Cost $4.70/head Two Injections of PGF  Advantages – Useful for detection of estrus in heifers and cows – Tighter synchrony than one injection method – Can use fixed insemination time after 2nd injection  Limitations – Females must have functional CL – Length of estrus detection – Administration of PGF will cause abortion in pregnant animals Cost $8.00/head MGA and Prostaglandin  Advantages – Proven system for heifers – Inexpensive method – Can hasten cyclicity in anestrous females  Limitations – Length of program – Must have appropriate feeding space to allow efficient consumption – Estrus synchronization may be variable – Must ensure uniform daily consumption of feed supplement prior to and during oral administration of MGA Cost $14.00/head CIDR  Advantages – Useful for detection of estrus in heifers and cows – Induces cyclicity in a percentage of anestrous cattle – High pregnancy rates  Limitations – Possible retention failure of CIDR – Cost per treatment may be higher than other methods – An additional day of processing for hormone treatment would be required to facilitate fixed time AI Cost $9.00/head Cost $9.00/head GnRH  Advantages – Higher and tighter rate of estrus synchrony compared to PGF protocols – Allows for estrus detection or timed AI  Limitations – Higher cost due to hormone injections – Increase of time and labor – Not recommended for use in heifers Synchronization in the Mare Products used: Equimate, Estrumate, Lutalyse      When administered in diestrus, expect ovulation in 7-12 days If 30-35mm follicle is present, expect ovulation in 2-4 days Will only work when fully functional CL is present “short cycling” refers to restarting the estrous cycle early Prostaglandin should be given after day 6 hCG can be given to mares resulting in immediate ovulation Synchronization in the Sow Prostaglandin will not cause CL regression until day 12 of cycle because LH binds to luteal cell receptor with strong affinity following ovulation and is not released until day 12. Repeated injections over two to three days will regress CL sooner, but is not practical.  Common progestins will synchronize estrus but cause ovarian cysts  Regumate has been found to be effective  Noncycling gilts can be synchronized with P.G. 600 (400 IU eCG and 200 IU hCG) Synchronization in the Ewe Most common protocols use either use prostaglandins or CIDR