1. Causes of sow dystocia
The causes of sow dystocia are complicated, but in production practice, some people divide it into maternal dystocia and fetal dystocia according to the types of dystocia. The incidence of maternal dystocia is about twice that of fetal dystocia, of which dystocia caused by uterine atony accounts for about 4%, followed by dystocia caused by narrow birth canal. Among fetal dystocia, dystocia caused by sitting, twins entering the pelvic cavity at the same time, fetal head bending down and fetal oversize is the most common. Dystocia caused by fetal malformation often occurs.
1.1 maternal dystocia
1.1.1 dystocia with weak fertility
sow's food intake is large, which leads to sow's obesity and weak uterine contraction during delivery. Sows are malnourished and lack of exercise, and their abdominal muscles are weak during delivery. There are also sows who are weak, have high parity or have many litters. Due to fatigue, the uterus is weak and the fetus cannot be discharged from the birth canal, causing dystocia.
1.1.2 Obstruction due to narrow birth canal
is more common in primiparous sows. Due to premature mating of reserve sows, the pelvis is underdeveloped, and the sow is still in the growth and development stage after mating and pregnancy. The pelvic orifice is too small. Although the sow undergoes intense uterine contraction, the fetus can't discharge from the uterine orifice, resulting in dystocia
1.1.3 dysuria due to bladder accumulation or intestinal obstruction
during delivery.
1.1.4 stress dystocia caused by external stimuli
It is more common in primiparous and timid sows. Due to the strong external stimuli such as sudden fright or restless delivery environment, the uterus can't contract normally, causing dystocia.
1.1.5 abnormal birth canal and diseases of sows can also cause dystocia.
1.2 Fetal dystocia
1.2.1 Fetal hyperdystocia
Incorrect mating, small number of piglets, too large fetus or too much feed for the sow in the later stage, which leads to the over-sized fetus.
1.2.2 Dystocia due to fetal malposition
It is more common in dystocia caused by fetal malposition in the birth canal.
1.2.3 Abnormal fetal dystocia Fetal malformation can not pass through the birth canal smoothly, resulting in dystocia.
1.2.4 stillbirth dystocia
The fetus died in the mother's body for a long time, causing fetal edema and bloating, resulting in dystocia.
1.2.5 Two fetuses enter the birth canal at the same time, causing dystocia.
1.3 Other reasons
1.3.1 Improper medication, such as premature use of uterine contractions.
1.3.2 premature delivery, frequent delivery, rude operation, too little and too much lubricant used in the birth canal, etc., lead to vaginal edema.
2. Treatment of sow dystocia
2.1 Drug induced labor
After the complete and smooth birth canal is diagnosed, drug induced labor is used. Oxytocin, or oxytocin, is the first choice, and it is suggested to inject oxytocin < P > 3 ~ 5IU intramuscular or subcutaneous every 2 ~ 3 min. In order to improve the efficacy of oxytocin, estrogen can be used selectively, that is, 1 ~ 2 mg of estradiol or other estrogen preparations can be injected intramuscularly before oxytocin is used.
2.2 artificial midwifery
2.2.1 matters needing attention in artificial midwifery
generally, find a worker with small hands, cut short the nails, remove the dirt on the edges of the nails and polish the edges of the nails, soak the palms, arms and sow's vulva with .1% potassium permanganate, coat the palms and arms with soap or paraffin oil, and put the five fingers together in a conical shape and slowly rotate into the sow's birth canal. The midwifery should not be pulled too hard, so as not to damage the sow's birth canal or cause the birth canal to prolapse.
2.2.2 Method of artificial midwifery
Hands-free pulling method: The midwife's arm slowly extends into the sow's birth canal to find out the fetal position of the piglets. When the piglets are alive, the four fingers catch the ears of the piglets and slowly pull, or the thumb and middle finger can be used to grab the piglet's orbit or the thumb and forefinger can be used to tighten the piglet's jaw gap to slowly pull. When the piglets are upside down, you can slowly pull them out by holding the hind legs of the piglets with your thumb, forefinger and middle finger. If the fetal position is not correct, the fetal position of piglets can be corrected first, and then pulled. If both ends are pulled into the birth canal at the same time, one end can be pushed in first, and then midwifery can be carried out according to the above method.
