175 The weather at the checkpoint is too bad.

Hot weather lasts for a long time in summer, especially in the south of China. The daily average temperature is higher than 25℃75 ~ 175d, and the highest temperature in summer can reach 33 ~ 39℃. The suitable temperature for fattening pigs is 15 ~ 25℃. When the temperature is too high, the feed intake of pigs decreases, the growth rate is slow, and the feed conversion rate decreases, resulting in the delay of slaughter 15 ~ 20 days. Therefore, how to do a good job of heatstroke prevention and cooling in large-scale pig farms in high temperature season and create a relatively suitable environment for fattening pigs is an important problem for technicians and pig farm managers. The two large pig farms (654.38+10,000 pigs per year) served by the author attach great importance to the feeding and management of pigs in high temperature season and have achieved good breeding results. Relevant prevention and control measures are arranged as follows, and communicated with peers.

1 Effect of high temperature in summer on finishing pigs

1. 1 decline in physiological function

Continuous high temperature in summer will accelerate the respiratory frequency and blood circulation of pigs, and excessive breathing will lead to lung injury in pigs, which is manifested as pulmonary congestion, capillary rupture and respiratory system function decline. In high temperature season, pigs sweat a lot, which on the one hand leads to dehydration and electrolyte disorder, while water consumption increases and food intake decreases. At the same time, it can slow down gastrointestinal peristalsis, reduce the secretion of digestive enzymes, reduce digestive function, and easily induce digestive system diseases. On the other hand, a large amount of water in pigs is excreted through the body surface and respiratory tract, and is greatly reduced through the kidneys.

At the same time, it causes the secretion of antidiuretic hormone to increase, increases the reabsorption of water by renal tubules, leads to urine concentration and even red urine. In addition, high temperature will also cause the central nervous system disorder of pigs, the body is in an extremely weak state, the resistance is reduced, and it is easy to induce diseases such as intestinal bleeding syndrome.

1.2 production performance decreased.

Heat stress changes the normal endocrine activities of the body, leading to the disorder of secretion of hormones such as thyroxine and adrenaline in pigs, which leads to the decrease of metabolic activities of sugar, fat and protein and the decrease of daily gain. High temperature reduces the excitability of the feeding center of pigs, which leads to the decrease of feed intake, appetite and daily gain of pigs. At the same time, in order to adapt to the high temperature environment, the proportion of nutrients used to resist heat stress is relatively increased, while the proportion used for production is relatively reduced, which further reduces the production performance, seriously affecting the economic benefits of pig farms.

1.3 induces many diseases.

High temperature environment is conducive to the reproduction of pathogenic microorganisms and easy to induce many diseases. High temperature environment leads to excessive heat accumulation in animals, dehydration, acid-base imbalance and tissue hypoxia, which is easy to cause heatstroke and heatstroke. In severe cases, it can lead to central nervous system imbalance and cardiopulmonary compensatory failure and death. High temperature creates conditions for parasite reproduction, which easily leads to the occurrence and prevalence of parasitic diseases.

2 heatstroke prevention and cooling measures

2. 1 spray cooling and ceiling fan cooling

Install a spray cooling system in the pigsty. When the temperature of the pigsty reaches above 25℃, the spray cooling system can be started. During operation, the sprinkler should be turned on for 2 ~ 3 min, and then turned off for 0.5 h to make the water evaporate and take away the heat. The spray cooling system combined with ceiling fan has better effect. In addition, conditional pig farms can install automatic sprinklers on the roof to cool the roof. Generally, pig farms can also wash the walls and floors of pig houses with tap water pipes to reduce the temperature.

2.2 Shading and greening environment

Building a black sunshade net outdoors or on the roof, or planting climbing vines such as grapes and loofah, covering the wall to avoid direct sunlight, can greatly reduce solar radiation; You can also paint white lime on the sunny side of the roof and outdoor walls of the pigsty to enhance sunlight reflection; in addition

In addition, planting trees around the pig house can also absorb some heat and reduce the environmental temperature of the pig farm.

2.3 Ventilation and cooling

Install high-power exhaust fan and fly screen window in the pigsty, open all doors and windows of the pigsty for ventilation, and keep the pigsty in good ventilation condition and sufficient ventilation; Skylights can also be opened on the roof, with the general size of 1.2m× 1.0m, and 1 every 20m2. By accelerating air exchange

Reduce the temperature of pigsty and the concentration of harmful gases such as ammonia and hydrogen sulfide in the air.

2.4 Wet curtain fan cooling

In recent years, the cooling system in wet curtain fan has developed rapidly, and the cooling effect is remarkable. When the thickness of the wet curtain is 12cm and the wind speed passing through the wet curtain is 1.0 ~ 1.2 m/s, the temperature of the pigsty can be reduced by 5 ~ 7℃. The drier the air, the higher the temperature, and the greater the temperature drop of the air passing through the wet curtain.

3 feeding management measures

3. 1 Adjust the feeding time

Stop feeding when the temperature is high at noon in summer and start feeding when the temperature is low in the morning and evening, which can increase the feed intake of pigs and ensure their normal growth and weight gain. According to the actual situation of the pig farm, the feeding time can be arranged from 6: 00 am to 7: 00 am and 7: 00 pm.

3.2 Supply green feed

Green and juicy feed is rich in water and vitamins, has good palatability and can improve the appetite of fattening pigs. In addition to providing full-price compound feed, we should also feed green and juicy feed at 65438+ 02: 00 noon and 3: 00 pm according to the amount of 2 kg per pig per day, and supplement salt appropriately.

3.3 Supply sufficient and clean drinking water

For the temperature regulation of pigs in summer, clean drinking water is the most critical. Provide them with clean and cool drinking water in summer and let them drink freely. A variety of vitamins and electrolytes can be added to drinking water to enhance the body's ability to resist thermal stress and maintain the stability of the body's internal environment, which is beneficial to pigs.

It is of great significance to restore appetite and maintain normal weight growth.

4 epidemic prevention measures

4. 1 disinfection

Regularly clean the pigsty to ensure good ventilation, and regularly disinfect the internal and external environment of the pigsty (including pigsty, site, utensils, drainage channels, pig body surface, etc.). ). Check whether the screen window is in good condition, light mosquito-repellent incense at night or enable electronic mosquito killer to kill mosquitoes and flies.

4.2 Disease prevention

Pigs are prone to swine fever, eperythrozoonosis, streptococcosis and other diseases in high temperature season, so it is necessary to strengthen the prevention of common diseases. Immunization of common infectious diseases should be carried out according to the epidemic situation in this field. In addition, parasites inside and outside pigs should be removed regularly.

5 Heat stroke treatment (1) Move the sick pig to a cool place, and cool it with air conditioner, ceiling fan or cold water. Note that cold water can't directly flush the head, and the body surface of sick pigs should be cooled first in the chest and back, first in a small area and then in a large area. Severe cases can be treated with cold water enema. (2) medication. Physical cooling combined with drug therapy: chlorpromazine 2 ~ 3 ml/kg body weight, analgin 2 ~ 6 ml, intramuscular injection after mixing, 3 times/d; Sodium camphor sulfonate 5 ~ 10 ml, 1 time /d can also be injected intramuscularly. For pig farms that are difficult to obtain drugs in a short time, 250 ~ 500 ml of saline can be injected intravenously for saline enema.