Fertility after artificial insemination using a soybean-based semen extender in sheep

Area of Science:

• Veterinary Reproduction
• Animal Science
• Reproductive Biotechnology

Background:

• Artificial insemination (AI) in sheep is crucial for genetic improvement and efficient breeding programs.
• Traditional semen extenders often contain animal-derived components like egg yolk, raising concerns about pathogen transmission and ethical considerations.
• Developing effective non-animal-derived extenders is essential for safe and sustainable sheep reproduction.

Purpose of the Study:

• To evaluate the fertility of frozen-thawed ram semen using a soybean-based extender (AndroMed) compared to traditional Tris-based extenders with egg yolk or BSA.
• To assess the impact of different semen extenders on pregnancy rates, lambing rates, and prolificacy in Suffolk ewes during the non-breeding season.

Main Methods:

• Suffolk ewes (n=104) were synchronized for estrus using intravaginal sponges and equine chorionic gonadotropin.
• Intrauterine insemination was performed with frozen-thawed ram semen diluted in either AndroMed, Tris-egg yolk, or Tris-BSA extenders.
• Pregnancy and lambing rates were recorded and statistically compared among the treatment groups.

Main Results:

• No significant differences were observed in pregnancy rates among the three semen extenders (AndroMed: 56.7%, Tris-egg yolk: 64.5%, Tris-BSA: 58.6%).
• Lambing rates and prolificacy also showed no significant variations across the different extender groups.
• Fertility outcomes were comparable, indicating the efficacy of the soybean-based extender.

Conclusions:

• The soybean-based AndroMed extender can effectively replace traditional egg yolk-containing extenders for intrauterine insemination with frozen-thawed ram semen.
• AndroMed offers a non-animal derived alternative that maintains fertility, supporting the development of safer and potentially more cost-effective sheep AI protocols.
• This finding has significant implications for the sheep breeding industry, promoting the use of advanced reproductive technologies.