Study On Biological Characteristics Of Clinical Strains Of Eimeria Tenella

Eimeria coccidiosis caused by chicken coccidiosis is a parasitic disease that seriously damages the poultry industry.Eimeria tenella belongs to the most pathogenic type and is in the intensive chicken farm.The high prevalence has a significant impact on chicken growth and feed conversion rates.This experiment isolated and identified the Eimeria tenella isolates in the Boluo district of Guangdong,and the size,shape index,latent period,fertility,pathogenicity,drug resistance,and immunogenicity of the isolates.Sex research was conducted to lay a theoretical foundation for the effective prevention and control of Eimeria tenella in the Boro area of Guangdong.In the first part of this study,we studied the biological characteristics of coccidia,a clinical isolate of soft Eimeria.The results showed that the average size of the oocysts was22.46?m×18.82?m,the oocyst shape index was 1.19,and the latent period was 116 h;Spore oocysts infecting 7-day-old chickens had a peak ovulation time of 168-192 hours.After reproduction,3.04×10~8 oocysts were produced.The reproduction index of each oocyst was 3000;the pathogenicity was studied and 48 individuals were selected.Day-old chickens were evenly divided into 6 groups.They were infected with E.sinensis larvae.The strains were 0,5,000?10,000?30,000?50,000?100,000/feathers.The results showed that the higher the infection dose,the more serious the disease was.Infected with 1×10~5/feathers was the most serious,and the infection dose began to be 5×10~4/feathers,causing chickens to die.The diseased chickens were dissected and examined,and there was no normal contents in the intestine.The cecal appearance was more common and the caecum intestine was swollen.There are a large n?mber of bloody intestine cores,thickening of the cecum wall and bleeding points.Using specific PCR methods to further molecular identification,the results confirmed that the isolated coccidia oocysts were pure Eimeria tenellas and were not infected with other species of coccidia.In the second part of this study,evaluates the drug sensitivity of Eimeria tenella.The fifty-six of 14-day-old chickens were evenly divided into 7 groups.Five drug groups,one no-drug control group,and one non-infectious drug control group were set up to reduce the score of intestinal lesions.The scores of bloody stools and the index of anticoccidial were used as indexes to comprehensively evaluate the strain E.tenella on Toxopril,deoxyquinoline,salinomycin,maduramycin,sulfachloropyrazine sodium,etc.Resistance to five commonly used anticoccidial drugs.The results showed that the anticoccidial drugs decoquinate and sulfachloropyrazine sodium were sensitive,and toltrazuril,salinomycin and maduramycin were partially resistant..In the third part of this study,evaluates the immunogenicity of E.tenella.using the isolate as an immunizing strain,blood-stool score,survival rate and lesion scores,fecal OPG,and anticoccidial index(ACI)as evaluation indicators.The results showed that all immunization groups had a certain level of immune protection,of which the one hundred thirty immune oocysts/feather anti-coccidial index was 192.27,which had the best immune effect.