Detection of standing heat is the most critical component of a successful swine breeding program. Widespread adoption of artificial insemination (Ai) in the pig industry has shifted the responsibility of detecting estrus from boar to pig farmers themselves.
Accurate and consistent detection of heat is necessary to ensure insemination occurs exactly the time of ovulation or standing HEAT. (when the sow/gilt is receptive and will stand for mating/service).
TYPICAL HEAT SIGNS:
Estrus or heat is defined as a period of sexual receptivity and ovulation during which the female will accept the male and is capable of conceiving.
- First heat in gilts is at 170-210 days.
Skip the first and the second heat in gilts and mate them on the third. At this stage, they would have grown to maturity, desired weight, etc, ready to manage pregnancy without complications.
Administer farrowsure at 24 weeks and a booster at 27 weeks before mating.
- while for sows ovulation begins within 3-7 days after weaning. Provide 10 to 15 minutes per day of full boar contact for the first three days after weaning.
- Give a dose of litterguard to all pregnant pigs on the 100th day into pregnancy.
- Estrus in gilts lasts for 40 hours while mature sows 55 hours.
- Typical ovulation occurs usually 30-40 hours after onset of estrus.
PHYSICAL SIGNS OF HEAT. The proestrus period occurs just before oestrus and lasts about a day.
- Thoroughly check the back end: swollen, red vulva (more notable in gilts than sows), watery discharge from vulva, clitoris flat and pale pink, becoming more prominent.
- Activity: restless, climb up gates and walls, mount other females but do not stand themselves, increased interest in the boar.
- Standing reflex (the best indicator):
Check twice daily by apply pressure to the back and flank. Do this at the same time with a boar presence. Receptive females will stand rigid and ears often prick up.
Take females to the boar in a designated pen.
In a case where you use Artificial insemination, use teaser boars to stimulate gilts/sows to full estrus or standing heat by allowing them roam around designated sow pens. But must not be left in with sows awaiting Ai. Pheromones (odours) produced by active and chatty boars are the most potent and effective means of inducing the standing reflex in females.
Records are important: note tag number, date and time of proestrus, date and time of oestrus and standing heat.
Develop a coloured marker system like above to show clearly the status of each female.
