How to Tell if a Sow Has Stillborn Piglets? A Detailed Guide to Identification Methods

In pig farming, besides directly purchasing piglets, you can also breed through sows. And during a sow's pregnancy, the impact of stillbirths and other issues is quite significant.So how do you tell if a sow has stillborn piglets? What causes this situation?

How to tell if a sow has stillborn piglets?

Use your hands to palpate the sow's abdomen and check for fetal movement; if there is none, it may be a stillbirth. In addition, if during her gestation there is discharge of lochia from the vulva, lethargy, refusal to eat, and often systemic symptoms such as elevated body temperature, rapid breathing, and accelerated heartbeat, then it can be determined to be a stillbirth.

What causes stillborn piglets in sows?

1. In late gestation, forcibly driving the sow, fright, crowding and other mechanical stress can easily cause stillbirths.

2. Effects of heat stress: when the temperature exceeds 30°C, the sow's endocrine and metabolic functions become abnormal, and too much energy consumption leads to weak farrowing and stillbirths. In addition, heat stress can easily cause early embryonic death in sows.

3. During the process of adapting to stress, fever and functional decline often occur, and the use of hormone drugs or antibiotics can easily cause stillbirths.

4. Under high temperature, reduced oxytocin secretion in the sow prolongs the farrowing process; at the same time, reduced feed intake leads to insufficient fetal nutrition and causes stillbirths.

5. High temperature accelerates the destruction of vitamins in feed, while pigs need more vitamins to fight heat stress, worsening the impact of vitamin deficiency.

6. High temperature makes pigs breathe faster and enhances peripheral blood circulation, while blood circulation in the internal reproductive system weakens, causing insufficient blood supply to the embryos, while the fetus's metabolism increases under high temperature and its nutritional needs are greater, undoubtedly worsening fetal malnutrition. Overall, increased demand with reduced supply is the main cause of stillbirths.

7. Pregnant sows kept in crates with high stocking density have difficulty dissipating heat, especially sows in late gestation and near farrowing, and sows in late gestation eat more, so their body temperature rises to 39.5°C after eating. When the body temperature of sows in late gestation remains at this level for a long time, the stillbirth rate increases.

8. Damp heat (high temperature and high humidity) is also a main cause of stillbirths. Normally, pigs dissipate heat mainly through conduction and convection, but under high temperature both of these methods are limited. The most effective way is evaporative cooling, but in high-humidity weather, reduced water evaporation lowers the cooling effect, that is, pigs dissipate heat better in dry heat, while heat dissipation is difficult in damp heat, and damp heat increases pigs' sensitivity to heat stress. For example, dry heat at 40°C will not kill sows from heat, but damp heat at 35°C can cause sows to die from heat.

To prevent stillbirths in sows, management of pregnant sows should be strengthened, appropriate nutrition should be provided, and crowding, abdominal impact, falls and blows should be avoided.