Embryo Transfer in Cattle Production

Jul 15, 2024

Embryo Transfer in Cattle Production

Introduction

  • Primary goal: Raise as many superior calves as possible
  • Challenge: Superior cows can only have one calf per year
  • Solution: Embryo transfer to produce several calves from the same cow in one crop

Embryo Transfer Concept

  • Definition: Removal of early embryos from a donor female and implantation into recipients
  • Advantages:
    • Better use of superior females
    • Increased offspring: average cows produce ~7-10 calves, but viable embryos could yield more
    • Allows cows to produce multiple offspring per year through superovulation and embryo transfer
    • Faster progeny testing for genetic evaluation
    • Economical for export and prevention of disease spread
    • Helps in increasing population of rare breeds

Process of Embryo Transfer

  • Super ovulation: Inducing donor cow to produce multiple eggs
  • Hormones used: FSH (follicle stimulating hormone)
  • Artificial insemination: Done 12 hours post standing estrus using 2 straws of semen
  • Collection: Embryos collected 7 days after estrus using a flushing technique

Steps in Embryo Collection

  1. Anesthesia: Administered epidural anesthesia to donor cow
  2. Preparation: Cleaning of the vulva area and proper sanitation
  3. Catheter insertion: Through cervix into the uterus, inflating a balloon to secure
  4. Flushing: Flushing fluid in and out to collect embryos from uterus to filter
  5. Laboratory work: Embryos identified under a microscope, washed, and prepared for transfer or freezing

Embryo Freezing Process

  • Solution: 10% glycerol for freezing
  • Steps:
    1. Draw solution into syringes and filter into wells
    2. Label straws with breed code, registration number, straw number
    3. Wash embryos carefully in solution to remove debris
    4. Move embryos through successive wells for thorough cleaning
    5. Load embryos into straws with air bands and seal them
    6. Use program to gradually freeze embryos from -7°C to -36°C
    7. Label canes and goblets, seed straws with ice crystals

Key Terms and Definitions

  • Estrus: Female receptivity for breeding (~6-14 hours, every 21 days)
  • Estrus cycle: 21-day cycle from one estrus to next
  • Gametes: Male/female germ cells (egg or sperm)
  • Conceptus: Fertilized egg, embryo, or fetus
  • Gestation: Pregnancy period
  • Parturition: Process of giving birth

Conclusion

  • Embryo transfer: A valuable tool for improving cattle genetics and increasing calf production
  • Careful selection: Donor and recipient cows should be selected based on genetic and physical soundness
  • Future: Potential wider use in commercial breeding, similar to artificial insemination