Detailed Explanation of Key Points for Perinatal Management of Sows, a Must-Read for Pig Farmers
What are the key points for perinatal management of sows? You need to know them all!
There is a saying in the pig farming world: "Breeding is the spearhead, farrowing is the key." Farrowing is the greatest stress for a sow, and most piglet deaths also occur during the perinatal period. This shows the importance of perinatal management for sows. Perinatal management refers to the management of sows from the time they are moved onto the farrowing crate until one week after farrowing. The importance of perinatal management can never be overstated.
I. Pre-farrowing Management
1. Feeding amount and feeding method
Sows moved onto the farrowing crate should begin to have their feed reduced 3 days before farrowing, with no less than 2 kg/day being appropriate, as this will reduce the occurrence of constipation and inflammation. If feed is not reduced, after farrowing the sow's abdominal pressure suddenly drops, which may cause agalactia in the sow, thereby affecting the milk production of the lactating sow.
2. Temperature and humidity
The most suitable temperature for sows before farrowing is 18-20°C, and the humidity is 65-75%. If humidity is too high in winter, lime can be spread on damp floors and replaced promptly.
3. Preparations before farrowing
(1) Prepare warming mats, hang infrared lamps inside the warming box, test them and have them ready, and turn on the power 1-2 hours before farrowing.
(2) Prepare clean towels (or cotton cloth), washbasins, paraffin oil, disinfectant (such as 0.1% potassium permanganate), 5% iodine tincture cotton balls, ear notching pliers, tail docking pliers, piglet weighing carts, blood multivitamins, oxytocin, severe mixed infection treatment, farrowing record forms, etc.
4. Signs of impending farrowing in sows
Swollen vulva, sunken tail root, swollen and shiny mammary glands, sometimes a small amount of milk can be squeezed out, restlessness, not eating or lying down quietly, labor pains begin, or sitting like a dog, frequent urination. When the last pair of teats can produce a large amount of thick milk, farrowing will occur in 1-2 hours. When mucus or meconium flows from the vulva, farrowing is imminent.
II. Farrowing, Assisted Farrowing, and Manual Care
1. Sow farrowing
Generally no feed is given on the day of farrowing, but sufficient drinking water should be supplied, and sows should be encouraged to stand up and drink water.
2. Farrowing
After a piglet is born, immediately use a towel to wipe off the mucus from the piglet's mouth and nose, then wipe off the mucus from its body. After the umbilical cord stops pulsating, strip the blood in the umbilical cord toward the piglet's abdomen, then at 3-4 cm from the piglet's body, pinch off the umbilical cord with your fingernails, disinfect the cut end with 5% iodine tincture, and place the piglet in the warming box. Because the most suitable temperature for newborn piglets is 34°C, while for sows it is 18-20°C, this is inherently a contradiction. The ambient temperature of the farrowing room should still be primarily suited to the sow, and the room temperature can be raised to 23°C when farrowing begins. Piglets need a suitable micro-environment temperature, so a warming box or heating pad must be provided.
Generally about 30 minutes after farrowing is completed, the placenta is expelled in two piles. When the last end of the placenta forms a plug, it has been completely expelled. Some sows give birth to piglets from one uterine horn, then expel the placenta from that uterine horn, then give birth to piglets from the other uterine horn, and then expel another pile of placenta. Note: Never pull the placenta hanging from the sow's vulva with your hands, otherwise it will tear the sow's birth canal, causing infection, fever, loss of appetite, and agalactia.
Within 24 hours after piglets are born, routine operations such as ear notching, weighing birth weight and litter weight, iron supplementation, clipping needle teeth, and tail docking should be carried out. Some pseudorabies-positive farms also need to give newborn piglets intranasal immunization with pseudorabies attenuated vaccine. It is worth mentioning that tail docking is best done with electric heated tail docking pliers, because they combine tail docking, disinfection, and hemostasis functions in one, making the operation more convenient.
