The objective of this work was to evaluate the microeconomic situation through the use of efficiency indicators, technical, economic and financial for production representative units (PRU) in cow-calf systems. Four scales of production (20, 40, 200 and 500 sows) comprising individuals in reproductive age were analyzed in four regions of the state of Chihuahua, Mexico. By using a panel methodology, costs and revenues were obtained during 2009 with the participation of 5-10 panel producers. We used the MEXSIM economic simulation model of the University of Texas A&M, which had been previously adapted to Mexico by the National Network of Public Policy Research. It was found that the economic viability, as measured by the probability of negative ending cash reserves and capital loss, is good for CHBC20, CHBC200 and CHBC500 and moderate for CHBC40. The lowest net income per sow was at CHBC40 ($ 27,76) while the highest was for CHBC20 ($ 403,42), and the best and worst benefit-cost ratios were 2.16 and 1.78 for CHBC500 and CHBC200, respectively. All PRUs obtained sufficient net income to cover family expenses, except for CHBC20, which only covered 70% of all expenses. The URP more scale were more profitable than small and all worked on their balance point. In fact profit margins were greater the greater the production scale, which suggests evidence of economies of scale.
Keywords: cow-calf systems, herd size, beef cattle, calves at weaning.