the polymeric implant is obtained from a renewable source , comprising a body formed by at least one biodegradable polymer selected from the group consisting of polyhydroxyalcanoates and copolymers thereof , said body incorporating , in its micro - structure , an active ingredient in a sufficient quantity to control at least one oestrus cycle of mammal animals . the invention further refers to a process for obtaining a polymeric implant comprising the steps of : mixing progesterone or progestogen , at least one polymer of the group of phas , one polymeric additive defined by poly , and at least one dispersant additive and / or solvent , to obtain a colloidal solution ; evaporating the solvent of the colloidal solution , and forming a paste with the components dispersed therein ; drying the paste to remove the residual solvents and control the granulometry of the polymer composite ; extruding the polymeric composite and moulding the latter in an implant body .