Disease Occurrence Patterns and Prevention Methods for Pigs at Different Rearing Stages

Disease Occurrence in Pigs at Different Rearing Stages

Incidence Rates of the Three Major Infectious Diseases of Pigs

Hog cholera, swine erysipelas, and swine pasteurellosis are collectively known as the three major infectious diseases of pigs. In China, the overall mortality rate of affected pigs accounts for about 8% of the total reared population, and even in areas with relatively good prevention and control, pig mortality stands at 5%. Therefore, the level of pig disease prevention and treatment should be improved. If the overall pig mortality rate could be reduced by one percentage point each year, that would be equivalent to an additional 5 million pigs sent to market - what a tremendous amount of wealth that represents.

According to relevant statistics, among the causes of pig deaths, those caused by disease account for over 80%, and among all pig diseases, infectious diseases account for about 70%-80%, of which hog cholera, swine erysipelas, and swine pasteurellosis alone account for 70% of pig infectious diseases. Therefore, in pig disease prevention and treatment, the control of these three diseases has become the top priority.

Since the attenuated hog cholera vaccine developed in China is one of the world's most advanced vaccines, the preventive effects of the hog cholera vaccine, the hog cholera-swine erysipelas bivalent vaccine, and the hog cholera-swine erysipelas-swine pasteurellosis trivalent vaccine produced by designated pharmaceutical factories in China are all relatively reliable. In areas that follow scientific immunization procedures and maintain scientific vaccination coverage, these three diseases can all be effectively controlled. However, in some areas, the grassroots veterinary epidemic prevention teams are unstable, and pig vaccination coverage cannot be guaranteed. In some areas, immunization procedures cannot keep up with @#@227@#@ changing circumstances, and cases still occur after vaccination; in some areas, atypical hog cholera occurs; in some areas, long-term use of the bivalent vaccine has led to sporadic outbreaks of swine pasteurellosis, causing undue losses to the local pig industry.

Disease Prevention and Treatment at the Piglet Stage

The mortality rate of piglets from various causes at 1-2 weeks after birth accounts for 65% of the entire piglet stage (from birth to 1-2 weeks after weaning), and the mortality rate at the piglet stage accounts for 70% of the lifetime mortality rate of pigs. This shows the importance of feeding management and disease prevention at the piglet stage.

1. Disease occurrence is related to feeding management. If newborn piglets are not properly kept warm, they are highly susceptible to colds, diarrhea, and even death (such as piglets huddling together from cold leading to crushing deaths or injuries); failure to supplement calcium in time can lead to anemia and indigestion in piglets.

2. Piglet red diarrhea, yellow diarrhea, white diarrhea, piglet paratyphoid, edema disease, etc. mostly occur at this stage, and the causes of these diseases are roughly as follows:

(1) Low maternal antibody titer or absence of maternal antibodies;

(2) Poor health status of the sow;

(3) Poor sanitary conditions in the pig house;

(4) Piglets not vaccinated according to relevant disease immunization procedures or not given relevant drug prophylaxis.

3. The growth rate at the piglet stage, especially the survival rate at weaning and weaning litter weight, are important indicators for measuring the breeding efficiency of a pig farm. At the piglet stage, once a piglet becomes ill, even if it recovers after treatment, it will still have a great impact on its growth during the fattening stage, and some may become stunted pigs as a result.

Disease Prevention and Treatment Should Be Prioritized

1. In disease prevention, priorities should be established. For infectious diseases such as piglet colibacillosis, hog cholera, swine erysipelas, swine pasteurellosis, piglet paratyphoid, streptococcosis, and enzootic pneumonia, most currently have vaccines (bacterins), and vaccination should be carried out according to their respective immunization procedures, avoiding the time of cross-stress from immunization.

2. In disease treatment, priorities should be established. When infectious diseases and common diseases occur simultaneously, infectious diseases should take priority; when two infectious diseases occur simultaneously, virulent infectious diseases and zoonoses should take priority; when secondary infections occur (such as complications caused by influenza), differential diagnosis must be applied.

Diseases of Pigs at Different Rearing Stages

Piglet stage (from birth to 1-2 weeks after weaning)

This period is a critical time for pig growth. Most infectious diseases, some parasitic diseases, and nutritional deficiency diseases caused by improper feeding management can all pose a threat to piglets and cause disease. Many diseases can cause direct death of piglets. Common ones include the following:

Piglet red diarrhea mostly occurs in piglets within 1 week of age.

Piglet white diarrhea has a high incidence rate in newborn piglets.

Piglet edema disease mostly occurs in piglets from 40 days to 70 days of age; it rarely occurs in suckling pigs within 10 days of age, but recently there has been a trend of increasing age of onset.

