Spring is a season of rejuvenation for all things, but for the pig farming industry, it’s also a season prone to the prevalence of diseases. The majority of pig farmers must pay attention to relevant precautions for spring pig farming, effectively prevent and control diseases, and reduce economic losses.
1. Why Diseases Are Prone to Occur in Spring
Spring is a transitional season as the climate shifts from cold to warm. All living things begin to recover, and this recovery isn’t just what we can see with our eyes. Various microorganisms and fungi, including pathogenic viruses, bacteria, and molds that affect pigs, also revive. Their resurgence poses a threat to the pig farming industry. Furthermore, the climate change doesn’t happen all at once in a short period. Every year, there is a period of “spring cold snaps” (false spring), during which temperatures fluctuate greatly. The body needs to adapt to this, and it’s also a period of adjustment for the immune system. If temporary immune decline occurs, it can easily lead to diseases. Pigs are also animals, and their physiological characteristics change with the climate. Many pig farms consider spring a key season for disease prevention.
2. Pig Farming Precautions
2.1 Pay Attention to Disease Monitoring
Spring is a high-risk period for disease outbreaks. During this sensitive season, pig farms should strengthen daily inspections to monitor disease occurrence. During inspections, relevant personnel must carefully observe each pig, including their gait, whether there are abnormalities in feed and water intake, whether they lie alone in a corner, whether their breathing is normal, whether they frequently have tear stains, whether their growth rate is significantly lagging, whether their feces are unformed, whether they are sensitive to external stimuli, and whether their mental state is good. This is because disease development always follows a process of occurrence, development, climax, and decline. In the early stage of onset, sick pigs will definitely show clinical signs. If abnormal pigs are found, they should be isolated and diagnosed immediately, and the pigsty should be thoroughly disinfected to eliminate the disease in its early stages.
2.2 Pay Attention to Pigsty Environmental Management
Due to unstable weather in early spring, the temperature and humidity difference between day and night is significant. If pigsties are opened too early, pigs will inevitably experience discomfort. In the early stages, it is best to continue using artificial control of pigsty temperature and humidity. Only when the average temperature remains above 15℃ for a continuous week should the ventilation gradually be increased. Because pigs have no sweat glands on their body surface, their body heat entirely relies on heat exchange and radiation between the body surface and the environment. Changes in environmental temperature and humidity have a significant impact on them. Therefore, in spring, it is crucial to control environmental conditions well so that the pig herd gradually adapts to the new season.
2.3 Pay Attention to Stress Responses
There are many stress factors that affect pig production, including weaning, regrouping, temperature changes, fighting, changing feed, changing caregivers, long-distance transportation, and noise stress. Any external factor that too quickly changes the existing behavioral habits of pigs and causes maladaptive responses in their bodies can be called a stress response. Although stress does not directly cause disease, it can become an inducing factor for disease occurrence. This is because most pigs have conditionally pathogenic bacteria in their bodies. Under stress, the pig’s body resistance temporarily declines, providing an opportunity for these conditionally pathogenic bacteria to invade and cause disease. Therefore, spring pig farming must focus on management and make every effort to reduce the occurrence of stress.
3. Key Points for Prevention and Control
3.1 Prevention and Control of Viral Diseases
For viral diseases, it is essential to do a good job in basic vaccine immunization. The emphasis on viral vaccines is because, firstly, the pathogenesis of viruses is unique. Most viral infections require cell-mediated immunity to be completely cleared, but cell-mediated immunity can damage the infected tissues and organs. Therefore, early vaccination allows the body to produce effective antibody titers. Even if infection occurs, the pathogens can be quickly phagocytosed and killed through humoral immunity without progressing to the cell-mediated immunity process, providing the best protection for the body.
Secondly, most basic viral vaccine production technologies are very mature and safe to use. Even if pig farms adopt a “one-size-fits-all” whole-herd immunization approach, the stress on the overall pig herd is not significant. Early immunization leads to early benefits. Thirdly, once viral diseases occur, there are currently no specific antiviral drugs. Common chemical antiviral drugs are largely ineffective, and their use can easily lead to food safety issues, affecting human health. Therefore, viral diseases require a focus on immune prevention.
3.2 Prevention and Control of Bacterial Diseases
The characteristics of bacteria are different from those of viruses. Bacteria are independent unicellular organisms with their own organelles that can metabolize independently, while viruses must parasitize to replicate. Precisely because the reproduction and metabolic processes of bacteria are more complex than those of viruses in evolution, different types of antibiotic drugs have been developed based on their mechanisms for prevention and control. At the same time, bacteria are easily cultured in vitro, and drug sensitivity tests can be used to screen drugs. Most bacterial diseases can be prevented and controlled with antibiotics even if they occur. Therefore, the prevention and control of bacterial diseases are somewhat easier than those of viral diseases.
3.3 Prevention and Control of Molds
Molds are classified as eukaryotes, which are much more advanced than viruses and bacteria. The optimal growth temperature for most molds is 28℃, and the higher the humidity, the faster they reproduce. In winter, most areas have cold weather and low humidity, so molds are basically dormant. After spring arrives, the weather warms up, and the humidity also increases correspondingly, making mold reproduction more active. Pig farms are places where mold often grows, especially in feed, which is rich in nutrients and very suitable as a culture medium. Clinically, mold poisoning is not caused by the mold itself, but by the toxins produced during its reproduction and metabolism. These mainly include aflatoxin, zearalenone, F2 toxin, ochratoxin, T2 toxin, vomitoxin, etc. In the production process, it is essential to use mold inhibitors to reduce toxin absorption and properly store feed to avoid mold growth during storage and subsequent animal poisoning.