Swine Reproduction. Breeding herds Replacement gilts Replacement gilts Sows Sows Boars Boars.
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Transcript of Swine Reproduction. Breeding herds Replacement gilts Replacement gilts Sows Sows Boars Boars.
Swine Swine Reproduction Reproduction
Breeding herdsBreeding herds
Replacement giltsReplacement gilts Sows Sows BoarsBoars
The boar’s function inThe boar’s function inreproduction:reproduction:
1. Produce spermatozoa1. Produce spermatozoa
2. Introduce sperm into the female2. Introduce sperm into the female
reproductive tract at the properreproductive tract at the proper
timetime
Reproductive Organs ofReproductive Organs ofthe Boarthe Boar
• • TestesTestes
• • EpididymusEpididymus
• • Vas deferensVas deferens
most fluid in most fluid in ejaculateejaculate
• • Vesicular glandsVesicular glands
• • Bulbourethral Bulbourethral glandgland
gel portion of gel portion of ejaculateejaculate
• • UrethraUrethra
• • PenisPenis
Boar’sBoar’sReproductive TractReproductive Tract
BoarsBoars Boars influence conception rate and litter size, and contribute Boars influence conception rate and litter size, and contribute
one-half of the genetic makeup of their daughters. one-half of the genetic makeup of their daughters. Boars lacking fertility or sex drive should be culled as soon as Boars lacking fertility or sex drive should be culled as soon as
possible. possible. For optimal breeding performance, mature boars should not be For optimal breeding performance, mature boars should not be
used for natural service more than twice daily; young boars used for natural service more than twice daily; young boars should be used less often (2-3/week)should be used less often (2-3/week)
The breeding system used should produce the best results in The breeding system used should produce the best results in reproductive performance for the particular physical facilities reproductive performance for the particular physical facilities and management program. and management program.
BoarsBoars Boars should be provided the Boars should be provided the
best environment possible to best environment possible to enhance their breeding enhance their breeding performance. performance.
Thermal stress should be Thermal stress should be prevented. prevented.
Boars should be exposed to Boars should be exposed to females as much as possible to females as much as possible to stimulate male mating stimulate male mating behavior. (20:1)behavior. (20:1)
Slippery floors should be Slippery floors should be avoided in the breeding area. avoided in the breeding area.
Breeding records should be Breeding records should be maintained to determine the maintained to determine the reproductive performance of reproductive performance of boars. boars.
An ejaculate consists of the followingAn ejaculate consists of the followingthree phases:three phases:
1. The first, or pre-sperm phase, which lasts 1 to 51. The first, or pre-sperm phase, which lasts 1 to 5minutes, consists of a watery fluid in which there areminutes, consists of a watery fluid in which there aretapioca-like pellets but no sperm, and comprises 5 totapioca-like pellets but no sperm, and comprises 5 to20% of the ejaculate.20% of the ejaculate.2. The sperm containing phase, which lasts 2 to 52. The sperm containing phase, which lasts 2 to 5minutes, consists of a whitish, uniform fluid whichminutes, consists of a whitish, uniform fluid whichcontains the sperm, and comprises 30 to 50% of thecontains the sperm, and comprises 30 to 50% of theejaculate.ejaculate.3. The last phase, which lasts 3 to 8 minutes contains3. The last phase, which lasts 3 to 8 minutes containsvery few sperm, helps form a gelatinous plug in thevery few sperm, helps form a gelatinous plug in thecervix of the sow, and comprises 40 to 60% of thecervix of the sow, and comprises 40 to 60% of thetotal volume.total volume.
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
fertility as measured by farrowing rates and litter size, fertility as measured by farrowing rates and litter size, gradually decreases as the prevalence of proximal (near gradually decreases as the prevalence of proximal (near
the head) droplets increasethe head) droplets increase
Semen Evaluation:Semen Evaluation:
• • MotilityMotility• • ConcentrationConcentration• • VolumeVolume
TargetTarget::• • Motility:Motility:
60% or better60% or better• • Concentration & Volume:Concentration & Volume:
Determine number ofDetermine number ofinseminations (3-5 billion)inseminations (3-5 billion)
The Sow’s Function inThe Sow’s Function inReproduction:Reproduction:
1. To produce ova1. To produce ova
2. To nourish the developing ova2. To nourish the developing ova
3. To produce piglets3. To produce piglets
4. To produce milk4. To produce milk
Reproductive Organs ofReproductive Organs ofthe Sowthe Sow
1. Ovaries1. Ovaries
2. Oviducts2. Oviducts
3. Uterus3. Uterus
4. Cervix4. Cervix
5. Vagina5. Vagina
6. Vulva6. Vulva
Sow’sSow’sReproductive TractReproductive Tract
www.ansc.purdue.edu/swine/porkpage/repro/sow2.htm
Puberty and breeding Puberty and breeding maturitymaturity
Puberty: 5-7 months (hybrids perform Puberty: 5-7 months (hybrids perform better)better)
Breeding: approx. 7 monthsBreeding: approx. 7 months Polyoestrous (temperature stress!)Polyoestrous (temperature stress!) Length of oestrous cycle 21 daysLength of oestrous cycle 21 days Duration of oestrus 2-3 daysDuration of oestrus 2-3 days Ovulation during the last day of oestrus Ovulation during the last day of oestrus
(back(backpressure test)pressure test)
PGF2A-sensitivity only after day 12PGF2A-sensitivity only after day 12
Breeding factsBreeding facts
Estrus 1-5 days
Heat Period 18-22 days
Gestation 114 days
Breeding age-gilts 7-8 mos.
