What are the symptoms of heat stress in pigs? How can pig farmers identify them

Heat stress in pigs refers to the sum of non-specific physiological responses made by the animal body to a hot environment when in a high-temperature environment. During pig farming, careful observation is necessary, and if symptoms of heat stress in pigs appear, timely treatment should be given. So what are the symptoms of heat stress in pigs?

I. What are the symptoms of heat stress in pigs

In mild cases, abdominal panting, difficulty breathing, elevated body temperature, and flushed skin appear; in severe cases, death from heatstroke occurs, especially in summer, when the temperature is too high, the pigs are too fat, and certain individual breeds show stress, with feed intake declining, thereby affecting the pigs' production performance, growth and development and speed, and seriously affecting the economic benefits of the pig farm. Its effects are shown as:

1. Stress in breeding pigs: In sows, it is shown as reduced ovarian function, decreased conception rate, and an increased return-to-estrus rate caused by failure of fertilized egg implantation; in late gestation, due to insufficient supply for maintaining their own oxygen consumption, fetal death occurs, piglets are born with low vitality, the number of stillbirths increases, litter weight decreases, and even miscarriage and stillbirth occur; in boars, libido weakens and semen quality declines. For boars, high temperature makes the proportion of pigs with no libido higher than in normal-temperature seasons, and the ejaculate volume of boars decreases, more easily causing the occurrence of heat-stress sudden death; lactating sows' appetite declines, causing feed intake to drop, leading to a decline in milk yield and quality of lactating sows, and finally secreting fat milk converted from body fat, causing piglet diarrhea and slow growth, affecting piglet survival rate and weaning weight.

2. Growing pig herd: The reduction in feed intake caused by heat stress, by reducing body heat production to regulate body temperature balance, causes organic diseases, resulting in increased feed consumption, slower growth speed, reduced feed conversion rate, and greater production costs, thereby affecting the pigs' weight gain and resistance to the external environment.

II. What to do about heat stress in pigs?

1. Reduce heat radiation on the pig herd. The pig farm should be built close to a water source or woods, sunshade netting should be covered above the pig house, vines should be planted in front of the pig house, and lime should be applied to the outer walls of the pig house to enhance direct sunlight.

2. Ensure good ventilation in the pig house, make sure the windows of the pig house are fully open, and that air circulates quickly, which helps the pigs dissipate heat. High-power electric fans can be installed in the pig house to speed up air circulation.

3. Take good cooling measures in the pig house, frequently flushing and sprinkling the ground with water, but promptly sweeping away accumulated water and sewage; if conditions permit, spray devices can be installed in the pig house to increase air humidity, which helps cooling through the principle of evaporative vaporization and heat absorption.

4. Provide sufficient clean drinking water. Due to high temperatures, the water intake of pigs will increase, and sufficient drinking water helps pigs dissipate heat; in addition, Chinese herbal medicine can be added to the water to prevent heat stress in pigs.

When summer comes, promptly taking cooling measures on the pig farm can effectively reduce the incidence of heat stress in pigs. If there is no heat stress on the pig farm, production capacity will naturally go up.