Effects of different temperatures on Pigs and its Countermeasures

1. The effect of ambient temperature on pigs

1. The effect on the health of pigs. In the environment of continuous high temperature, the resistance of pigs decreased significantly, the body heat balance was destroyed, the body temperature increased, coma, heat radiation disease occurred, and died in severe cases. In a low temperature environment, pigs contract peripheral blood vessels in order to keep warm, causing local frostbite. Low temperature can cause respiratory diseases, but also often cause rheumatism, arthritis and other diseases. Low temperature has a greater impact on piglets, according to statistics, half of the dead piglets were frozen to death or died of cold-related diseases. Newborn piglets contract peripheral blood vessels to keep warm, causing local frostbite. The incidence of diarrhea and other diseases in newborn piglets increased significantly in low temperature environment.

2. Effect on feed intake of pigs. In a high temperature environment, pigs reduce feed intake in order to reduce heat production in the body. When the ambient temperature is low, the heat dissipation of pigs increases, and the feed intake of pigs increases in order to maintain body heat balance.

3. Effect on feed digestibility of pigs. Ambient temperature affects the residence time of feed in digestive tract. In high temperature environment, the retention time of feed in digestive tract is long, so the digestibility of feed is higher; in low temperature environment, gastrointestinal peristalsis is accelerated, food residence time in digestive tract is short, and digestibility is low.

4. effects on growth, weight gain and feed conversion rate of pigs. In the high and low temperature environment, the maintenance of pigs needs to increase, mainly due to the maintenance of body heat balance (heat dissipation and cold protection), the decrease of feed conversion rate, growth rate and weight gain. Severe cold and heat stress stops the growth and weight gain of pigs, all the feed is used to maintain needs, and weight gain may occur.

5. The effect on pig reproduction. When the ambient temperature was higher than 33 ℃ ~ 35 ℃ and the boar body temperature was more than 40 ℃, the testicular temperature increased, the semen quality decreased, the sperm count decreased, the sperm motility decreased, and the proportion of abnormal spermatozoa increased. Heat stress decreased the libido of boars.

In the hot season, sows often have anestrus and behavioral anestrus (ovulation without symptoms of estrus), and the estrous cycle is also prolonged. Sows were particularly sensitive to high temperature before and 1-3 weeks after mating, when the ambient temperature was too high, the conception rate decreased significantly, and early embryo absorption and death occurred. High temperature affects the normal development of fetus, in addition, it reduces the feed intake of sows, increases the maintenance energy, makes the fetus malnourished and hinders the development of piglets, resulting in low birth weight of piglets, slow growth after birth, and the decrease of immunoglobulin content in sow milk caused by high temperature. the resistance of piglets decreased and the survival rate was low.

II. Measures to be taken under high temperature

1. Improve the level of diet (especially energy, protein and vitamins) and provide fresh, adequate and clean drinking water.

2. Strengthen ventilation and reduce feeding density. Clean up the faeces in time and keep the pig house clean. Shading measures are adopted to reduce sunlight exposure. Spray, shower and bathe to promote evaporation and heat dissipation of pigs.

3. Feed or wet the mixture when it is cool in the morning and evening.

4. Put stress drugs in feed or drinking water, such as vitamin C, quick tonic 14, etc.

Measures taken at low temperatures

1. Ensure the nutritional level of feeding, especially the high energy level, and add oil if necessary. If possible, you can give the pig warm water.

2. Increase the feeding density reasonably and use bedding grass or wood board. Reduce the humidity in the house and remove feces and urine in time.

3. Increase the times and amount of feeding.

4. Do a good job of heat preservation in pig house. To prevent the attack of thief wind, proper ventilation (preferably when the temperature is high at noon), to remove harmful gases and water vapor in the house. Heating measures should be taken when necessary, and open-air feeding should be covered with plastic sheds to facilitate heat preservation.