Economic and Nutritional Determinants of the Adoption of Good Health Practices in Livestock Farming: A Panel Analysis of Poultry Value Chains in the CEMAC Zone
This study analyzes the economic, nutritional and structural determinants of the adoption of good sanitary practices (vaccination, biosecurity, preventive feeding) in poultry farming in six CEMAC countries (Cameroon, Congo, Gabon, Equatorial Guinea, Central African Republic, Chad). Using an unbalanced panel of 138 observations (2000-2022, 6 countries) and 2023-2025 projections used for sensitivity purposes, we estimate a random-effects ordered logit (and probit) model by the Gauss-Hermite quadrature method (Butler and Moffitt, 1982), which controls for unobserved country heterogeneity and the temporal persistence of decisions. The results show that feed nutritional quality, agricultural income, access to credit, herd size, cooperative membership and veterinary services significantly increase the probability of adoption, whereas distance to input markets and epidemics reduce it. Selling price has no significant effect. The intra-class correlation parameter (ρ = 0.622) confirms strong unobserved heterogeneity. Operational critical thresholds are identified (nutritional index ≥ 58, income ≥ 302,000 FCFA/month, herd size ≥ 28 heads, veterinary visits ≥ 4/year, distance < 25 km); these values are indicative at the aggregated level of the six countries and require validation at finer spatial scales before any direct application. Post-estimation tests (LR, Hosmer Lemeshow, Andrews, VIF, bootstrap, ROC) validate the model's robustness. The study recommends targeted policies to strengthen cooperatives, access to credit and local veterinary services.