Swine Reproduction

1
Swine Reproduction
2
Breeding herds

• Replacement gilts
• Sows
• Boars

3
The boars function inreproduction

• 1. Produce spermatozoa
• 2. Introduce sperm into the female
• reproductive tract at the proper
• time

4
Reproductive Organs ofthe Boar

• Testes
• Epididymus
• Vas deferens
• most fluid in ejaculate
• Vesicular glands

• Bulbourethral gland
• gel portion of ejaculate
• Urethra
• Penis

5
BoarsReproductive Tract
6
(No Transcript)
7
Boars

• Boars influence conception rate and litter size,
  and contribute one-half of the genetic makeup of
  their daughters.
• Boars lacking fertility or sex drive should be
  culled as soon as possible.
• For optimal breeding performance, mature boars
  should not be used for natural service more than
  twice daily young boars should be used less
  often (2-3/week)
• The breeding system used should produce the best
  results in reproductive performance for the
  particular physical facilities and management
  program.

8
Boars

• Boars should be provided the best environment
  possible to enhance their breeding performance.
• Thermal stress should be prevented.
• Boars should be exposed to females as much as
  possible to stimulate male mating behavior.
  (201)
• Slippery floors should be avoided in the breeding
  area.
• Breeding records should be maintained to
  determine the reproductive performance of boars.

9
An ejaculate consists of the followingthree
phases
The spermatogenic cycle in the boar is 35 days,
with 10 days for epididymal transport. Thus 45
days are required from the start of production to
ejaculation of sperm

• 1. The first, or pre-sperm phase, which lasts 1
  to 5
• minutes, consists of a watery fluid in which
  there are
• tapioca-like pellets but no sperm, and comprises
  5 to
• 20 of the ejaculate.
• 2. The sperm containing phase, which lasts 2 to 5
• minutes, consists of a whitish, uniform fluid
  which
• contains the sperm, and comprises 30 to 50 of
  the
• ejaculate.
• 3. The last phase, which lasts 3 to 8 minutes
  contains
• very few sperm, helps form a gelatinous plug in
  the
• cervix of the sow, and comprises 40 to 60 of the
• total volume.

10
fertility as measured by farrowing rates and
litter size, gradually decreases as the
prevalence of proximal (near the head) droplets
increase
11
(No Transcript)
12
Semen Evaluation

• Motility
• Concentration
• Volume
• Target
• Motility
• 60 or better
• Concentration Volume
• Determine number of
• inseminations (3-5 billion)

13
The Sows Function inReproduction

• 1. To produce ova
• 2. To nourish the developing ova
• 3. To produce piglets
• 4. To produce milk

14
Reproductive Organs ofthe Sow

• 1. Ovaries
• 2. Oviducts
• 3. Uterus
• 4. Cervix
• 5. Vagina
• 6. Vulva

15
SowsReproductive Tract
www.ansc.purdue.edu/swine/porkpage/repro/sow2.htm
16
(No Transcript)
17
Puberty and breeding maturity

• Puberty 5-7 months (hybrids perform better)
• Breeding approx. 7 months
• Polyoestrous (temperature stress!)
• Length of oestrous cycle 21 days
• Duration of oestrus 2-3 days
• Ovulation during the last day of oestrus (back
• pressure test)
• PGF2A-sensitivity only after day 12

18
Breeding facts
Estrus Estrus 1-5 days
Heat Period Heat Period 18-22 days
Gestation Gestation 114 days
Breeding age-gilts Breeding age-gilts 7-8 mos.
-boars 7-8 mos.
Breeding weight-gilts Breeding weight-gilts 220 lbs.
19
Temperature effects on female

• Heat important when affects body temperature -
  Sources, both
• body and environment
• Effect oocyte cause polyploidy Prior to
  breeding is greatest
• loss of fertility
• Cause early embryonic mortality Especially
  within the first
• 7 days past breeding
• Late pregnant sow Heat stress last week of
  gestation will greatly increase number of
  stillborn piglets
• Intensity of estrus may be reduced
• One mechanism, stress causes high
  glucocorticoids which inhibit LH release. Direct
  effects of heat on gametes is greatest effect!
• Low temperatures - Reduce intensity of estrus

20
Species variation in estrous cyclecharacteristics

21
Gilt exposure to a mature boar
22
Aspects off the vulva,, sexualbehavior and
fertility
23
Physical signs to consider for mating
Too early Vulva heavily red and swollen Hardly any mucus on vaginal mucosa Negative back pressure test, only standing reflex in presence of a boar
In time Vulva moderately red and swollen Vaginal mucosa with mucus Positive back pressure test
Too late No redness or swelling of vulva Sticky vaginal mucosa Negative back pressure test, only standing reflex in presence of a boar
2nd mating or AI s are necessary in animals with
positive back pressure test 24 h after mating
24
Gilt standing for "back pressure" test
25
Gilt "in heat", immobile

• Gilt with swollen vulva, secondary sign of estrus

• Gilt with swollen vulva,
• secondary sign of estrus

26
Breeding

• The hypothalamus located at the base of the brain
  secretes gonadotropin releasing hormone (GnRH)
  gtgtgtgtgt regulates the anterior pituitary gland
  gtgtgtgtgt FSH (Follicle Stimulating Hormone) LH
  (Luteinizing Hormone) into the blood which
  stimulates gtgtgtgtgtgtgt ovarian hormones estrogen and
  progesterone gtgtgtgtgt which in turn regulate the
  reproductive process.
• Oxytocin is released from the posterior pituitary
  gland.

27
A.I.
28
References

• Sow gestation period???
• http//www.thepigsite.com/video/single/41/
• http//edis.ifas.ufl.edu/an051
• http//www.aces.uiuc.edu/vista/html_pubs/pigs/pigs
  .htm
• http//www.ncsu.edu/project/swine_extension/public
  ations/factsheets/812s.htm
• http//www.ansc.purdue.edu/swine/porkpage/repro/ph
  ysiol/reppaper.htm