An analysis of the available information of years 2006 and 2007 at diverse sources in dependences, institutions and commercialization systems of cattle in Sonora was made. We analyzed international price fluctuation data of corn with base in information of stock-market of Chicago. From the previous information, data that allowed analyzing the present price behavior, weight and seasons were generated at which the yearling calves leave to the market through the year in the state of Sonora. Results show that this type of cattle is sold throughout the year, showing two picks at which the affluence is greater: in March and November. Depending on the condition of the animals, these classify like yearling calves number one (European type), one and a half (crossed) and two (Creole or zebu), with average monthly weights that fluctuate between 165 and 187 kilograms; average monthly price by kilogram of 22 to 28 pesos. Through these two years, animal weight as well as the sale price has had marked fluctuations, displaying declining tendencies in both cases. In this study, it was observed a noticeable and proportional inversely effect between these tendencies and the international prices of cereals and the bioenergetics.