"Sincronización de la ovulación y el ciclo inducido por el efecto ""macho"" mediante la administración de progesterona por vía intravaginal en cabras en período de anestro estacional"

Abstract

Classical hormonal treatments for the induction and synchronization of oestrus and ovulation joined the fixed-time artificial insemination in goats use progestogens and eCG. Some alternatives methods are based on the stimulus by the presence of males (buck/male effect) and the use of prostaglandin F2 α or its analogues like the IMA. PRO2® method. In these methods, the administration of a low dose of progesterone or progestin, at the time of the introduction of males, is an effective way to avoid the presence of poor quality corpora lutea that generates short cycles, reaching a first induced cycle with an appropiate luteal function. With IMA- PRO2®, females are subjected to the male effect plus a single intramuscular dose of 25 mg of progesterone in olive oil at the time of male introduction, achieving good pregnancy rates after a single dose of cloprostenol and systematic timed AI. However European directives have set new restrictions, the use of steroids in food-producing animals is banned and progesterone or progestogens are limited only in an intravaginal use. Four experiments were designed in order to develop an intravaginal way of progesterone administration that could be used under field conditions with similar fertility rates to the IMA- PRO2® method ...