How to raise pigs in hot weather

In recent years, the continuous high temperature weather in most parts of China in summer has greatly affected the reproductive performance of pigs in large-scale pig farms. In view of this phenomenon and problem, the author analyzed and discussed how to overcome and alleviate the adverse effects of high temperature on pig reproduction for reference. 1. Adjust diet formula to ensure proper nutrition level. Modern nutrition research shows that appropriate nutrition level is the decisive factor to improve the health level and reproductive performance of breeding pigs. High temperature reduced the feed intake, energy and protein intake of breeding pigs. Therefore, whenever summer enters the high temperature period, it is necessary to adjust the diet formula, improve the energy and protein level in the diet, and ensure the nutritional level conducive to the normal reproduction of breeding pigs. The specific methods are as follows: ① On the basis of the original diet, boars feed 2 eggs per head every day. Conditional pig farms should feed an appropriate amount of green feed or 2%-5% fat (due to less calories produced by fat digestion), instead of carbohydrates with the same energy value. ② It is necessary to maintain a high nutritional level (crude protein ≥ 16%, digestible energy ≥ 13.39mj//kg), feed 2.5-3.2 kg per day four weeks before delivery, and feed more than 4.5 kg during lactation. ③ Weaned sows or reserve sows 2-3 weeks before mating should be fed with high nutritional level diet-short-term advantage feeding with milk to promote estrus and ovulation, restore sow weight, store nutrition for mating, fertilization and embryo development, and the daily feeding amount should be guaranteed to be above 2.2-2.5 kg. ④ After mating, sows are fed low-energy and low-protein diet (crude protein is not higher than 14.5% and digestible energy is not higher than 12.97mj//kg), and the daily feed intake should be reduced to 1.5-2kg. From the 4th week after mating to the 4th week before delivery, sows should maintain a moderately low nutritional level (crude protein 14.5%, digestible energy not higher than 13.8mj/ kg), and the daily feed intake can be controlled at 1.8-2.2 kg. Overfeeding not only wastes feed, but also increases the metabolic burden of sows (especially in high temperature period), which is more likely to lead to anorexia or reduced feed intake during lactation, resulting in excessive weight loss of sows and decreased lactation ability, which is unfavorable to sow fertility and piglet development. 2. Provide enough cool drinking water to control the temperature rise of pigs. Water plays an important role in regulating the body temperature of pigs. In high temperature environment, pigs mainly rely on water evaporation to lose body heat. Insufficient drinking water or high water temperature will reduce the heat tolerance of pigs. Experiments show that the water consumption of pigs increases with the increase of environmental temperature. When the temperature is 7℃-22℃, the ratio of water consumption to dry matter intake is 2.1-2.7:1; When the temperature rises to 30℃-33℃, the ratio of water consumption to dry matter intake increases to (2.8-5): 1. It can be seen that drinking water is absolutely necessary for the health and reproduction of pigs under high temperature conditions. 3. Change the feeding, exercise and breeding time. Whenever entering the hot season, pig farms should change the feeding time of pigs, and breakfast should be early, which can be around 6 o'clock; Dinner will be late, it should be around 19; Lunch can avoid feeding at noon, which can make full use of pigs to eat more feed when the weather is cool. The wet mixture can be wetter and fed with green feed to improve palatability and promote food intake. For boars, reasonable exercise is a necessary means to improve their health and reproductive ability. In the hot season, we should stick to it, but it should change with the change of feeding time, that is, we should drive for 0.5- 1 hour every day after feeding early and before feeding late. These two breeding or sperm collection can also be arranged about 0.5 hours after exercise in the morning and afternoon, so that boars can rest as much as possible at noon. On the other hand, the most direct effect of high temperature on breeding pigs is the decrease of sexual desire and the delay of estrus. Therefore, in the high temperature period in summer, we can make full use of the boar effect to make up for the adverse effects of the decline in sexual desire caused by high temperature.