A Short-Term Altrenogest Treatment Post-weaning Followed by Superovulation Reduces Pregnancy Rates and Embryo...

Area of Science:

• Reproductive Biology
• Animal Science
• Veterinary Medicine

Background:

• Embryo transfer (ET) is a valuable swine industry tool.
• Weaning synchronizes estrus in multiparous sows for embryo donation.
• Superovulation enhances embryo production but often requires multiple donor weanings.

Purpose of the Study:

• To investigate the effects of short-term Altrenogest administration combined with superovulation on reproductive parameters and embryo quality/quantity in weaned multiparous donor sows.

Main Methods:

• Sows received Altrenogest for 4, 7, or 14 days post-weaning before superovulation (eCG and hCG).
• Control groups included superovulated sows without Altrenogest and naturally cycling sows.
• Reproductive parameters, estrus onset, ovarian status, pregnancy, fertilization, and embryo production were evaluated.

Main Results:

• Altrenogest treatments increased ovarian cysts and polycystic ovaries.
• Pregnancy and fertilization rates, and overall embryo production efficiency were negatively affected.
• A high percentage of unfertilized oocytes or degenerated embryos in treated groups were immature oocytes.

Conclusions:

• Short-term Altrenogest administration combined with superovulation negatively impacts swine reproductive efficiency.
• This combination reduces pregnancy and embryo production, with detrimental effects on oocyte quality.
• Optimizing donor availability for swine embryo transfer requires careful consideration of hormonal treatments.