Beef production has been in the spotlight of the climate change debate since 2006, when FAO overestimated its impact on green house gas (GHG) emissions. Uruguay’s beef sector develops over the Pampas biome taking advantage of the natural grasslands. The sector is structured in a value chain that comprises different processes at the rancher level: cow-calf, stocker, fattening, or complete cycle are different arrangements that differs in time and technical processes. Uruguay is a significant exporter of beef (ranks 9th worldwide), and is recognized for the quality of pasture based meat. In the last 30 years the country has improved the beef fattening production process reducing the age of animal slaughter. However, the cow-calf system faces efficiency issues, leading to situations where it is sometimes more convenient to slaughter unproductive or even pregnant cows rather than improve the weaning percentage. Over the last 20 years, the sector has undergone significant changes, with 80% of its production now geared towards export and approximately 25% of the domestic market being supplied by neighboring countries. International markets, especially those with higher prices, are increasingly focused on the environmental impacts of production processes. This paper aims to estimate technical efficiency and the role of weather on the cow-calf management at the smallest administrative unit. It is a preliminary step toward understanding the production decisions involved in cattle ranch management.