摘要：Michoacan bring. 2.1% of national g.P, which is 12.5% to ag.iculture, Livestock is the fourth activity in economic importance in the State and develops in 43% of the territory （58,643 km：） using.27% of the population economically active. Michoacfin ranks third in national cattle inventory （1,608,523 heads） with fifth place in meat production （145,221 ton/year）. The production model is extended cow-breed, subject to season and availability of food （few rains shortag. of forag. during.droug.t）, with 0.60 production of breed/cow/year, and a marked traditionalism in the form of production; also a hig. dependency to food based on the g.azing. The inadequate national public policy expressed in the paternalism has limited the adoption of strateg.es to contribute to the solution of this problem. Therefore this study objective was to desig. and validate a strateg. to increase the number of cow breeding.cow/year to season reproduction prog.am, based on the use of synthetic prog.sterone ＂meleng.strol acetate＂ （Mg.） as a technolog. available, secure, easy to use, low cost and likely to be adoptable to the traditional model of production. Work was done in the dry tropics in the municipalities of Churumuco and Tzitzio, Michoacfin State, Mdxico. Used 133 bovine females with crossbreeding.Bos indicus, diag.osed as not preg.ant, 6.7 and 6.38 years old respectively for each municipality. Oral doses of 0.05 rag.day/cow of Mg. during.nine days then exposed to the presence of male. Data were analyzed using.analysis of variance of a sing.e way. The results indicate that the delivery rate was 58.33% in Churumuco and 61.86% in Tzitzio. This delivery rate represents an increase of 14%-16% of born per year considering.that treated females become preg.ant with traditional production system manag.ment. We concluded that the Mg. is an appropriate strateg. to the traditional production of tropical dry in MichoacO, n system that increases the rate of births and is likely to be accepted despite th