| Porcine respiratory disease complex (PRDC) is an important infection disease in pig industry with large economic lose, and caused by several pathogens including Mycoplasma hyopneumia (MID, Porcine reproductive and respiratory syndrome virus (PRRSV), Actinobacillus pleuropneumoniae (APP), Pseudorabies virus (PRV) , Porcine influenza virus (PIV) , Porcine circovirus type 2 (PCV-2) , Hog cholera virus(HCV) and Porcine respiratory coronavirus (PRCV) etc.. Some pathogens of parasite and environmental stress may also take place in this infection disease. PRDC could be prevented and controlled by seting up scientifical immune procedure, feeding balance nutrition, regular disinfection and using antibiotics.43 clinical tissue samples, which were collected from experimental farms in LuXia, were detected for PRRSV, PRV, PIV, PCV-2 , HCV and PPV by PCR and ELISA antibody technique. In all of 43 samples, 28 samples(65.12%) were detected different virus and 11 samples were co-infectioned by two or more kinds of viruses. The positive rate of HCV, PRRSV, PCV2, PPV, PRV and PIV were 27.9%(12/43), 18.6%(8/43), 20.93%(9/43), 20.93%(9/43), 2.33%(1/43)and 2.33%(1/43)respectively. The results showed that the pigs were mainly infected or coinfected by HCV, PRRSV, PCV-2 and PPV in farms. Forty three serum samples of piglets and 27 serum samples of sows were collected and detected for the antibodies against the viruses as above by ELISA kit. The rates of over positive standard of the vaccined antibodies against HCV and PRV in piglets were 86.05%(37/43)and 89.05%(39/43)respectively. The antibodies stimulated by wild strains of PRV, PRRSV and HCV were detected, and the positive rates were 33.33%(9/27), 59.26%(16/27)and 7.41%(2/27)respectively. The results showed that latent infection (or persistent infection) with wild strains of HCV, PRRSV and PRV in sows was severe. Forteen underground water samples were detected for the total of bacterial flora and the total of E.coli flora, all of them surpassed the sct standard. The highest total of bacterial flora was 7400 cfu/mL, the sum total of E.coli flora reached 1600 cfu/mL. The results showed that water environment was heavy pollutioned.According to the results of epidcmiological study, a comprchcnsivc measure was set up to prevent and control PRDC, including seting up scientific immuny progress, improving conditions of culture and administration, doing a good job of control of small enviromcnt in farms, making regular disinfection and using antibiotics. The proportion of life-newborn piglets increased from 84.15%(3838/4561)(before test)to 92.13%(3303/3585)(after test)(P＜0.01). The mortality of sucking piglets in sucking period decreased from 23.84%(915/3838)(before test)to 7.81%(258/3303)(after test), descended 16.03%(P＜0.01). The mortality of nursery pigs in nursery period decreased from 18.51%(541/2923)(before test)to 7.06%(215/3045)(after test), descended 11.45%(P＜0.01). The test results indicated that the measures,as noted above, could effectively prevent and control PRDC. |
