Parturition (Farrowing) in the pig

assuming farrowing at 115 days

Time	Event
110 days	Foetal production of corticosteroids
111	Progressive swelling of vulva
	Vulva becomes redder
	Mammary glands develop
113	Individual mammary glands easily visible
114	Sow becomes restless
	Nest making starts
	Sow stops eating
	Milk can be expressed from nipple
115	Sow lies down with periods of restlessness with clawing and chomping of bedding materials
	60-75% of sows farrow at night
-1 hour	Sow settles down in lateral recumbancy
	Intermittent straining and paddling of legs
-10 minutes	Passage of small quantity of foetal fluid
	Marked twitching of tail
	Pain and abdominal effort/straining Leg movement in time with contractions
0	Passage of first piglet
0-3 hours	Sow more relaxed
	Passage of piglets every 10-20 minutes
	Gilts may be restless after 2-3 piglets
	Piglets born within 3 hours of all piglets
After last piglet	Sow stands and urinates
	Sow lies down quietly suckles
4 hours later 8 hours max	Placental mass passed
	The sow does little to assist her piglets
	There is no sure way of knowing a sow has passed all her piglets and placenta. Watch sow behaviour for the next 24 hours

Induction of farrowing

Injection of PGF_2a on day 112-113 results in parturition 28 hours later.

50 to 60% of pigs will farrow on the following day after an injection at 7.00am the previous day, but note 20-25% will not.

Hormonal Assistance in farrowing

Oxytocin 5-10 IU intramuscular. More than 10 IU results in uterine spasm.

Submucosal intralabial injection only requires 2.5 IU oxytocin.