Comparing CIDR with progesterone injections and eCG with human recombinant FSH for synchronizing estrous cycle in...

Area of Science:

• Veterinary Medicine
• Reproductive Biology
• Animal Science

Background:

• Estrus synchronization in sheep aims to shorten programs and eliminate intravaginal devices.
• There is a global need for safe, cost-effective gonadotropin alternatives to eCG.

Purpose of the Study:

• To investigate the efficacy of human recombinant FSH (hrFSH) as a replacement for eCG.
• To evaluate progesterone injections as an alternative to CIDR for estrus synchronization in ewes.

Main Methods:

• 170 Assaf and Lacaune ewes were synchronized using either 6-day progesterone injections or 14-day CIDR.
• Ewes received GnRH analogue, progesterone injections, prostaglandin F2α, and either hrFSH or eCG.
• Estrus was detected, and rams were introduced for breeding.

Main Results:

• No significant differences were observed in lambing rates, prolificacy, or fecundity between the CIDR and progesterone injection groups.
• Reproductive parameters were comparable between ewes treated with eCG and those treated with hrFSH.
• The 6-day progesterone injection protocol yielded results similar to the 14-day CIDR program.

Conclusions:

• A 6-day progesterone injection protocol is a viable alternative to the 14-day CIDR program for estrus synchronization in ewes.
• Human recombinant FSH (hrFSH) can effectively replace eCG in estrus synchronization protocols for sheep.
• These findings offer a shorter, potentially more cost-effective approach to sheep breeding management.