Naturally-occurring PGF 2 a as the tromethamine salt (Lutalyse, Upjohn; ProstaMate, Phoenix Scientific), and synthetic analogs of PGF 2 a such as cloprostenol (Estrumate, Haver), are sold for synchronization of estrus in nonlactating cattle ( Figure 4-46 ) and horses. The cost of a single-injection prostaglandin program is less than that of a progestin system and not as laborious. Animals must be in diestrus to respond to PGF 2 a (the young CL is insensitive to treatment), return to estrus is somewhat variable (semen is wasted if breeding-by-appointment), and treatment of pregnant females can cause abortion. Porcine CL will not respond to PGF 2 a until about Day 12 of the estrous cycle. Gonadotropin-releasing hormone (to induce ovulation and CL formation) is being used in cattle in combination with PGF 2 a (eg., SelectSynch: GnRH + PGF 2 a [Day 7]; Ov/CoSynch: GnRH + PGF 2 a [Day 7] + GnRH [Day 9]).
If you believe you are ready for one of the following cycles you will have many cycles under your belt, supplemented with numerous anabolic steroids , 5 is a good number and have learned how to not only have successful cycles but ones in-which side-effects are controlled. Further, to be ready for an advanced cycle you will be one who is able to maintain more gains after a cycle than you lose. Some gains will always be lost after a cycle is complete, this is a given but maintaining a majority of your gains is possible. If this is not possible for you then you need to reexamine your use, your diet and perhaps even your training.