When raising pigs in winter, keep in mind that pigs have “five fears.” Farmers should take preventive measures in advance in five areas to help pigs get through the winter safely.
Fear of cold
The suitable growth temperatures for pigs are 32~35°C for newborn piglets, 20~22°C for nursery pigs, and 15~20°C for medium-sized and large pigs. Low temperatures have a serious effect on pig growth and weight gain. When the temperature in the pig house falls below the lower limit of the suitable temperature range, every decrease of 1°C reduces daily weight gain by about 17 grams. If the temperature in the house falls below 4°C, the rate of weight gain decreases by 50%, and feed consumption increases by more than 1 times.
Sensitive to dampness
The suitable humidity levels for different pigs are: piglets, 50%~70%; fattening pigs weighing 40~80 kilograms, 70%; fattening pigs weighing 80~110 kilograms, 80%; and breeding sows, 55%~80%. In winter, piglets in pig houses with high relative humidity have an average weight gain about 48% lower than that of the control group. Piglets are also prone to diarrhea, enteritis, and diseases such as piglet paratyphoid. This can be addressed through ventilation, increased exposure to sunlight, and laying dry bedding.
Sensitive to cold
When the water and feed temperatures are 0℃, raising them to body temperature, 39℃, requires the pig to consume 682~878 kilocalories of heat energy. This is equivalent to 0.5~0.75 kilograms of concentrate feed being wasted each day on maintaining body temperature. Therefore, in winter, when raising piglets and sows, it is best to provide warm feed and warm water, at a temperature of about 37℃.
Fear of drafts
In winter, pigs are most afraid of “through-drafts” and “sneaky drafts.” These not only lower the temperature in the pigsty but also make pigs more susceptible to colds, strokes, rheumatism, and other diseases. In winter, seal gaps in the pigsty, hang straw curtains, and keep doors and windows tightly closed to prevent “sneaky drafts” from blowing in and affecting pig growth and development.
Fear of disease
If the pigsty is cold, humid, unhygienic, and poorly ventilated and lit in winter, pigs are more likely to become ill. Therefore, strengthen feeding and management, keep the pigsty ventilated, clean, and dry, and disinfect it regularly. Also observe the pigs’ appearance, mental state, feed intake, feces and urine, and breathing. If a pig becomes ill, diagnose it promptly and isolate and treat it as early as possible.
Pig Barn Disinfection and Ventilation Management
Thoroughly disinfecting and ventilating pig farms is one of the key measures for eliminating sources of infectious diseases and preventing disease outbreaks. This is especially important during the cold winter months, when temperatures are low and pig barns are gradually sealed, restricting ventilation and making it easy for harmful substances such as bacteria and viruses to accumulate in the air. Therefore, to ensure healthy pig growth, winter disinfection and ventilation management in pig barns must be maintained at all times.
Pig Barn Ventilation
Ventilation can be provided as appropriate between 10 and 14 each day. Pay attention to the ventilation openings in the pig barn to prevent cold winter drafts from blowing directly onto the pigs and causing illness due to cold stress. Cleaning out manure releases large amounts of harmful gases, so open the windows for ventilation before starting to remove the manure. Also, keep the pens clean. On sunny days, rinse the floor with water in the afternoon, then ventilate the barn and let it dry. This helps ensure that the pigs breathe fresh air at night and is very beneficial for preventing respiratory diseases. Take the “150 Standardized Pig-Raising Model” as an example: it uses negative-pressure ventilation, an exhaust-type system that removes large amounts of foul-smelling air from the barn, helping maintain good indoor air quality. The fan speed should ideally be fixed at 1.5 meters/second. If it is too low, foul odors will not be effectively expelled; if it is too high, additional heat must be provided in the heating flue.
Pigsty disinfection
Before disinfection, first carry out thorough sweeping. After removing feed from the troughs, manure, and debris from the drains, wash the area carefully. Once cleaning is complete, fumigate with formalin, then disinfect thoroughly with 2% caustic soda, peracetic acid, Weidao, complex iodine, and other products. Note that equipment inside the pigsty, such as insulation boards and feed troughs, must also be disinfected thoroughly. After disinfection, leave the pens empty for 5~7 days before introducing pigs. If disinfecting while pigs are present, first consider the choice of disinfectant: strongly acidic, strongly alkaline, and highly corrosive disinfectants are unsuitable. Also, disinfect on a clear day when the temperature is relatively high. At such times, the disinfectant, after being atomized and diluted, can not only kill pathogens but also provide some cooling. Disinfectants such as strong-acting iodine and chlorine dioxide are recommended. When using them, take care not to use a concentration that is too high.
How to improve pigs' immunity
In winter, pigs increase their basal metabolic rate to maintain body temperature, and about one-third of the feed they eat is used to sustain metabolism. Therefore, when raising pigs in winter, ensure they eat enough to achieve the best results. It is recommended to add an extra feeding in the evening to increase daily weight gain and reduce the feed-to-meat ratio. Feeding pigs a high-energy diet is also recommended. For farmers using concentrate feed, it is recommended to reduce the amount of wheat bran in the formula and increase the proportion of corn. Users of piglet pellet feed are advised to use high-energy pellets for better economic returns.
Changes in winter temperatures can easily trigger some infectious diseases, such as transmissible gastroenteritis, epidemic diarrhea, and foot-and-mouth disease. Check the pigs’ immune status, particularly for infectious diseases common in cold weather, to ensure they have sufficient immunity. In addition, strengthen biosecurity at the pig farm, prohibit unauthorized entry and exit, and reinforce disinfection measures to prevent infectious diseases.
Vaccinate pigs in a targeted manner, ensuring that all animals requiring vaccination are vaccinated and none are missed. Use Chinese herbal medicine as the main approach, with antibiotics as a supplement, and carry out regular medication-based prevention and health care according to the dosage and course of treatment to prevent antibiotic misuse. Promptly isolate and treat any suspected sick pigs, ensuring early detection, early diagnosis, early treatment, and early handling. All pigs that die of disease must be subject to the “four prohibitions and one treatment” (not sold, slaughtered, transported, or discarded; instead, disposed of harmlessly). Keep sick pigs in a separate group from healthy pigs to prevent contact transmission.