| To understand the parasite infection situation,influencing factors and dominant parasite species evolution of Elaphurus davidianus in Beijing Nanhaizi Milu Park,the veterinary health status of Elaphurus davidianus,the parasite eggs in deer faeces and in activity area soil,and medical mollusc of the water in the park were investigated by retrospective investigation,worm body examination,the saturated salt water float method,precipitation accumulation,egg detection and counting of flake-shaped trematode and the improved anti-acid staining.In addition,the molecular system analysis of the deer dominant parasite species was carried out.The results showed that:(1)From 2018 to 2019,the total parasite infection rate of the deer in Nanhaizi Milu Park was82.76%~100%.And the infected parasites were mainly nematodes,trematodes,tapeworm and protozoa.Which the infection rate decreased in turn.Among them,nematodes and trematodes were predominant.Besides,there were mixed parasites infections of two,three and four types.The average intensity of parasite infection in the deer faeces samples in spring 2018 was 2586 parasite eggs per gram,what was15.67 parasite eggs per gram in autumn 2018 and in autumn 2019 was 14.32 parasite eggs per gram.It indicated that there was widespread parasite infection among Elaphurus davidianus in Beijing Milu park,which was severer in spring than in autumn.(2)The mian parasite species of Elaphurus davidianus in Beijing Nanhaizi Milu Park were Haemonchus egg,Trichostrongylus egg,Ascaridoidea egg,Ancylostomatidae egg,Taenia egg and Balantidium coli.Which the Haemonchus and Trichostrongylus eggs were predominant.The homology of ITS-2 gene that the Haemonchus spp.isolated from this study to several isolates of Haemonchus contortus in Gen Bank were 97.8%~99.6%.So,the isolate of Haemonchus spp.in this study was identified as H.contortus.Comparing all sequences of the phylogenetic tree,the genetic distance between the H.contortus isolate identified in this study and those from Australian cattle and Indian goat were 0(minimum),and they located on the same branch in the phylogenetic tree.Besides,the homology of ITS-1 gene that the Trichostrongylus spp isolated from this study to several isolates of Trichostrongylus colubriformis in Gen Bank were 92.9%~94.1%.Therefore,the isolate of Trichostrongylus spp in this study was identified as T.colubriformis.The genetic distance between the T.colubriformis isolated from this study and that from Indian sheep was the smallest(0.025),and the genetic relationship between them was the closest in all sequences of phylogenetic tree.(3)In the deep soil of the Nanhaizi Milu Park activity area,90~95 cm,the detection rate of parasite eggs was 100%,which was higher than that in the middle soil(30~35 cm)and shallow surface layer(2~7cm)by 67%.Which the main eggs detected were Ascaridoidea eggs,Trichuris trichura eggs and Taenia eggs.It indicated that the number of parasite eggs in deep soil was more than that in the middle and shallow surface layers.(4)In the water and silt of the park,the detection rate of medical mollusc was 100% in the silt.Three kinds of medical mollusc were detected,of which the main was Bellamya Jousseaume,which could be the intermediate host of Angiostrongylus cantonensis,Clonorchis sinensis and Echinotrematodes.(5)Parasite infection was closely related to the living environment among Elaphurus davidianus in Milu park.The main factors that affected the prevalence of parasite were insufficient deinsectization and rotational grazing,no harmless treatment of faeces and water,and the eggs discharged with faeces became an important factor of circulating infection.Therefore,the park should strengthen the regular monitoring of the parasites,reduce the feeding density,and carry out the harmless treatment of the activity area soil and water in the park on a regular basis,so as to reduce the parasite infection and ensure the healthy development of Elaphurus davidianus population. |
PDF Full Text Request