Client: Iowa swine producer

1
Client Iowa swine producer

• Problem Getting gilts and sow to synchronously
  come into estrus

2
PG 600

• 400 IU eCG
• 200 IU HCG
• Protein hormones given via IM injection
• FSH and LH-like activities stimulate follicle
  growth and production of estrogen
• Estrogen from follicles stimulate estrus and
  ovulatory surge of GnRH

3
eCG Target Tissue and Effects

• Target Ovaries
• Stimulates follicular development

4
HCG Target Tissue and Effects

• Target Ovaries
• Acts like LH and stimulates follicular growth
• Not enough to trigger ovulation

5
Cellular Response

• eCG and HCG are Protein hormones and use the cAMP
  2nd messenger mechanism of action

6
Feedback Effects

• Stimulates follicle growth
• Follicle produces estradiol and inhibin
• Inhibin inhibits FSH release (negative feedback)
• Positive feedback of estradiol stimulates
  increased FSH release
• Estradiol also stimulates hypothalamus to release
  GnRH causing eventual LH surge

7
Drug Treatment Schedule - Gilts

• Give injection to pre-pubertal gilts
• 5.5 months of age or
• 2-3 weeks before onset of first natural estrus
  (puberty)

• First estrus will appear within 6 days of
  treatment
• Recommend not breeding until 2nd estrus 20-21
  days later
• Better conception rates and pigs/litter

8
Drug Treatment Schedule - Sows

• Give injection to sows which become anestrus even
  after weaning.
• Works well for anestrus sows but of no benefit to
  normal sows that come into estrus after weaning.
• Treated sows ovulate later in estrus than control

9
Producer Advice

• Results of treatment vary drastically farm to
  farm
• At optimal age about 50-65 of gilts show estrus

• Provide adequate boar exposure
• Easy to administer but requires continual
  observation to detect estrus the week following
  injection