-boars 7-8 mos.
Breeding weight-gilts 220 lbs.
Temperature effects on Temperature effects on femalefemale
Heat important when affects body temperature - Sources, bothHeat important when affects body temperature - Sources, bothbody and environmentbody and environment
Effect oocyte cause polyploidyEffect oocyte cause polyploidy Prior to breeding is Prior to breeding is greatestgreatest
loss of fertilityloss of fertility
Cause early embryonic mortalityCause early embryonic mortality Especially within the Especially within the firstfirst
7 days past breeding7 days past breeding
Late pregnant sow: Heat stress last week of gestation will greatly Late pregnant sow: Heat stress last week of gestation will greatly increase number of stillborn pigletsincrease number of stillborn piglets
Intensity of estrus may be reducedIntensity of estrus may be reduced
One mechanism, stress causes high glucocorticoids which inhibit One mechanism, stress causes high glucocorticoids which inhibit LH release. Direct effects of heat on gametes is greatest effect!LH release. Direct effects of heat on gametes is greatest effect!
Low temperatures - Reduce intensity of estrusLow temperatures - Reduce intensity of estrus
Species variation in estrous Species variation in estrous cyclecycle
characteristicscharacteristics
Gilt exposure to a mature Gilt exposure to a mature boar boar
Aspects off the vulva,, Aspects off the vulva,, sexualsexual
behavior and fertilitybehavior and fertility
Physical signs to consider for Physical signs to consider for matingmating
Too earlyToo early Vulva heavily red and swollenVulva heavily red and swollenHardly any mucus on vaginal mucosaHardly any mucus on vaginal mucosaNegative back pressure test, only standing Negative back pressure test, only standing reflex in presence of a boarreflex in presence of a boar
In timeIn time Vulva moderately red and swollenVulva moderately red and swollen Vaginal mucosa with mucusVaginal mucosa with mucus Positive back pressure testPositive back pressure test
Too lateToo late No redness or swelling of vulvaNo redness or swelling of vulva Sticky vaginal mucosaSticky vaginal mucosa Negative back pressure test, only Negative back pressure test, only standing reflex in presence of a boarstanding reflex in presence of a boar
2nd mating or AI ‘s are necessary in animals with positive back pressure test 24 h after mating
Gilt standing for "back Gilt standing for "back pressure" testpressure" test
Gilt "in heat", Gilt "in heat",
immobileimmobile Gilt with swollen Gilt with swollen
vulva, secondary vulva, secondary sign of estrus sign of estrus Gilt with swollen vulva,Gilt with swollen vulva,
secondary sign of estrussecondary sign of estrus
Breeding Breeding The The hypothalamushypothalamus located located
at the base of the brain at the base of the brain secretes gonadotropin secretes gonadotropin releasing hormone (GnRH) releasing hormone (GnRH) >>>>> regulates the >>>>> regulates the anterior anterior pituitary glandpituitary gland >>>>> FSH (Follicle >>>>> FSH (Follicle Stimulating Hormone) & LH Stimulating Hormone) & LH (Luteinizing Hormone) into (Luteinizing Hormone) into the blood which stimulates the blood which stimulates >>>>>>> ovarian >>>>>>> ovarian hormones: estrogen and hormones: estrogen and progesterone >>>>> which progesterone >>>>> which in turn regulate the in turn regulate the reproductive process. reproductive process.
Oxytocin is released from the Oxytocin is released from the posterior pituitary gland.posterior pituitary gland.
A.I.A.I.
ReferencesReferences
Sow gestation period???Sow gestation period??? http://www.thepigsite.com/video/single/41/http://www.thepigsite.com/video/single/41/ http://edis.ifas.ufl.edu/an051http://edis.ifas.ufl.edu/an051 http://www.aces.uiuc.edu/vista/html_pubs/http://www.aces.uiuc.edu/vista/html_pubs/
pigs/pigs.htmpigs/pigs.htm http://www.ncsu.edu/project/http://www.ncsu.edu/project/
swine_extension/publications/factsheets/swine_extension/publications/factsheets/812s.htm812s.htm
http://www.ansc.purdue.edu/swine/http://www.ansc.purdue.edu/swine/porkpage/repro/physiol/reppaper.htmporkpage/repro/physiol/reppaper.htm