Lauren Keith

1
Swine Breeding Problem ( 4)

• Lauren Keith
• Claudia Hardie
• Patrick Kusilek
• Liz Seitz

2
Whats the Problem?

• A pig producer is having problems getting her
  gilts and sows to synchronously come into estrus

3
PG600

• Combination of 2 hormones
• PMSG
• Serum of pregnant mares during 1st third of
  pregnancy
• 400 IU/dose
• FSH
• Human Chorionic Gonadotropin (hCG)
• Urine of pregnant women during 1st trimester
• 200 IU/dose
• LH
• 1 dose approximately 6

4
How does it work?
PG600
LH/FSH action on anterior pituitary (calcium
second messenger system)
Follicular growth, increased production of ova,
eventual ovulation
Increase in estrogen levels
Estrus
5
DRUG REGIME

• One shot
• Intramuscularly (in US)
• Can be administered subcutaneously in other parts
  of world? higher success rates
• Estrus should be observed within 4 6 days of
  injection
• 50 60 success rate
• Highly variable
• Do not breed yet (potential problems in farrowing
  rates and litter sizes)
• Most gilts express 2nd estrus approx. 20-21 days
  after 1st induced estrus
• BREED THEN
• What if no estrus is observed within a week?
• Unadvisable to give another shot right away
• Ovulation could have occurred without observed
  estrus
• Another injection could induce new ovulations
  (and a CL) and cause a greater delay in next
  estrus
• A second shot can be administered after 3 weeks
  of anestrus
• Slightly lower success rate ( approx. 50)

6
When can we administer this drug?

• 2 3 weeks before onset of puberty (optimal)
• At least 5-1/2 mos. of age and weigh at least 187
  lbs
• Will only work in gilts that have not yet cycled
• Can be used in newly weaned sows
• Earlier return to estrus and greater number of
  sows mated
• Conflicting reports on resulting pregnancy
• Increased AND decreased litter size
• Slight to no change in farrowing rate
• Further research needed before recommend PG600
  for sow herd
• Why doesnt it work sometimes?
• Season
• Genetics
• Housing
• Nutrition
• Site of injection
• Body condition

7
How can you determine if the treatment regime
worked?

• Estrus displayed within 4-6 days after the
  injection.
• 2nd estrus displayed 20-21 days after the first
  induced estrus.
• Farrowing occurs 3.8 mos. after breeding at
  second estrus.

8
Required Needs to Implement Cycle Management and
Manage Parturition

• Knowledge
• Average/expected age of puberty (determines when
  to administer drugs)
• Records of parturitions/lactations (determines
  when to administer drugs to newly weaned sows)
• Facilities
• Administer shots (IM/Sub-q)
• AI breeding at 2nd estrus
• Time/Labor
• Observe 1st after drug administration
• Observe 2nd estrus
• Care for excess piglets (superovulation)
• Boar
• Exposure for estrus behavioral stimulation

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REFERENCES

• Senger PL. Pathways to Pregnancy and Parturition.
  Second Edition. Washington, 2003.
• University of Illinois Extension. Using PG600 in
  the Swine breeding herd. Repronet Newsletter.
  No1, 1999
• www.pbsanimalhealth.com/swine/pg600.html