Hog cholera can infect suckling pigs and piglets before and after weaning, and the younger the affected pig, the faster the death.

Swine erysipelas is mostly caused by disease in the sow.

Swine pasteurellosis rarely occurs in suckling pigs; piglets after weaning can become infected and develop the disease during epidemic periods.

Piglet susceptibility to swine streptococcosis is high, and the septicemic form often leads to rapid death of piglets.

Piglet paratyphoid mostly occurs in unvaccinated piglets from 2 months to 4 months of age, and rarely occurs in piglets within 1 month of age.

Swine influenza has a low incidence rate in piglets, and the incidence rate increases in weaned piglets.

Haemophilus parasuis disease often occurs secondary to influenza infection in pigs.

Congenital tremors in piglets: this disease occurs sporadically in some areas, often affecting entire litters, and newborn pigs are often starved or crushed to death.

Foot-and-mouth disease in pigs: infected young pigs have a very high mortality rate. Suckling pigs infected with this disease often show no blister symptoms and die from acute gastroenteritis or myocarditis.

Transmissible gastroenteritis has a high lethality rate in piglets within 10 days of age.

Swine lungworm disease: piglets infected before weaning can die in large numbers.

Swine ascariasis: suckling pigs can be infected from 1 week of age onward.

Swine cysticercosis: piglets can be infected in epidemic areas, but clinical symptoms rarely appear.

Piglet anemia is one of the common and frequently occurring diseases in suckling piglets from 2 to 4 weeks of age; pigs affected from 3 to 10 days of age may die suddenly.

Rickets (osteomalacia) is caused by calcium and phosphorus deficiency or imbalance, of which congenital rickets is caused by poor bone development in piglet embryos due to nutritional deficiency in the sow.

Fattening stage (feeder pigs - finishing pigs)

The fattening stage is another critical stage in the growth of pigs (commercial pigs). During this period, as pigs grow at their fastest rate, various diseases also follow one after another. Whether they are common and frequently occurring infectious diseases, parasitic diseases, or metabolic diseases and poisoning diseases, they are all issues that pig farms of various scales must take seriously, and various prevention and treatment measures must be implemented.

Among the common and frequently occurring diseases at the piglet stage, apart from yellow and white diarrhea caused by E. coli, edema disease, paratyphoid, piglet anemia, and rickets, most of the remaining infectious diseases and parasitic diseases can also be contracted during the fattening stage, and the incidence rates far exceed those at the piglet stage, posing a great threat to the pig industry.

In addition to the common and frequently occurring diseases at the piglet stage, almost all pig infectious diseases, parasitic diseases, metabolic diseases, and poisoning diseases can be contracted or occur during the fattening stage. Therefore, every pig farm must formulate disease prevention and control systems and measures suited to its actual situation.

1. Carry out immunization against infectious diseases according to procedures. For newly purchased weaned piglets, their vaccination status should be carefully investigated, and necessary supplementary vaccination (such as bivalent vaccine, trivalent vaccine) should be carried out; for some seasonally occurring infectious diseases, the pig herd should be immunized one month in advance; for infectious diseases for which no effective vaccine currently exists, drug prophylaxis should be carried out 15 days in advance.

2. Regular deworming with drugs. Parasitic diseases are extremely harmful to fattening pigs. In addition to intestinal parasites, swine cysticercosis and toxoplasmosis are both zoonoses, among which toxoplasmosis can also cause seasonal and regional epidemics. Most parasitic diseases currently have no effective vaccine, so regular deworming and prevention through drugs are necessary. Manure from pig farms should be piled up and fermented, using biological heat to kill parasite eggs.

3. Prevent common diseases by strengthening feeding management. Many common diseases such as trace element deficiency, vitamin deficiency, and poisoning diseases can be completely prevented by feeding high-quality complete compound feed. Therefore, the nutrition and hygiene of feed and drinking water should be strengthened.

4. Some infectious diseases can be prevented by adding drugs. Currently, there are no effective vaccines for preventing some pig infectious diseases, such as swine influenza, Haemophilus parasuis disease, viral diarrhea, and swine dysentery. There are some Chinese herbal compound powders and fine powders on the market that can be mixed into feed for prevention and treatment, and some Chinese herbal powders also have growth-promoting effects.

5. Observe strict hygiene and disinfection systems. The pens of intensive pig farms, due to good facilities and conditions, are easy to clean and disinfect. The pens of free-range farmers have poor sanitary conditions, so they must be cleaned frequently and fresh soil must be added frequently, manure must be piled up and fermented, pens must be regularly sprayed with disinfectants, and the roofs, inner and outer walls, and passages of the pens must be thoroughly disinfected regularly.