Investigation And Control Measures Of Parasitic Infection In Digestive Tract Of Large-scale House Fed Sheep In Henan And Other Places

Parasitic diseases is one of common diseases in sheep industry,which is dangerous in lambs and can even lead death.Most of adult sheep are subclinical-infected,which affects the development of sheep industry.In this study,a combination of morphology and molecular biology was used to identify parasites,aiming to provide a scientific basis for rational prevention and control of parasitic diseases in large-scale sheep feeding.1.To realize the status of parasitic infections in confined sheep in different regions and physiological stages,721 sheep fecal samples and 396 environmental samples collected from Henan Province,Jiangxi Province,Shanxi Province,Ningxia Hui Autonomous Region,Inner Mongolia Autonomous Region and Tianjin City,were examined microscopically by applying centrifugal sedimentation,Lugol’s iodine solution staining,saturated sucrose solution floating method and Mc Master’s counting method.The results showed that the total fecal parasitic infection rate was 86.41%(623/721)and the total environmental parasitic detection rate was 23.23%(92/396).7 species(classes)of GI parasites,including Eimeria spp.,Entamoeba spp.,Trichuris spp.,Nematodirus spp.,Tapeworm spp.,Cryptosporidium and Giardia were detected.Among these,Eimeria spp.and Entamoeba spp.were the dominant species and the infection rates were 70.59%(509/721)and 61.03%(440/721),respectively.The total infection rate of Coccidia in sheep in Tianjin and Shanxi provinces were the highest at 100%(33/33,19/19),while the total infection rate in Inner Mongolia Autonomous Region was the lowest at 83.33%(30/36).The survey of sheep at 9 different physiological stages revealed that the parasite infection rate was as high as 100% in sheep at 4-6 months of age sheep and 7-12 months of age;the lowest parasitic infection rate was 42.53%(37/87)in 20 days lactating lambs.Based on the survey results and the problems of sheep farms’ deworming measures,we proposed better deworming measures.2.To realize the difference of sheep coccidia species at different physiological stages,311 coccidia-positive samples were morphologically identified.12 Eimeria spp.were identified,of which E.ovinoidalis was the dominant species with the infection rate of 26.02%(102/392).The dominant coccidia species in sheep at 4-6 months of age and one week before parturition was E.faurei,the dominant coccidia species in sheep at 7-12 months of age,ewes at 3 months of pregnancy and lactating ewes was E.ovinoidalis,the dominant coccidia species in empty ewes was E.faurei,and the dominant coccidia species in breeding rams was E.bakuensis.3.To realize the prevalence of Cryptosporidium in sheep in different seasons and physiological stages,a total of 486 fecal samples and 324 environmental samples were collected.The whole-genome DNA of samples was extracted and detected by nested PCR based on SSU r RNA loci.The results showed that Cryptosporidium was not detected in environmental samples;the infection rate of Cryptosporidium in sheep was 2.06%(10/486).And the infection rates in spring,summer,autumn and winter were 1.48%(2/486),1.89%(2/486),2.33%(3/486)and 2.59%(3/486),respectively,which had no significant difference.Cryptosporidium was detected only in 20 days old lactating lambs,1-3 months old sheep,and 4-6 months old sheep,with the highest infection rate of 10.77%(7/65)in 1-3 months old sheep.C.ubiquitum and C.xiaoi were totally detected,which infection rates were 0.62%(3/486)and 1.44%(7/486),respectively.The results showed that Cryptosporidium was not detected in environmental samples;the total infection rate of Cryptosporidium in sheep was lower,while there were zoonotic Cryptosporidium spp.,which had a potential zoonotic risk.4.Based on the above results,and the practice and effect of prevention and control of fulminant lamb coccidiosis,combined with the problems existing in the original epidemic prevention and deworming procedures of the sheep farm under investigation,a relatively complete large-scale sheep epidemic prevention and deworming plan for sheep farms was studied and formulated.