Does the high temperature weather in summer have any impact on the growth performance of fat pigs? Are there any good countermeasures?
Summer hot weather lasts for a long time, especially in southern my country, where the average daily temperature is higher than 25°C for 75 to 175 days, and the highest temperature in midsummer can reach 33 to 39°C. The suitable temperature for fattening pigs is 15 to 25°C. If the temperature is too high, the pigs' feed intake will decrease, their growth rate will slow down, and their feed conversion rate will decrease, which can lead to a delay of 15 to 20 days in slaughter. Therefore, how to prevent heatstroke and cool down the large-scale pig farms during the high temperature season and create a relatively suitable environment for fattening pigs is an important issue before technicians and pig farm managers. The two large-scale pig farms that the author serves (with an annual output of 100,000 pigs) attach great importance to the feeding and management of pigs in high-temperature seasons and have achieved good breeding results. The relevant prevention and control measures are now organized as follows for communication with peers.
1 Effects of high temperature in summer on fattening pigs
1.1 Decline in physiological functions
Sustained high temperature in summer will accelerate the respiratory rate and blood circulation of pigs, Excessive breathing can cause lung damage in pigs, manifested as pulmonary congestion, rupture of microcapillaries, and reduced respiratory system function. During the high temperature season, pigs sweat a lot, which on the one hand leads to dehydration and electrolyte imbalance in the body. At the same time, water intake increases and feed intake decreases. It can also lead to slowed gastrointestinal peristalsis, reduced secretion of digestive enzymes, and reduced digestive function, which is extremely harmful. It is easy to induce digestive system diseases; on the other hand, a large amount of water in the pig body is excreted through the body surface and respiratory tract, and the excretion through the kidneys is greatly reduced.
At the same time, it causes an increase in the secretion of antidiuretic hormone, making the renal tubules heavy on water. Absorption increases, resulting in concentrated urine and even red urine. In addition, high temperature can also cause disorders in the central nervous system of pigs, putting the body in an extremely weak state and reducing resistance, which can easily induce intestinal hemorrhage syndrome and other diseases.
1.2 Decline in production performance
Heat stress changes the normal endocrine activity of the body, leading to disordered secretion of hormones such as thyroid hormone and epinephrine that regulate substance metabolism in pigs, thus causing The metabolic activities of carbohydrates, lipids and proteins are reduced, and daily weight gain is reduced. High temperature causes a decrease in the excitability of the pig's feeding center, resulting in a decrease in feed intake, loss of appetite, and decrease in daily weight gain. At the same time, in order to adapt to the high temperature environment, the proportion of nutrients used by the body to resist heat stress increases relatively, and the proportion of nutrients used for production increases. The proportion is relatively reduced, and the production performance is further reduced, seriously affecting the economic benefits of the pig farm.
1.3 Inducing various diseases
High temperature environment is conducive to the reproduction of pathogenic microorganisms and can easily induce various diseases. High-temperature environments lead to excessive accumulation of heat in animals, dehydration, acid-base imbalance in the body, and tissue hypoxia, which can easily cause heat stroke and heat stroke. In severe cases, it can lead to central nervous system disorders and death from compensatory heart and lung failure. High temperatures create conditions for parasites to multiply, easily leading 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 pig house. When the temperature of the pig house reaches above 25°C, the spray cooling system can be started. During operation, the sprinkler should be turned on for 2 to 3 minutes, and then turned off for 0.5 hours to allow the water to evaporate and take away the heat. The spray cooling system is more effective when combined with ceiling fans. In addition, qualified pig farms can install automatic sprinklers on the roof to cool the roof. Generally, pig farms can also use tap water pipes to flush the walls and floors of pig houses to lower the temperature.
2.2 Shade and sun protection, green environment
Build a black sunshade net outdoors or on the roof, or plant climbing vines such as grapes, loofah, etc. to cover the walls Avoid direct sunlight, which can greatly reduce solar radiation; you can also paint white lime on the sunny side of the pig house roof and outdoor walls to enhance sunlight reflection; in addition, plant trees around the pig house It can also absorb part of the heat and reduce the ambient temperature of the pig farm.
2.3 Ventilation and cooling
Install high-power exhaust fans and fly screens in the pig house, open all doors and windows for ventilation, and maintain good ventilation conditions and adequate ventilation in the pig house. The amount; skylights can also be opened on the roof. The general size is 1.2m×1.0m, and one is set every 20m2. By speeding up air exchange
reduce the temperature inside the pig house and at the same time reduce the concentration of harmful gases such as ammonia and hydrogen sulfide in the air.
2.4 Cooling curtain fan cooling
The wet curtain fan cooling system has developed rapidly in recent years and has a remarkable cooling effect. When the thickness of the wet curtain is 12cm and the wind speed across the curtain is 1.0~1.2m/s, the temperature of the pig house can be reduced by 5~7℃. The drier the air and the higher the temperature, the greater the cooling rate of the air passing through the wet curtain.
3 Feeding and management measures
3.1 Adjust feeding time
Stop feeding feed when the temperature is higher at noon in summer, and change to morning and evening when the temperature is lower When carried out regularly, it 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 between 6:00 and 7:00 in the morning and 7:00 in the evening.
3.2 Supply green and green feed
Green and juicy feed is rich in water and multivitamins, has good palatability and can increase the appetite of fattening pigs.
In addition to providing full-price compound feed, 2 kg of green and juicy feed should be fed per pig per day at 12:00 noon and 3:00 p.m., and appropriate salt supplementation should be provided.
3.3 Supply sufficient clean drinking water
Clean drinking water is the most critical for regulating the body temperature of pigs in summer. In summer, clean and cool drinking water should be provided for pigs to drink freely. Multivitamins and electrolytes can be added to the drinking water to enhance the body's ability to resist heat stress and maintain a stable internal environment, which is important for pig recovery
It is of great significance to regain appetite and maintain normal weight gain.
4 Epidemic prevention measures
4.1 Disinfection
Clean the pig house frequently to ensure good ventilation, and regularly inspect the environment inside and outside the pig house (including pens) (houses, venues, utensils, drainage channels and pig body surfaces, etc.) for disinfection. Check whether the screen window is in good condition. You can light mosquito coils or activate an electronic mosquito killer lamp at night to kill mosquitoes and flies.
4.2 Disease Prevention
In the high temperature season, pigs are susceptible to diseases such as swine fever, epierythrozoonosis, and streptococcosis, so prevention of common diseases must be strengthened. Immunization against common infectious diseases should be done according to the current epidemic situation. In addition, internal and external parasites in pigs must be removed regularly.
5 Heat stroke treatment (1) Move the sick pig to a cooler place with lower temperature and use air conditioning, ceiling fan or cold water to cool down. Note that cold water cannot be directed to the head. Cool the body surface of the sick pig first on the chest and then on the back, first on a small area and then on a large area. In severe cases, cold water enema can be used. (2) Drug treatment. Physical cooling should be combined with drug treatment: chlorpromazine 2 to 3 mL/kg body weight, metamizole 2 to 6 mL, mixed and intramuscular injection, 3 times/d; sodium camphorsulfonate 5 to 10 mL intramuscular injection can also be used, 1 time/d. For pig farms where it is difficult to obtain drugs in a short period of time, 250 to 500 mL of physiological saline can be injected intravenously and enema can be performed with physiological saline.