Nematode parasites of adult dairy cattle in the Netherlands

Abomasa, blood samples and faecal samples for examination of nematode infec tions were collected from 125 dairy cows during the period November 1997-Oc tober 1998. Of these, 12 had no grazing history and were, therefore, exclud ed from this study. From the remaining 113, 88.5% had nematode eggs in the faeces. Larval identification of the positive cultures showed that Ostertag ia spp. larvae were most frequent (97%), followed by Trichostrongylus spp. (29%), Oesophagostomum spp. (23%), Cooperia punctata (20%), Cooperia oncoph ora (4%), Haemonchus contortus (2%) and Bunostomum phlebotomum (1%). The ge ometric mean EPG was 2.4. Two cows excreted larvae of Dictyocaulus viviparu s (0.1 and 0.6 LPG resp.). Worms were found in the abomasa of 108 cows (96% ). In all these abomasa Ostertagia spp. was present (100%). Trichostrongylu s axei was found in 47 abomasa (43.5%) and two cows (2%) were infected with Capillaria bovis. The geometric mean of the total abomasal worm counts was 1743 and of Ostertagia spp. alone 1615. Almost all male worms were Osterta gia ostertagi, only occasionally Skrjabinagia lyrata was found. Early fourt h larval stages (EL-4) were particularly present during the winter months: maximum in December (91.7%) and lowest in October (3.3%). Worm burdens were highest in young cows (<3 years) and older cows (>10 years). The highest i ndividual abomasal worm count was 99,800 with 86% EL-4. Eighty-six cows (76 %) had a low to moderate (100-10,000) and 22 cows (20%) a high (>10,000) to tal worm burden. Ostertagia specific antibodies were highest in late summer and autumn and l owest in spring and early summer. The same pattern, although not so pronoun ced, was observed for the serum pepsinogen values. No clear seasonal patter n was found for the Cooperia specific antibodies. Antibodies against D. viv iparus were detected in seven cows (6%). (C) 2000 Elsevier Science B.V. All rights reserved.