Traditional Female Assisted Reproductive Technologies

Introduction to ART Procedures for Females

• Focus on enhancing reproductive potential of females.
• Techniques discussed include enhancing superior female genetics and creating a pool of receptive females for breeding.
• Importance of hormone manipulation differs between males and females.

Hormonal Differences Between Males and Females

• Male reproductive techniques do not rely on hormonal manipulation.
• Female hormone levels change daily, making them more susceptible to manipulation.

Diagnostic Testing in Animal Reproduction

• Traditionally, no diagnostic tests other than pregnancy tests were done.
• New diagnostic tests are aimed at identifying superior females rather than those with reproductive issues.
• Understanding traditional techniques can improve production schemes.

Estrus Synchronization: Overview

• Act of manipulating hormones in estrus females to ensure they come into heat simultaneously.
• Key advantages include:
  • Fewer nonproductive days
  • Improved artificial insemination (AI) efficiency
  • Necessary for embryo transfer and in vitro fertilization
  • Produces heavier, more consistent calf crops
• Primary hormones involved: Progestins (progesterone) and Prostaglandins (PGF2α).

Progestins and Their Role

• Progesterone is vital for maintaining pregnancy and regulating estrous cycles.
• High levels of exogenous progesterone can trick the animal's system into thinking it is pregnant.
• When progesterone is removed, the cycle resumes, leading to ovulation.

Role of PGF2α in Estrus Synchronization

• Luteolytic hormone responsible for killing the corpus luteum and stopping progesterone production.
• Active only if PGF2α receptors are present, limiting effectiveness in certain phases of the cycle.
• More cost-effective than progestins but has varied effects.

Application of Hormones in Different Species

• Specific methods need to be consulted based on species.
• Examples include using CIDR devices or injections for progesterone in cattle.

Heat Detection Techniques

• Detection Significance: It’s crucial to know when the female is receptive for successful breeding.
• Different detection methods apply to various species:
  • Sheep: Use of rams aids detection.
  • Pigs: Stance behavior helps identify heat; Lordosis is key.
  • Horses: Requires controlled contact; “teasing” is involved.
  • Cattle: Various behaviors signaling heat; use of markers to identify animals in heat.

Complications of Estrus Detection in Cows

• Factors affecting detection include short estrus period and timing of ovulation post-estrus.
• Best practices include regular checks, ideally at least twice a day.

Superovulation

• Refers to stimulating the growth of multiple follicles.
• Protocol is species-specific, typically requiring high doses of FSH or similar compounds.
• Used in conjunction with embryo transfer or in vitro fertilization.

Embryo Transfer Process

• Requires synchronization of donor and recipient cycles.
• Steps include administration of hormones, natural mating or AI, recovery of embryos, and transferring them to recipients.

Embryo Cryopreservation

• Similar to sperm cryopreservation but tailored for embryos.
• Allows for long-term storage and future use of embryos.

Conclusion

• Understanding and implementing ART techniques is essential for maximizing reproductive efficiency and genetic spread in livestock.