² = 0.991). This case study demonstrates the resilience of chicken manure, the moderate but dilution sensitive performance of sheep manure, and the adaptability of cow manure under mesophilic regimes. Co digestion provided clear synergistic benefits, and regression based kinetic modeling was validated as a reliable framework for predicting biogas yield. Together, these findings deliver baseline insights for decentralized biogas production in the Kurdistan Region of Iraq.