How to prevent and treat false pregnancy in sows? They appear pregnant but produce no piglets

    After a sow comes into estrus and is mated, she shows no obvious signs of returning to estrus and appears pregnant. As time passes, the sow shows symptoms similar to normal pregnancy. When the gestation period is over and farrowing approaches, although signs of labor appear, no piglets are produced. This condition is called false pregnancy in sows. After a false pregnancy, the sow consumes feed for a long time while the breeding plan fails, causing losses. The prevention and treatment methods for false pregnancy in sows are introduced below for readers' reference.

Sow

    1. Clinical symptoms: False-pregnant sows show almost normal estrus behavior. After mating, as time passes, the sow has reactions similar to normal pregnancy: slow movement, gradual recovery of body condition, and slight but not obvious abdominal enlargement. Before farrowing, the affected pig shows nest-building behavior by carrying straw in her mouth, is restless, defecates and urinates more frequently, and has swelling of the vulva, but no mucus discharge. Although the udder is obviously swollen and milk can be squeezed out, the milk is scant and thin. At farrowing, the sow shows obvious signs of labor and straining. After several rounds of straining, no amniotic fluid is seen, the abdominal circumference suddenly shrinks, and no piglets are produced.

    2. Clinical diagnosis: False pregnancy can occur in sows of different breeds, ages and parities in all four seasons. Even when a false-pregnant sow is standing, there is no obvious change in the abdomen and no obvious hollowing of the back; when lying quietly, no fetal movement can be seen; when the abdomen is felt by hand, no fetus can be felt and no fetal movement can be perceived.

    3. Cause analysis: (1) After the sow comes into estrus, although natural mating or artificial insemination is carried out, she does not conceive. However, the corpus luteum formed on the ovary not only fails to regress but continues to secrete progesterone, resulting in pregnancy-like signs. (2) The sow nurses and raises piglets for a long time, is thin in body condition, loses condition severely, and consumes a large amount of the body's nutrient reserves; she may even develop lactation paralysis, leading to disorder of the sow's hormonal secretion regulatory function. (3) Feed nutrition is unbalanced. Long-term feeding of a single feed leads to deficiency of vitamins and trace elements, especially vitamin E deficiency. (4) Reproductive tract diseases cause ovarian dysfunction. (5) Misuse or abuse of hormone drugs to induce estrus. (6) Internal parasites invade the reproductive system.

    4. Comprehensive prevention and treatment: (1) Do a good job of feeding by stages to prevent the sow from being too fat or too thin. Provide green fodder as much as possible, pay attention to vitamin E supplementation, add sodium selenite vitamin E powder, or supplement the sow's feed with soaked and sprouted barley. (2) If the sow's estrus is abnormal, do not rush to mate; targeted treatment measures should be taken. Under natural conditions, mate again after normal estrus occurs. (3) Do a good job of "short-term flushing" for weaned sows. Sows just weaned and separated should have intensive feeding management and an appropriate supplement of protein feed. After each weaning and separation, deworming and epidemic prevention should be carried out once. For sows in especially poor body condition, mate only after body condition has effectively recovered. (4) Carefully observe the sow's behavior after mating, and if a false-pregnant sow is found, take measures as early as possible to terminate the false pregnancy. (5) To prevent reproductive tract diseases from affecting ovarian function, inject penicillin intramuscularly after the sow farrows, twice a day for 3 consecutive days. (6) Select hormone drugs in a targeted way to induce estrus, and it is best to mate under natural estrus. (7) Combine with drug treatment: intramuscular injection of 1-2 mg prostaglandin, or 1-2 mg methyltestosterone.