Heat (oestrus) in the sow
The female pig (sow) is ready to breed (reaches puberty) at 5
months of age and will show signs of being in heat. Some slow growing
types and animals which are underfed will be older when they reach
puberty.
The sow will come into heat every 3 weeks throughout the year if she is not mated. |
Learning objectives
After studying this unit you should know:
1 When a female pig is ready for breeding.
2 How often the pig comes into heat.
3 The signs of heat in the pig.
4 How to make the pig come into heat.
When is the sow ready for breeding?
Most breeds of pig reach puberty at 5 months of age but some,
e.g. the Chinese pig, come into heat for the first time at 3 months of
age when they have enough good feed and water.
The pig should not be used for breeding when she comes into heat
for the first time. It is wiser to allow her to grow for another month
before using her for breeding. She will then be better able to carry and
suckle a good litter of young. Only sows with 14 teats should be used
for breeding so that all her litter can feed.
If the pig is not mated she will come into heat every 21 days, providing she has enough feed and water.
Signs of heat
The female pig coming into heat is restless and may not eat. The
vulva becomes pink and swollen. When the pig is pressed hard with the
hands on either side of her back she will stand still, showing she is
ready to accept the male.
Signs of heat
The sow will be in heat for 8 to 36 hours.
How to bring the sow into heat
Healthy, well fed sows can be brought into heat so that breeding can be controlled.
Putting a sow which is in heat in with those which are not in
heat will make some of the latter come into heat. A better method is to
pen sows next to a boa so that they can see and smell him. The sows will
come into heat especially if the boar is old and smelly.
Remember that failure to come into heat can be the result of poor or too little feed or a health problem in the sow.