Instrumental midwifery: Obstetric hooks and traction ropes are generally used, which may even cause death to piglets and damage the sow's birth canal, and are generally operated by those with clinical experience. Obstetric hooks can be made temporarily according to the degree of dystocia of sows, usually with wire. One end of the wire is bent with a small hook with a diameter of about .5cm and a length of about 4cm. During midwifery, the obstetric hook is placed in the palm of your hand and held by your thumb, forefinger and middle finger. The hand rotates slowly in a conical shape and extends into the sow's birth canal. The obstetric hook is hooked to the piglet's orbit or mandibular space with your thumb and forefinger for traction. One end of the obstetric rope is tied with a loop, which is pinched by thumb and forefinger and extended into the birth canal together, and then the maxilla or forelimb (normal) and hind limb (inverted) of the piglet are sleeved and slowly pulled. It is best to pull during midwifery at the same time as the sow's efforts.
sow care after midwifery: after midwifery, intramuscular injection or placing antibacterial and anti-inflammatory drugs in uterus, and washing with .1% potassium permanganate solution from disposable vas deferens once a day for 3-5d.
Treatment of stillbirth dystocia: For a few sows with signs and manifestations of parturition in binary miscellaneous clinic, which are close to the delivery period or longer than the delivery period, the vas deferens is connected with a syringe to inject saline solution with the concentration of 1% ~ 3% and the temperature of 36 ~ 38℃ into the uterine cavity of the sow until the saline solution flows out of the sow's vulva, and then oxytocin is used in combination. After 2 hours, the contents of sow uterus can be discharged. However, it must be noted that oxytocin cannot be injected when the sow's cervix is not open, the pelvis is narrow and the birth canal is obstructed; Within 5 days after delivery, penicillin and streptomycin should be injected intramuscularly every day to prevent inflammation of reproductive tract.
Other methods: If the sow fails to give birth to the fetus for a long time, the delivery worker can hold the sow's rear abdomen with both hands, and with the sow's hard work, push it in the hip direction.
2.2.3 surgical midwifery method-caesarean section
preparation before operation
check the sow's temperature, pulse rate and respiration rate, which are all within the normal range, before caesarean section can be performed.
surgical instruments should be prepared
hemostatic forceps, tweezers, sterile gauze, bandages, suture needles, various types of silk thread, etc., and some medicines and heat preservation equipment should be prepared for later use.
Baoding
Sows lie on their right side in a clean pigsty to fix their heads and limbs.
5ml of 1% glucose saline, 4 million iu of penicillin
and C2ml of vitamin were used for infusion.
Operation
Determination of the surgical site
The left abdominal wall leads a vertical line from the hip tubercle to the abdomen, and then leads a parallel line forward from the knee joint of the hindlimb that has been pulled backward. About 5
cm away from the intersection of these two lines is the beginning above the incision, and the skin is cut slightly forward and downward along this point, and the incision length is 2cm.
The disinfection and anesthesia department cleaned, shaved and rubbed with 5% iodine tincture for disinfection. Use .5% ~ 1% procaine hydrochloride < P > 2 ~ 3 ml for subcutaneous and muscle infiltration anesthesia along the incision line. It is best to inject chlorpromazine hydrochloride (.1mg/kg body weight) subcutaneously or intramuscularly as basic anesthesia before operation.
Operation method
Bluntly separate subcutaneous fat, muscle and muscle membrane with a knife handle, lift the peritoneum with two hemostatic forceps clamps, and cut the peritoneum between the two clamps. Take out the pregnant horn of one side of the uterus, and put a large piece of sterile gauze between the horn of the uterus and the surgical incision to prevent the intestinal tube from escaping and the liquid in the incision uterus from flowing into the abdominal cavity. Make a long longitudinal incision near the uterine body along the uterine curvature
Pay attention to avoid large blood vessels.
