Heat Detection

Technical bulletin
KEYS TO SUCCESS
FTiming is everything –
inseminating too early or
too late not only wastes
semen but can cause
damage to reproductive
tract
FNever inseminate a sow or
gilt when not in “standing
heat” (see over for
detection of standing heat)
FInseminate gilts
immediately after standing
heat is detected and again
12-24 hours later
FInseminate sows 12-24
hours after standing heat
is detected and again
24-36 hours after detection
FAlways wait at least 6
hours between
inseminations
FProper stimulation = strong
uterine contractions =
efficient semen uptake
FHouse boars away from
sows and gilts and limit
“heat detecting” contact to
a maximum of 15 minutes
For more information about
Heat Detection, Artificial
Insemination or other
reproductive question or
products call:
Minitube Canada
1-800-500-7978
Your Reproductive
Experts
Accurate Heat Detection is the #1 Most
Important Factor in AI Success
QUICK FACTS ABOUT SWINE ESTRUS
Definition: Estrus - period of sexual receptivity of the
female to the male during which ovualation takes place
• Female swine display estrus at 18-22 day intervals
throughout the year unless cycling is interrupted by;
- pregnancy
- lactation
- poor nutrition
- disease/physiological/hormonal imbalance
• Gestation is approximately 114 days
• Sows return to estrus 4-7 days after weaning
• Duration of estrus in gilts is approximately 38 hours
• Duration of estrus in sows is approximately 53 hours
Heat Detection and Stimulation
• Should commence from the day of
weaning
• Check for signs of estrus at least once,
and preferably twice each day
• Sows and gilts exhibit signs of heat
in response to a combination of
visual (sight), auditory (sound),
olfactory (smell) and tactile
(touch) stimuli originating from
the boar.
• Use a mature, vocal boar with
strong odour and excessive salivation
• Enable nose to nose, boar to sow
contact
• Provide back pressure
• Limit “heat detection” stimulation
to a maximum of 15 minutes
• Provide boar stimulation and
contact throughout insemination
and for a few minutes after semen
uptake is complete
Technique
• Proper training of technicians
performing AI can dramatically
affect the farrowing rates and litter
sizes
• AI is best performed by a patient,
meticulous individual with proper
training in heat detection
• Performance is optimal if the
technician performs a maximum
of 10 inseminations before taking
a break
• Technician must provide proper
stimulation to each sow and should
limit the number of sows being
inseminated simultaneously
Fall 2006
Technical bulletin
Non-estrus female
1
Signs of Pre-Estrus
• Swollen vulva,
frequently red (picture 2)
• Vocal sounds
• Restless movement
• Looking for boar
• Climbing
• Bar biting
• Riding other females
2
Red swollen vulva Not always a sign of
estrus. Gilts exhibit
red swollen vulva up
to 72 hours prior to
estrus and sows less
than 24.
Standing Response
Stimulation
% of Immobilization
Back Pressure (BP) (picture 7)
48%
BP + Boar Sound (S)
75%
BP + Boar Odour (O)
80%
BP + O + S
90%
BP + O + S + Boar Exposure 97%
Signoret, et al., Pig Production, 1971
Standing response (lordosis)
- Standing quietly when
back pressure is applied and
boar is present.
7
Estrus: Receptivity to the Male
• Off feed, not eating
• Restless movement
• Vaginal Mucus (picture 3)
• Dark red colour on inside
of vulva (picture 4 & 5)
• Elevated temperature
3
• Tail held up (picture 6)
Mucus - Thumb check has
• Quivers
slick feel. Mucus becomes
tacky and stringy shortly
• Ears pricked (picture 7)
after exposure to air.
• Riding other females
• Stands quietly with back
pressure (picture 7)
• Glazed eyes
4
Red interior to
vagina - Appears
when gilts and
sows are in estrus.
5
In gilts, swelling and
red colour diminish.
Vulva once again
becomes red upon
stimulation during
estrus.
6
Tail is held high
as vulva swelling
diminishes.