Fertility in Cebú × brown Swiss cows treated with prostaglandins, progesterone and eCG

Objective: To evaluate the application of one or two doses prostaglandin F2?(PGF2?), a progestogen on different days estrous cycle and theusage eCG in estrus synchronization fertility Zebu × Brown Swiss cows.Design / methodology approach: The study was based three protocols. firstconsisted treatments: PGI) 26 cows were injected with single 25 mg dose ofPGF2? 10 PGF2? at 14-day interval. Protocol 2consisted NG14) 11 implanted 3 Norgestometon day 7 their NG7) animals received same 14.In protocol all Norgestomet for 9 days, 48 h beforeremoving implant, applied. Once implants removed,they distributed into treatments. (n = 11) without andNorgestomet + (500 IU) 11). Results: times had no influence (p > 0.05) theestrous percentages conception. NG7 achieved 81.8% cows, between 24 36 h, compared to 45.4 % NG14; however, theconception rate lower ? 0.05). synchronized 90.9 ofestrous 36.4 group eCGapplication.Study limitations implications: Transrectal ultrasounds are required assess theovarian structures present time onset protocol.Findings conclusions: Cows that corpus luteum do not require more thanone injection PGF2?, pregnancy percentage increases when isimplanted 14 cycle, addition increasesthe heat after progestogenwithdrawal.