repro 5

CYCLES FOR SPECIES

HORSES

• Cycle Duration: 21 days

• Estrus Duration: 5-7 days

• Ovulation Process:

  • Begins around March on day 5 of the cycle

  • Following ovulation, progesterone levels increase, causing the mare to go out of heat.

• Breeding Season: Cycles occur from early spring through mid-August.

• Prostaglandin Release: When NOT pregnant, prostaglandin peaks on day 13-14 and destroys the corpus luteum (CL).

COWS

• Cycle Duration: 21 days

• Estrus Duration: 18 hours

• Ovulation Process:

  • Occurs POST estrus, indicating that cow ovulation occurs after the estrus phase is completed.

EWE

• Cycle Duration: 17 days

• Ovulation Timing:

  • Occurs 12-18 hours from the start of heat.

• Breeding Characteristics:

  • Short day breeder, indicating a preference for breeding in shorter daylight hours.

MANIPULATION OF ESTRUS

Prostaglandin

• Function:

  • Speeds up the start of estrus.

  • Not effective in sows.

  • Induces abortion in dogs.

LH (Luteinizing Hormone)

• Function:

  • Helps synchronize cycles among females.

  • Induces ovulation in mature follicles.

FSH (Follicle Stimulating Hormone)

• Function:

  • Causes follicular development.

  • Not effective in mares.

Progesterone

• Functions:

  • Reduces GnRH (Gonadotropin-Releasing Hormone) release, impacting the reproductive cycle.

  • Closes the cervix, providing physiological changes during the reproductive cycle.

  • Calms down active and excitable animals, facilitating better management and breeding outcomes.