| occurrence and seasonal behavior of gastrointestinal nematodes infecting maine dairy cattle. | gastrointestinal tracts of 48 yearling maine dairy cattle were examined (8 animals every 2 months) for 1 year. adult and immature nematodes were identified and counted. species recovered were bunostomum phlebotomum, cooperia mcmasteri, cooperia oncophora, cooperia pectinata, cooperia punctata, haemonchus placei, nematodirus helvetianus, oesophagostomum radiatum, ostertagia circumcincta, ostertagia lyrata, ostertagia ostertagi, trichostongylus axei, and trichuris ovis. strongyle parasitism was ob ... | 1977 | 145192 |
| persistence on pasture of the infective larvae of nematodes parasitizing maine dairy cattle. | yearling calves infected with ostertagia ostertagi, cooperia oncophora, and nematodirus helvetianus were allowed to graze on a 0.8 ha pasture plot contaminated during june and august 1977. in june 1978, the plot was subdivided into 10 subplots of equal size. grazing in 5 of these plots was allowed, each for 1 month, during june, july, august, september, and october by groups of 2 parasite-free 16-week-old calves. the procedure was repeated in 1979 with the remaining 5 subplots. each group of cal ... | 1980 | 7224300 |