Effects of breed and date of birth of lambs on gastrointestinal nematode infections
Knight, R.A.; Vegors, H.H.; Glimp, H.A.
American Journal of Veterinary Research 34(3): 323-327
1973
ISSN/ISBN: 0002-9645 PMID: 4691480 Document Number: 60388
In Nebraska, USA, a 2-year study was made of the number of nematodes naturally acquired by Suffolk, Rambouillet, Targhee, Corriedale and Navajo lambs born in winter of 1969, in early and late spring of 1969, and in early, intermediate and late spring of 1970. In the 1969 grazing season, which was characterized by above average rainfall, the lambs became heavily parasitized but significantly fewer worms were recovered from those born in winter than from those born in spring. Significant differences in worm burden were not seen between breeds. In the 1970 grazing season, the rainfall was below average and the lambs became lightly parasitized. There were no significant differences in worm burdens in the lambs born in early, intermediate and late spring but the Navajo lambs had significantly fewer Haemonchus contortus than the other breeds. In both years, the predominant parasite was H. contortus.