Principales variables que afectan la pre？ez en rodeos de cría de la Cuenca del Salado (servicio 2009-2010)

the objective was to analyze the main variables affecting pregnancy rates in 20 cow-calf operations located at the salado river basin (sub-area iv-f) were analyzed during the breeding period 2009- 2010. pregnancy was determined via transrectal palpation from april to june in 107 herds (19529 cows) in the year 2010. cows (primiparous and pluriparous) and heifers of 15 and 27 months of age were evaluated. the number of cows (pregnant, no pregnant), body condition, health status and age of the cows were recorded. the health of the bulls was also evaluated. in conclusion the average pregnancy rate for all categories was 85%. in 23.7% of the cows without presence of diseases, the body condition was equal to or less than 2.5 and the pregnancy rates were 80.7%. herds with a diagnosis of toxic diseases (6%) had lower pregnancy rates, which could be related to the body condition or the direct effect of toxins.