How to Diagnose and Prevent Common Reproductive Disorder Diseases in Small and Medium-Sized Pig Farms (Part 1)
Clinical Diagnosis and Prevention of Common Reproductive Disorder Diseases in Small and Medium-Sized Pig Farms (1)
Abstract: In recent years, with the increase in breeding numbers and the frequent circulation of livestock products, various pig diseases have become increasingly numerous and harmful, especially porcine reproductive disorder diseases, which have become the main factor restricting pig production. Especially in small and medium-sized pig farms, porcine reproductive disorder diseases are widespread, with varying degrees of clinical severity, seriously affecting the sustainable and healthy development of the pig industry. This article analyzes the common and highly harmful porcine reproductive disorder diseases in small and medium-sized pig farms, summarizes the key points of clinical diagnosis, and explores effectiveprevention and treatmentmeasures.
Keywords: pig; reproductive disorders; clinical diagnosis;prevention and treatment
1 Main Characteristics and Causes of Porcine Reproductive Disorder Diseases
Porcine reproductive disorder diseases are mainly characterized by abortion, stillbirth, mummified fetuses, delivery of non-viable weak piglets, malformed piglets, small litters, boar infertility, and sow infertility in pregnant pigs. Any breeding-stagebreeding pigshowing one or more of the above clinical manifestations can be considered to be suffering from a reproductive disorder disease.
There are many causes of porcine reproductive disorders, mainly divided into infectious factors and non-infectious factors. Infectious factors include: viral diseases, bacterial diseases, and parasitic diseases; non-infectious factors include: incomplete development of the pig body, malnutrition, poisoning, stress, poor feeding and management, and unreasonable breeding systems (such as excessive inbreeding), etc. Under large-scale farming models, reproductive disorder diseases caused by non-infectious factors are relatively fewer, and most are caused by infectious factors, which are more harmful,prevention and treatmentis also more difficult.
2 Clinical Diagnosis of Common Porcine Reproductive Disorder Diseases
2.1 Porcine Reproductive and Respiratory Syndrome
It is mainly seen in sows that are more than 100 days into gestation. Sows experience large-scale abortion or premature delivery, giving birth to stillborn, weak, or mummified fetuses. Most sows show respiratory symptoms of varying degrees such as sneezing and coughing. Some sows may have a slightly elevated body temperature, but usually do not have persistent high fever. Severe cases may show depression, difficulty breathing, cyanosis of the ear tips, edema at the extremities and ventral sides, and swelling of the vulva. Infected breeding boars develop high fever, temporary reduction in semen volume and decreased semen quality; infected piglets show elevated body temperature, difficulty breathing, ataxia, cyanosis of the ear and nose tips and body extremities, and stunted growth. The mortality rate of pre-weaning piglets can reach 30%~50%.
The virus mainly attacks the lungs. Gross necropsy of cases shows pulmonary edema, hemorrhage, and congestion, with focal to diffuse yellowish-brown or brown consolidation mainly in the cardiac and apical lobes; enlarged heart with myocardial hemorrhage and necrosis, and in severe cases the myocardium may become soft; uneven liver color with mild congestion and a small amount of spotted hemorrhage on the surface; enlarged spleen with purple hemorrhagic foci; fragile kidney texture with numerous petechial hemorrhages on the surface; enlarged lymph nodes; hemorrhagic and suppurative tonsils.
2.2 Porcine Pseudorabies
Infected pregnant sows show abortion, giving birth to stillborn and mummified fetuses; piglets show high fever, complete loss of appetite, difficulty breathing, followed by neurological symptoms and death. The mortality rate of piglets within 15 days of age is 100%, and the mortality rate of weaned piglets reaches 10%~20%; after feeder pigs are infected, symptoms are mild, with fever and coughing, and they recover in 3d~4d; adult pigs only show slow weight gain with no obvious symptoms.