The Survey Of Infection Status Of Intestinal Parasites And Toxoplasma Gondii In Pigs On Large-scale Farms In Dafeng

Porcine parasitic diseases are the chronic consumptive diseases,which are common in pig production and are caused by a wide variety of parasites.Among them,pig intestinal parasites are the most widespread and most severe.The vast majority of infected pigs lack the typical symptoms and the mortality rate is relatively low,however,the infection rate is very high.The intestinal parasites can reduce daily weight gain and the carcass quality,hinder growth and development,reduce immunity.Serious infection can cause weight loss,anemia,reduction of feed conversion,premature birth or miscarriage in pregnant pigs,and even death.And some parasites are zoonosis,which poses a great threat to human health and life safety.Prevalence of parasitic diseases in hosts are closely not only related to life history of parasites,but also the methods of animal feeding and management.At present,pig industry has gradually been developed into the large-scale,intensive and closed farming model in China.Impact of the change of feeding pattern on parasitic diseases in swine need to be investigated and analyzed.Therefore,the aims of this study were to determine the prevalence of intestinal parasites and toxoplasmosis in pigs on large-scale farms in Dafeng region,Jiangsu Province.This investigation not only enrichs the epidemiological data of parasitic diseases in pigs in large-scale,intensive and closed farming model,but also provides the data support for the prevention and control of parasitic diseases in large-scale pig farms.1.The epidemiological investigation of intestinal parasites in pigs on large-scale farms in Dafeng regionA total of 538 samples of pig feces were collected from different farms in Dafeng region,Jiangsu Province,and then were examined using sedimentation and saturated flotation methods,respectively.The results showed that the total infection rate of intestinal parasites in pigs was 11.71%(63/538),and Balantidium coli and the oocysts of Isospora suis were found in this survey.The infection rates of B,coli and I.suis were 7.62%(41/538)and 4.09%(22/538),respectively.The Chi-square test analysis showed that the ages and the seasons were the important risk factors for B.coli and I.suis infections in pigs.2.Investigation on the status of cryptosporidosis infection in pigs on large-scale farms in Dafeng regionA total of 300 fresh feces of 7 to 15 days old piglets were collected from large-scale farms in Dafeng region,Jiangsu Province.After extracting the DNA from fecal samples,a nested PCR was performed using two pairs of specific primers.The results showed that the positive rate of Cryptosporidium was 13.67%(41/300).After PCR products purified and then ligated with the pGEM-T Easy vectors,the recombinant vectors were cloned and sequenced.The sequence analysis showed that the sequence had the highest homology with Cryptosporidium struthioni.Also,the phylogenetic tree analysis confirmed that the obtained Cryptosporidium belonged to Cryptosporidium struthioni.This sequence was named C.struthionis CS-JS-1 and was submitted to GenBank with the accession number MH449666.3.Epidemiological investigation and analysis of toxoplasmosis in pig on large-scale farms in Dafeng regionA total of 161 blood samples of pigs on large-scale farms were collected from Dafeng region.The anti-T.gondii antibody in serum and T.gondii-specific gene in blood DNA samples were detected by IHA test and PCR method,respectively.The results showed that the comprehensive positive rate of T.gondii infection in large-scale farms of this region was 6.83%(11/161).Among them,the sows have the highest positive rate,while the weaned pigs have the lowest positive rate.The IHA test showed that the average positive rate for T.gondii was 5.59%(9/161),and the PCR method showed that only two DNA samples were amplified successfully with a 531 bp PCR product.And using this method,the positive rate was 1.24%(2/161).These results indicated that the infection of T.gondii in the large-scale pig farms in the region was mainly chronic infection or latent infection.And also,the PCR results showed that the pigs have been suffering the early infection of T.gondii.