Progestagen Use
Various forms of progestagen with different routes of administration has been used to extend the lifespan of the corpus luteum for synchronization in both cycling as well as non-cycling does. The intravaginal sponge has been the treatment of choice for estrus synchronization as well as for out-of-season breeding in goats. These intravaginal sponges usually contain about 45 to 60 milligrams of a synthetic progesterone and are left in place for 8 to 19 days. The most common progestagens used in sponges are fluorogestone acetate (FGA; Cronogest 45) and methyl acetoxy progesterone(MAP; Repromap and Veramix). For the most success, sponges are widely used either in conjunction with pregnant mare serum gonadotropin (PMSG), FSH or prostaglandin to more tightly synchronize and/or induce a superovulatory response. However, under research conditions, sponges impregnated with natural progesterone in higher doses (400-500 mg) have been used and synchrony and fertility similar to that of commercial sponges were achieved. An alternative means of supplying continuous, exogenous progesterone, and the only product FDA-approved for use in goats in the United States, is a controlled internal drug-releasing device (CIDR). This product is in the form of a silicone intravaginal progesterone insert. Administration is similar to that of intravaginal sponges and can be used in conjunction with any of the gonadotropins or prostaglandin listed above. Similar success rates have been obtained.
