Productive, nutritional, and economic factors associated with the Lactating Cow Feed Cost-to-Milk Revenue Ratio in small-scale dairy farms.

Small-scale dairy production contribute to food security and rural economies, but face constraints that may compromise their sustainability. This study evaluated the relationship between reproductive performance and economic efficiency using the Lactating Cow Feed Cost-to-Milk Revenue Ratio (CASI), hypothesizing that prolonged lactations associated with poor reproductive performance may increase the feed cost per unit of milk produced, thereby affecting economic efficiency. It also identified productive profiles through cluster analysis. A retrospective observational study analyzed data from 158 dairy farms participating in the Technical Support Program of the Secretaría de Agricultura y Desarrollo Rural. Reproductive, productive, nutritional, and economic variables were assessed using Pearson correlations, multiple linear regression, mixed models with interaction terms, and k-means clustering. Mean CASI was 0.58 ± 0.01. Reproductive variables were not directly associated with CASI (P > 0.05). Milk production (r = - 0.504; P < 0.001), milk sale price (r = - 0.222; P = 0.005), and herd size (r = - 0.225; P = 0.005) were negatively associated with CASI, whereas dry matter intake (r = 0.163; P = 0.041) and forage intake (r = 0.191; P = 0.016) were positively associated. The regression model explained 65.5% of CASI variation and identified significant associations with milk production, milk sale price, net energy for lactation, and feeding cost (P < 0.001). Interactions between milk production and days open (P = 0.029) and services per conception (P < 0.001) indicated production-dependent reproductive effects. Three farm profiles differed in scale, intensification, and economic performance. Overall, CASI was mainly associated with productive, nutritional, and feeding-cost variables, suggesting that improving production efficiency, nutritional management, and feed cost control may provide greater economic benefits than improving reproductive performance alone.