First, take out the fetus close to the incision, and then press the other fetuses with their fingers to move forward to the incision and take it out. When taking out each fetus, tear the fetal membrane first, and do not peel off the placenta after taking out the fetus, so as to avoid maternal placental capillary rupture and bleeding. Leave the fetus to the assistant. After confirming that there is no fetus left in the uterus, wash the surface of the uterus with normal saline, fully absorb the liquid on the outer wall of the uterus with sterile gauze, sprinkle cyanine and streptomycin powder in the uterus, continuously sew the serosa muscle layer of the uterus with No.4 silk thread, and then perform node inversion to sew the serosa muscle, apply anti-inflammatory ointment, and send the uterus back to the abdominal cavity. After the uterus is sent back to the abdominal cavity, it can be returned to its original position as much as possible, and at the same time, 5
ml of heated physiological saline is added to the abdominal cavity to fill the lost peritoneal fluid. Then suture the peritoneum continuously with thread 4, and suture the muscles with nodules. Apply blue and streptomycin powder, suture the skin with No.7 silk knot, and finally make 4
needle tension reduction suture, apply 5% tincture of iodine, tightly bind it with bandage and tie abdominal bandage, inject 5 million IU tetanus antitoxin into muscle after operation, and continue infusion.
Postoperative care
After the operation, the sow is moved to the high bed in the delivery room to be kept warm with the heat-preservation lamp, and the piglets are regularly assisted to breastfeed, and then placed in the heat-preservation room after sucking.
After operation, intravenous drip was used for 5
d, with 15ml of 5% glucose saline every day, 8 million IU of penicillin, 4 million IU of streptomycin, 6mg of dexamethasone, 3ml of 1% sodium caffeine and C4ml； of vitamin. At the same time, oxytocin was injected intramuscularly for 3
d every day to promote the discharge of fetal membranes.
after the 4th day, penicillin 4 million IU and streptomycin 2 million IU were injected intramuscularly twice a day for 3
d.
Feed was forbidden within 24 hours after operation, and then a small amount of feed was given, and gradually increased. After 5 days, normal diet was restored, and the wound was taken out 1 days after operation.
3. Prevention of sow dystocia
3.1 Strengthen the management of sow feeding to ensure the reasonable feeding of sows during pregnancy. The feed is full-price and high-quality, and the nutritional level is appropriate, especially to meet the needs of vitamins and minerals closely related to reproductive function, and flexibly control the feed according to the comprehensive factors such as pig size, parity, season and temperature, so as not to make the sow over-nourished or too deficient, resulting in overweight and emaciation of the pig, and to keep the sow moderately fat, which can reduce the occurrence of dystocia. Primiparous sows must be strictly controlled.
3.2 ensure that the environment, especially the production bar, is quiet and the temperature and humidity are appropriate. Let pregnant sows exercise properly, and it is best to feed them in the traditional pig house
1
month before delivery and let them move freely. Exercise can not only improve the physical strength and health of sows, but also exercise the tension of uterine muscles, which is beneficial to the delivery of fetuses and can reduce the occurrence of dystocia. Carefully take care of the late pregnancy and sow production, and the sow should be guarded by a special person during labor, so that dystocia can be found early and treated in time.
3.3 sows that are older, have more births, are weak, fat and have narrow birth canal should be eliminated in time.
3.4 High standards and strict selection of reserve pigs
It is required that the hindquarters are plump, the tail roots are held high, and the vulva is well developed. Adhere to the appropriate age of 8 months or more and the appropriate weight of 11kg or more.
3.5 Pay attention to seed selection and matching, and avoid inbreeding
3.6. Keep the epidemic prevention level well
Adhere to the viewpoint of systematic epidemic prevention, vaccinate all kinds of vaccines with high quality according to immunization procedures, disinfect, repel insects, mosquitoes, timely and effectively diagnose and treat all kinds of common diseases, and control the occurrence of mummies, stillbirths and deformed fetuses.
4. Summary
4.1 For dystocia, early detection and identification of the cause is the key to treatment, and pigs should not be assisted blindly.
4.2 when using oxytocin for dystocia midwifery, we must grasp the timing, dosage and frequency of use, and never abuse it indiscriminately, otherwise it will not only fail to achieve the purpose of midwifery, but also lead to an increase in stillbirth rate, which is a greater harm to sows.
4.3 in the process of artificial midwifery, midwives should try their best to prevent the birth canal from being damaged.
4.4 when artificial midwifery is performed, it must be forced, and it is not allowed to perform broken fetus midwifery.
4.5 After artificial midwifery, the sow's birth canal should be disinfected and sterilized in time, and at the same time, the sow should be injected with antibacterial drugs to prevent infection.
4.6 Strengthen the postpartum care of sows assisted by artificial midwifery, and feed more concentrated feed, so as to make the sows recover quickly.
In short, comprehensive technical measures should be taken to prevent and treat dystocia of sows and create more benefits for pig farmers.