Common signs of heat
- The sow's vulva is flushed (reddish) and swollen two or three days before standing heat.
- The vaginal discharge is watery.
- The vaginal discharge is watery.
- The sow is restless.
- As the sow comes into heat, she will mount other pigs or will allow other pigs to mount her. She will move away unless she is in full "standing heat".
- The sow stands still when she feels pressure on her back.
Heat lasts about 24 hours. After that, the sow will not stand still for the boar. Some sows bleed from their vulva following a heat Period.
How to induce heat
After farrowing, a sow may be slow to come into heat Here are a few methods used by farmers to induce heat.
- Gently stroke the sow's vagina with a freshly cut papaya stalk every morning for 3-5 days.
- Spray the sow's (or gilt's) pen with boar urine every morning for 3-5 days.
- Grind 1 kg of fresh or dried lotus (Semen nelumbinis) seeds. Mix with 20 kg of dry feed. Feed to the sow twice a day for 5-7 days.
- Bring the sow to the boar, or place the sow in a pen next to the boar.
During her 24-hour heat period, a sow should be mated 2 times at approximately 12-hour intervals. Do not mate animals during the hot time of day.
Young boars may need assistance in lining up their mate. Make sure your hands and wrists are clean and your fingernails are trimmed.
Pigs mate slowly. The boar may take a minute or more to reach the point of ejaculation.
To improve conception
- Crush 1 kg of Semen nelumbinis (lotus) seed and mix with the sow's feed. Give 2 times per day for 3-5 days.
- Fat sows may have difficulty conceiving. Therefore, if a sow is too fat, reduce her feed.
Reasons for not conceiving
- The sow is too fat.
- It is the animal's first heat cycle.
- The boar is too young.
- The boar is overworked (used for more than five matings a week).
If a sow does not show signs of heat three weeks after mating, then it is very likely that she is pregnant.
Care during pregnancy
- Separate pregnant sows from other animals.
- Protect pregnant sows from high temperatures.
- Do not transport a pregnant sow.
- Until the final stages of pregnancy, exercise is good for pregnant sows. Give the sow space to walk in.
Feed for pregnant sows
- Provide a good supply of clean drinking water.
- If you are feeding a concentrate ration, gradually reduce the ration one week before farrowing.
- Make green forage available to the pregnant sow.
- Throughout the pregnancy, feed pregnant sows rice water (the
water left after cooking rice).
(Thailand. 1, 2)
- Add Amaranthus gracilis and Amararanthus spinosus to the pregnant sow's feed. Feed a ration of 2 percent of the sow's body weight per day throughout pregnancy.(Thailand. 1, 2, 3, 4)
- Feed the fresh leaves and stems of water spinach or swamp cabbage (Ipomoea aquatica) daily to pregnant sows. (Thailand. 1, 2, 3, 4)
- Feed sows a soup made of rice and one eel once each day for 7 days before birth. This is said to make farrowing easier. (Cambodia. 1, 2, 3, 4)
- Feed 3 to 5 lombrice (round earthworms) every day throughout pregnancy. Earthworms are a good source of protein. Some farmers also think that the earthworm's long, thin shape helps ease the birthing process. (Cambodia. 1, 2, 3, 4)
- If the sow is constipated during pregnancy, feed large amounts of rice bran or sweet potato leaves as a laxative. See Constipation, page 13.(Philippines. 1, 2, 3, 4)
A sow needs a special place for farrowing (birthing). One week before the animal is expected to farrow, put it in the farrowing pen so it can adjust to the area. Provide a separate farrowing pen for each animal.
A farrowing pen should be 2 m by 2.5 m in size. The pen should have piglet guard rails along the sides. These can be planks or poles 20 to 25 cm off the floor, reaching about 30 cm from the walls. Guard rails will help prevent piglets from being crushed by the sow.
- Disinfect the farrowing each time before it is used. To disinfect, pour boiling water over the entire pen.
- Allow proper ventilation in the pen, but make sure there are no drafts or winds.
- Keep the birthing area clean and dry.
- Provide sufficient drinking water.
- Scrub the whole body of the sow with clean water and a clean cloth. One day before farrowing, brush the animal to remove external parasites. This will help protect the piglets from parasites.
If no special pen is provided, the sow will follow her mothering instincts and prepare her own farrowing area. She will dig a shallow pit in the ground as a farrowing place.
In tribal areas of northern Thailand, it is seen as bad luck for a sow to farrow inside the village. In such cases, the sow and piglets are killed. To avoid this, sows are encouraged to farrow in an area outside the village.
Pigs should have a place to go where they are protected from the elements. A simple open shelter can be constructed from sticks and thatch.
Bedding materials commonly used
- Chopped hay or straw.
- Coarse sawdust.
- Dried banana leaves.
- Jute or burlap sacks.
Birthing In a normal birth, piglets begin arriving within 30 minutes of the first labor signs. Normally, they are born at intervals of 10 to 15 minutes. All piglets are usually born within 3 hours. The placenta (afterbirth) should follow within 20 to 30 minutes.
Symptoms of birthing difficulties
- The sow makes an effort to expel the piglets, but no piglet will come out.
- Hard stool is putting pressure on the birth canal.
- Piglet is in an abnormal position.
- Sow is too fat and has a narrow birth canal.
Prevention Ensuring that the animal is in good condition is the best way to avoid problems at farrowing time. See the section on Feed for pregnant sows, page 59.
What to do if a piglet is stuck
If a piglet is stuck in the birth canal, you will have to help. First, trim your fingernails, wash your hands and arms well with soap and apply a lubricant of vegetable oil. Gently slide your hand into the sow's vagina and feel for the piglet.
- If it is a large piglet, pull it gently but firmly in time with the sow's pushing.
- If the piglet is stuck sideways, push it back in and try to turn it so it comes out straight (head first or hind first).
- If you cannot correct the problem, call a professional (a local expert, respected healer or veterinarian).
Sometimes, the placenta will stay inside the sow after farrowing. If this happens you can try one of the simple treatments below. See also the section on Pregnancy and birthing in Ruminants for more remedies.
- Grind together 7 dry garlic cloves, 7 dry black pepper seeds, 7 slices (5 mm thick) of fresh ginger rhizome and 7 upper leaflets of 7 cotton plants. Grind the ingredients together in 1/2 cup of whisky (do not strain) and give as a drench. If 1 drench does not work, repeat the treatment.(Northern Thailand. 1, 2, 3, 4)
- Grind 3 leaves of betel (Piper betle) and mix with 1 cup of water. Strain and give as a drench 1 time. If 1 drench does not produce results, drench again at 2 hour intervals.(Cambodia. 1, 2, 3, 4)