title: Effect of treatment of the ewes on parasitic gastro-enteritis at Easter Bush
title: The effect of treatment of the ewes on parasitic gastro-enteritis at Easter Bush
titleType: AlternativeTitle
Creators: name: Singh, Deo Raj
Publisher: name: The University of Edinburgh
Year: 1976
Subjects: subject: Annexe MSc Digitisation Project 2022 Block 37

description: This project was carried out to investigate the effect of subcutaneous injection of levamisole in ewes six weeks prior to lambing, on the peri-parturient rise in helminth egg counts and the liveweight gains of their lambs up to 38 days of age. Twenty-three Suffolk ewes were randomly allocated to four groups, two of which were kept indoors prior to lambing to protect the lambs after birth from the cold weather during winter. The remaining two groups were kept on pasture throughout the trial. Faecal samples were collected from each ewe at fortnightly intervals from the 21st November, 1975 until the 10th March, 1976. These samples were examined for nematode eggs and cultured for recovery and identification of infective larvae. One group of ewes kept indoors and one group of ewes kept on pasture were treated subcutaneously with six ml of levamisole (levamisole hydrochloride, I.C.I., 7.5 per cent W/V) on 21st November, 1975 after the collection of the first batch of faecal samples from each ewe for worm egg counts. Relatively low levels of nematode eggs were recorded from the two treated groups during most of the period of study. Ostertagia spp. was the predominant genus followed by Trichostrongylus spp. in both the treated groups although very low levels of Oesophagostomum venulosum, Chabertia ovina, Nematodirus battus and Cooperia spp. were also observed occasionally. In the untreated groups Cooperia spp. was the predominant genus throughout the trial and made the major contribution to the peri-parturient rise, followed by Ostertagia spp. and Trichostrongylus spp. Oe. venulosum and C. ovina were also consistently present at low levels. Thus, the therapeutic dose of levamisole effectively reduced the worm egg counts soon after treatment in both the treated groups and prevented the post-parturient rise in the indoor, treated group with the exception of one ewe an in this group that showed/anomalous result at the end of the trial. In view of the results obtained by other workers on the efficacy of levamisole against gastrointestinal helminth parasites, it appears that some inhibited larvae, particularly Ostertagia spp. were not affected by levamisole and these larvae developed to maturity and contributed to the slight rise in egg counts observed after treatment. The post-parturient rise observed in the outdoor, treated ewes was delayed and the rise appears to be caused mainly by the acquisition of fresh infection from larvae that survived and developed on the pasture during the mild winter. An increase in the liveweight gains of the lambs from the treated groups of ewes as compared with those from the untreated ewes was observed but this was not statistically significant. However, the increase in the liveweight gains of the lambs from the two outdoor groups of ewes as compared with those from the two indoor groups of ewes was highly significant. This was probably a result of better nutrition causing a greater milk yield by the ewes kept indoor. The sudden change of environment of the indoor groups of ewes when they were moved indoors may also have acted as a stress factor.