Porcine circovirus detection rate as high as 100%: how should pig farms deal with it?
Circovirus, circovirus again! The detection rate on pig farms is actually as high as 100%. How on earth should it be dealt with?
According to relevant statistics, the detection rate of this disease on pig farms is 100%, and its harmfulness can be imagined. The incidence of porcine circovirus disease is so high, yet even now many farmers still have not paid enough attention to it.
In the process of pig production, no matter how the farm is managed, some unpredictable diseases will occur. In particular, the feed nutrition and feeding management levels of some farms and households cannot keep up, and in addition some vaccines are administered in large or excessive doses, and antibiotics are used irrationally, causing the health status and immune function of pigs to decline, and pigs are becoming harder and harder to raise,pig diseasesthe incidence and cure rate are becoming more and more difficult to control, so doing a good job in the prevention and control of circovirus is important work for pig farms.
Porcine circovirus infection can cause immunosuppression in pigs, thereby making the body more susceptible to other pathogens, which is also the reason why circovirus is related to mixed infections with many pig diseases.
The most common mixed infections are circovirus, PRRS, Haemophilus parasuis, and Streptococcus; circovirus, PRRS, and enzootic pneumonia; circovirus, PRRS, enzootic pneumonia, contagious pleuropneumonia, and pseudorabies. The mortality rate of affected pigs can reach as high as 25%-40%.
I. Clinical manifestations:
1. Postweaning multisystemic wasting syndrome
The onset age is 40-60 days or 80-120 days. The most common signs are progressive emaciation or stunted growth in pigs. Anorexia, depression, slow movement, pale skin, rough hair coat, difficulty breathing, and respiratory disorders characterized by coughing. Less commonly found symptoms are diarrhea and central nervous system disorders.
Superficial lymph nodes on the body surface are enlarged; the swollen lymph nodes can sometimes be palpated, especially the superficial inguinal lymph nodes; anemia and jaundice of the visible mucous membranes. The main lesions are mottled lungs, rubbery lungs, and enlarged lymph nodes.
Under factors such as poor ventilation, overcrowding, foul air, mixed rearing, and infection with other pathogens, the condition worsens markedly, and the general mortality rate is 5%-30%.
2. Porcine dermatitis and nephropathy syndrome
The onset age is 50-70 days. Skin erythema or papules, most common on the limbs and abdomen. It can also spread to the chest, lower back, and ears. The morbidity and mortality rates are generally around 1%.
The main lesions are enlarged kidneys with white necrotic foci on the surface.
3. Symptoms of congenital tremors
After birth, the whole body muscles of the piglets tremble, disappearing after lying down or sleeping and recurring after waking. They can recover and survive after one week of suckling. Some pigs cannot recover, and the trembling continues throughout the growing and fattening periods.
Special note: this disease is usually co-infected with Haemophilus parasuis. In clinical necropsy, pleurisy, adhesion of the chest wall, fibrinous exudation, pulmonary hemorrhage (petechial, patchy, confluent), abscesses, pericarditis, increased pericardial fluid, peritonitis, fibrinous exudation in the abdominal cavity, and arthritis are commonly seen.
II.Prevention and controlmeasures:
1. Immunization
On the basis of doing a good job with circovirus vaccination, do a good job with immunization against PRRS (according to the farm's situation), pseudorabies, and enzootic pneumonia.
2. Reduce stress
Industrialized farming methods may be related to this disease. Poor feeding management, a harsh weaning environment, mixing pigs of different sources and ages, excessively high stocking density, and stimulation of the piglets' immune system are all important risk factors inducing this disease.
3. Temperature
When symptoms are found in piglets and growing pigs, the barn temperature should preferably be 25-30°C.
III. Nutrition:
Provide feed with high nutritional value. Feed nursery pigs creep feed and growing pigs nursery feed. Feed small amounts frequently; gruel feed is best, and powdered feed is the worst.Prevention and controlof secondary infections: dehydrated pigs should drink electrolytic multivitamins and rehydration salts.
For congenital tremors, prevent crushing to death, give special care, and ensure every pig gets to suckle, which can reduce the mortality rate.
IV. Management:
Establish and improve the biosafety system of the pig farm, carry out disinfection and hygiene work in every work link, and minimize the pathogenic microorganisms contaminating the pig farm;
Reduce stocking density; foster care of piglets should be limited to within 24 hours after birth; prevent piglets of different sources, different parities, and different ages from being raised together; adopt all-in/all-out for the pig herd; reduce and eliminate secondary infections in the herd, thereby controlling or reducing the chance of piglets being infected with circovirus.