The Epidemiological Investigation And Prevention Efficacy Of Ileitis In Large Scale Pig Farms In Guangdong

Porcine proliferative enteritis known as necrotic ileitis, is a contact intestinal infectious disease of pigs caused by Lawsoniaintracellularis?LI?, manifested as acute, chronic and sub-clinical different syndromes. Histopathological observed shows that the disease was characterized microscopically by thickening of the intestinal mucosa, intestinal wall cells adenomatous hyperplasia. Mucosal thickening generally takes place at the end of the small intestine, when infected severely or continues for a long time, injury of intestinal hyperplasia will be extended to the colon or caecum.At present, the main methods are used in diagnosis of ileitis: vivo pathology diagnosis, through PCR, immune peroxidase test to detect LI in fecal samples or using IFA, ELISA to detect the antibody of LI. It's difficult to develope a control schedule for ileitis as which often occurs in growth fattening stage, and medication schedule and disease control schedule of each farm is not the same, thus the incidence and time of ileitis is different. So, a simple, accurate method for assessing farm ileitis infection and the time of infection is needed to provide guidance to production and disease prevention and control.For studying the prevalence of ileitis in some pig farms in Guangdong, from 2009 to 2014, fecal samples of 20 large-scale pig farms in Guangdong were detected for LI by use of ileitis LawsoniaFIRSTtest^TM diagnostic kits. In order to understand the infection rate, the infection time, the incidence of LI, provide proper medication schedule or vaccine program to the farm to control the disease. 724 samples were detected, among which 403 samples were positive, the positive rate was 55.66%.The infection rate are not the same during different stages. In early nursery stage, the infection rate was 22.93% and up to 45.06% in the late nursery stage, 69.15% at growth house, 70.58% finishing house. There is no obvious clinical symptom and acute infection is rare in many of the tested farms, most are chronic and subclinical. At the late stage of Nursery and the early period of growth, there was the peak of LI infection, the main reason may be due to the drop of maternal antibodies and mix-group stress. There is much higher subclinical infections in the fattening period, gilts and sows, without showing clinical symptoms, and that's why ileitis infection ratio is high and difficult to control in pig farm.It's better to understand the incidence rule, peak infection of LI before setting up the schedule of prevention and control. Taking reasonable measures 2 weeks before the outbreak of LI, which not only decrease intestinal damage from disease, but also is good and safe for the entire production period. When making prevention and control program of ileitis, the farm should pay more attention to bio-safety and management, supplemented by vaccine and medicine. When choosing the right drugs, focusing on drug sensitivity, pharmacokinetics and drug intervention, medication cycle time in order to control ileitis well. In the conventional drug prevention and control program, Tiamulin and Tylosinoriented program brings more prominent economic benefits, can bring more help to production, produce more economic benefits.