2. Reasons for introduction and improvement of varieties.
Local breeds of pigs have many advantages, such as adaptability to local environment and strong local resistance. These advantages are formed through several generations of evolution in the local area. Once they leave the local area and change the environment, these advantages may weaken or even disappear.
The introduction and improvement of farmers is to introduce foreign and foreign varieties of pigs into local hybridization to produce offspring, and their resistance is not as strong as that of local varieties of pigs.
3. Reasons for convenient transportation
Modern traffic conditions are conducive to the exchange and trading of materials, livestock and livestock products, but at the same time, it also brings the prevalence of some endemic infectious diseases. The endemic epidemic is not harmful in the local area, but once it is introduced to other areas, it may cause an epidemic.
4, health and epidemic prevention system is not perfect, the implementation is not in place.
During the purchase, transportation and introduction of live pigs, due to various reasons, the epidemic disease inspection was not strictly carried out in accordance with the regulations of the animal husbandry department, and there was even a phenomenon of "billing when paying money", which made infectious diseases popular and caused diseases.
5. Reasons for the existence of various diseases.
Due to inadequate preventive measures and incomplete immunization procedures, some old infectious diseases have not been eliminated, and new infectious diseases have occurred one after another, such as chronic swine fever, Pasteurella multocida and streptococcus. , as well as respiratory and reproductive disorders, nameless high fever, Haemophilus parasuis, eperythrozoonosis and so on in recent years. It appears again, which is easy to cause mixed infection in pigs.
6. Causes of abuse of antibiotics
As there are more and more diseases in pigs, farmers have to use some antibiotics to prevent and treat diseases. Due to the extensive use of antibiotics, pathogens are resistant and bacteria are resistant, resulting in drug-resistant strains, which can not achieve the therapeutic effect and aggravate the condition.
Although there are many kinds of pig diseases and the situation is complicated, some specific clinical symptoms or pathological changes can be used as indicators of the disease. Now I would like to introduce the common and representative points of pig disease identification: the points of common diseases identification.
1, Differentiation between Hot Epidemic and Skin Erythema
(1) The pharynx is obviously swollen, showing an acute course-porcine pneumonia.
(2) The obvious swelling of pharynx is a chronic process-swine anthrax.
(3) There is no swelling of the pharynx at all ages, and erythema and finger pressure do not subside-classical swine fever.
(4) At 6 months old, there is no pharyngeal swelling, erythema finger pressure does not subside, erythema does not protrude from the skin, and the boundary is unclear, which is easy to cause toxoplasmosis in pigs.
(5) There is no swelling in the pharynx, and it is easy to get sick when it is 6 months old. Erythema subsides, erythema protrudes from the skin, and there are obvious boundaries such as rhombic and square erysipelas.
(6) No pharyngeal swelling mostly occurs in the limbs of piglets, with claudication and neurological symptoms-Streptococcus suis.