The effect of a subclinical infestation ofNematodirusspp. upon the liveweight gain of lambs

Extract An acute disease condition in lambs associated with heavy Neinatodirus, burdens first attracted attention when outbreaks reached serious proportions in Britain in 1951. The disease was described by Kingsbury (1953) Baxter, J. T. 1957a. Vet. Rec., 69: 1007–1007. [Google Scholar] who reported the results of investigations into outbreaks in Berwickshire, Northumberland, and adjoining areas. Sincethat time, other reports from the British Isles (Stamp et al., 1955 Baxter, J. T. 1957b. Res. expt: Rec. Min. Agric. Northern Ireland, 6: 45–45. [Google Scholar]; Thomas and Stevens, 1956 Baxter, J. T. 1958. Res. expt: Rec. Min. Agric. Northern Ireland, 7: 147–147. [Google Scholar]; Baxter, 1957a Black, W. J. M., Thomas, R. J. and Greasley, J. 1958. Brit. vet. J., 114: 470–470. [Google Scholar], 1957b Brunsdon, R. V. 1961. N.Z.vet.J., 9: 16–16. [Taylor & Francis Online] , [Google Scholar], 1958 Gibson, T. E. 1958. J. comp. Path., 68: 338–338. [PubMed] , [Google Scholar]; Spedding etal, 1958 Gibson, T. E. 1959a. Brit. vet. J., 115: 120–120. [Crossref] , [Google Scholar]; Black el al., 1958 Gibson, T. E. 1959b. Agriculture, 66: 126–126. [Google Scholar]; Gibson, 1958 Kingsbury, P. A. 1953. Vet. Rec., 65: 167–167. [Google Scholar], 1959a Spedding, C. R. W., Brown, T. H. and Wilson, I. A. N. 1958. Vet: Rec., 70: 229–229. [Google Scholar], 1959b Stamp, J. T., Dunn, A. M. and Watt, J. A. A. 1955. Scot. Agric., 34: 213–213. [Google Scholar]) have added further information on the pattern of field outbreaks and clinical aspects of the disease. To date, the work on Neinatodirus infestation has been mainly concerned with the acute disease condition, epizootiology and life cycle studies, with little attention being given to the possible effects of subclinical infestations with this parasite.