Experimental Infection of Sheep using Infective Larvae (L3) harvested from the Faeces of Naturally Infected Swayne’s Hartebeest (<i>Alcelaphus buselaphus swaynei</i>) at Senkele Swayne’s Hartebeest Sanctuary, Ethiopia

Abstract

Experimental infection of sheep using nematode larvae recovered from the faeces of naturally infected endangered Swayne’s Hartebeest (SHB) was carried out from December/2006 - April/2007 to assess the potential for the inter–species transmission of helminths. Faecal samples were collected from Swayne’s Hartebeest without preservatives and cultivated at room temperature for 21 days. Infective larvae were collected overnight by Baermann’s Method and identified and counted under a microscope. The sample was divided into eight aliquots of 9400 infective larvae and drenched into eight worm-free sheep kept at zero grazing. After 30  days, faecal samples from infected sheep were examined for ova for further 30 days by the Modified McMaster Method. Adult nematodes were recovered from the infected sheep at post mortem examination and distinguished based on position of barbs, shape and length of spicule, position of cervical papillae and mouth parts. The mean eggs per gram of faeces (EPG) from all infected sheep was 9192 ± 1422. Haemonchus placei (86.3%) from abomasums, Oespophagostomum venulosum (13.3%) and Trichuris spp (0.3%) from large intestine were identified. No ova and adult parasite were recovered from the control sheep. The study demonstrated that transmission of helminths between Swayne’s Hartebeest and sheep is experimentally possible. This is the first study conducted on the potential inter-species transmission of parasites between Swayne’s Hartebeest and local sheep and fur ther research is recommended to determine the impact of multiple-species habitat use, on pasture contamination and any associated pathological impact.

Key words: Eexperimental infection, helminths, inter-species transmission, local sheep, Swayne’s Hartebeest