摘要：Michoacan brings 2.1% of national GDp. which is 12.5% to agriculture, Livestock is the fourth activity in economic imp.rtance in the State and develop. in 43% of the territory （58,643 km：） using 27% of the p.p.lation economically active. Michoacfin ranks third in national cattle inventory （1,608,523 heads） with fifth p.ace in meat p.oduction （145,221 ton/year）. The p.oduction model is extended cow-breed, subj.ct to season and availability of food （few rains shortage of forage during drought）, with 0.60 p.oduction of breed/cow/year, and a marked traditionalism in the form of p.oduction; also a high dep.ndency to food based on the grazing. The inadequate national p.blic p.licy exp.essed in the p.ternalism has limited the adop.ion of strategies to contribute to the solution of this p.oblem. Therefore this study obj.ctive was to design and validate a strategy to increase the number of cow breeding/cow/year to season rep.oduction p.ogram, based on the use of synthetic p.ogesterone ＂melengestrol acetate＂ （MGA） as a technology available, secure, easy to use, low cost and likely to be adop.able to the traditional model of p.oduction. Work was done in the dry trop.cs in the municip.lities of Churumuco and Tzitzio, Michoacfin State, Mdxico. Used 133 bovine females with crossbreeding Bos indicus, diagnosed as not p.egnant, 6.7 and 6.38 years old resp.ctively for each municip.lity. Oral doses of 0.05 rag/day/cow of MGA during nine days then exp.sed to the p.esence of male. Data were analyzed using analysis of variance of a single way. The results indicate that the delivery rate was 58.33% in Churumuco and 61.86% in Tzitzio. This delivery rate rep.esents an increase of 14%-16% of born p.r year considering that treated females become p.egnant with traditional p.oduction system management. We concluded that the MGA is an ap.rop.iate strategy to the traditional p.oduction of trop.cal dry in MichoacO, n system that increases the rate of births and is likely to be accep.ed desp.te th