Predictive performance and farmer satisfaction of Jaɓnde, a digital decision-support tool for dairy-cow ration formulation: results from field assessment in Burkina Faso

International audience Background and objectives: Jaɓnde is a locally adapted ration formulation tool for resource-constrained dairy systems in sub-Saharan Africa. The version used in this study was the Excel-based prototype installed on a laptop. A mobile version, now available for free on the Google Play Store and online (jabnde.cirad.fr), is under testing. This preliminary, supervised field validation pursued three objectives: (i) to compare the technical and economic performance of zebu and crossbred cows under dairy farmer-implemented rations; (ii) to assess the implementation fidelity and the predictive performance of Jaɓnde; and (iii) to assess dairy farmer satisfaction with the use of Jaɓnde. Methodology: The tool was tested by 40 volunteer dairy farmers in the Bobo-Dioulasso milkshed (Burkina Faso) on 82 lactating cows (65 zebu, 17 crossbred). Implementation fidelity was assessed from the mean difference (predicted ration, R2 -actual ration, R3), and predictive performance from robust linear regression, reported overall and by cow type using R², the slope, and error indicators (mean absolute error, MAE; root mean square error, RMSE; mean bias error, MBE), complemented by Bland-Altman analyses. A structured survey assessed the satisfaction of dairy farmers. Results: Dairy farmers implemented R3 ration close to R2 (mean differences -0.37 to +0.04 kg GM/cow/day across feed types). Predicted and actual values were strongly associated for most variables (R² > 0.70), though weaker for milk production among crossbred cows; bias remained limited (MBE = -0.27 L/d/cow for milk production). Agreement on milk production was the most independent performance indicator. Crossbred cows produced more milk (10.6 vs 1.2 L/d/cow), whereas the relative change was greater in zebu cows (33%vs 8% increase). Over 90% of dairy farmers reported increased production and were satisfied. Contributions: This first field assessment is encouraging: under supervised conditions, farmers implemented Jaɓnde's rations, predictive performance was promising for milk production, and satisfaction was high. Confirming its causal contribution and robustness will require controlled designs across more farms, seasons, and management systems.