Pigs are endothermic animals, and the constant body temperature is achieved by the balance of heat production and heat dissipation. When the ambient temperature exceeds the optimum temperature for pigs and the pigs' heat production is greater than their heat dissipation, the pigs must increase the number of respirations to dissipate heat, or reduce the production of body heat by reducing feed intake to adjust body temperature balance. When the body's body temperature balance cannot be maintained by increasing heat dissipation and reducing heat production, it will cause the pig's body temperature to rise. If pig body heat is accumulated and cannot be dissipated, and the body temperature remains high for a long time, it will cause changes in the pig's nervous system and endocrine system, causing heat stress in the pig.
The specific manifestations of pigs under heat stress are: depression, elevated body temperature, rapid heartbeat, rapid breathing, and even panting; reduced feed intake, increased water drinking, lethargy, and reduced activity , elongate the body when lying down, and like to sleep in wet places, which can lead to reduced production performance, prolonged labor of sows, increased stillbirths, and poor semen quality of boars.
Measures to deal with high temperature heat stress in summer:
1. Heatstroke prevention and cooling in pig houses. At the beginning of construction, the new pig house uses thermal insulation materials, combined with wet curtains and negative pressure fans to ensure a comfortable temperature in the pig house. Depending on the situation, old pig houses can use awnings, fans, ventilation, air coolers and other measures to cool down and alleviate heat stress.
2. Appropriately reduce the stocking density. In order to facilitate the heat dissipation of the pig body, the feeding density of fattening pigs can be appropriately reduced, and the area occupied by each pig is preferably 1.2-1.5 square meters.
3. Pay attention to feed nutrition. In summer, feed more easily digestible feeds such as green and juicy foods rich in vitamins and minerals, as well as pouring wheat bran, to reduce the calories consumed by pigs' physical metabolism. In addition, it is recommended to add 300g vitamin C, 200g vitamin E and 250g baking soda per ton of feed, or add 0.25 Oldman A directly to the feed to enhance the adaptability and heat resistance of pigs and reduce stress.
4. Adjust the feeding time. Avoid feeding pigs during the hottest period. Feeding can be done between 5 a.m. and 7 a.m. and after 16 p.m. Because the temperature is relatively low, the pigs’ feed intake can be ensured.
5. Keep feed fresh and plenty of clean drinking water. In the high temperature and high humidity in summer, it is necessary to keep pig feed as fresh as possible to prevent mildew and oxidation. The corners and gaps of the barrels and troughs must be cleaned regularly. The amount of water consumed by pigs increases significantly in summer. It is necessary to frequently check whether the drinking water pipes are blocked to ensure clean and sufficient drinking water supply.