For piglets showing symptoms of apparent death, rescue should be carried out promptly. Methods: (1) Lift the piglet by its hind legs, and slap the piglet's back with your hand until the piglet makes a crying sound;
(2) Apply alcohol to the piglet's nose to stimulate respiratory movement; the basis for judging an apparently dead pig is a pulsating sensation when pinching the base of the umbilical cord.
3. Correct use of oxytocin:
For multiparous sows, if the first normal piglet is delivered smoothly, observe and care for them normally. If during the subsequent farrowing process the interval between piglets exceeds 45 minutes, 10 units of oxytocin can be injected, but the total injection amount should not exceed 20 units, to avoid causing endocrine disorders. This can greatly shorten farrowing time, reduce the average number of stillbirths per litter, promote the expulsion of the placenta and lochia, help the sow recover appetite as quickly as possible after farrowing, increase weaned piglet weight, and shorten the time to market.
4. Manual assisted farrowing
Normal farrowing in sows produces one piglet every 5-30 minutes, and farrowing is completed in about 2.5-5 hours. If the interval between piglets exceeds 45 minutes, assistance is needed.
The mesh floor behind the sow should be cleaned thoroughly, the assistant's nails should be cut short and filed smooth, and the hands and arms (up to the shoulder) should be washed clean.
Put on long-arm latex gloves, disinfect the gloves, and apply paraffin oil.
Roll your hand into a cone shape, with the palm facing the sow's back. During the interval between the sow's labor pains, slowly insert your arm into the birth canal. If the piglet's hind legs are facing outward, grasp the piglet's hind legs and pull the piglet out; if the piglet's head is facing outward, use your thumb and the other four fingers to hook the piglet's lower jaw and pull the piglet out. If it still cannot be pulled out, a farrowing rope can be used to pull the piglet out; if two piglets are blocking the birth canal side by side, push the inner one back into the uterus and pull out the outer one. Never pull the placenta, umbilical cord, vaginal wall, or the fat on the vaginal wall.
For sows that have undergone assisted farrowing, after farrowing is completed, a large dose of antibiotics should be injected intramuscularly. At the same time, add postpartum health supplement to the feed to prevent postpartum infection, which can effectively prevent diseases such as endometritis and help the sow recover appetite as quickly as possible after farrowing.
Friendly reminder: Supplementing liquid multivitamins one week before farrowing can improve farrowing strength, significantly shorten the farrowing process, and significantly reduce the average number of stillbirths per litter.
5. Manual care during farrowing
According to statistics, 52.1% of pre-weaning piglet deaths are caused by crushing. Most crushing deaths occur within 24 hours after piglet birth. To effectively reduce pre-weaning piglet mortality, dedicated personnel must be assigned to be on duty during sow farrowing.
To reduce the burden of manual care and facilitate centralized management of sows and postnatal piglets after farrowing, cloprostenol can be injected intramuscularly on the morning of day 114 of gestation, which can control most pregnant sows to farrow during the daytime of the next day.
III. Lactation
1. Feeding amount
Sows begin to be fed the day after farrowing. On the first day of feeding, feed 2 kg. The feeding amount should increase at a rate of 0.5-0.8 kg per day, reaching the maximum amount by the seventh day. For sows normally nursing more than 10 piglets, in order to increase the sow's milk production, the maximum feed intake of the pig must always be maintained. The feeding amount is usually determined based on the number of live-born piglets. Individual feed intake standard feed amount = 2 kg + 0.5 x number of piglets N.
2. Feeding method
Most pig farms currently use pelleted feed. If labor is sufficient, it is best to use wet mixed feed. Compared with directly feeding dry powder feed, feeding wet mixed feed has the advantages of better palatability and reduced dust content in the pig house air, thereby reducing the incidence of respiratory diseases in the pig herd. Some pig farms abroad have even achieved the use of liquid feeding lines for sows in the farrowing room, which is even more helpful for increasing the feed intake of lactating sows.