The efficacy of an oxfendazole pulse release bolus system for the control of parasitic gastroenteritis and parasitic bronchitis in first-season grazing calves was evaluated in Belgium. Twenty-two calves were allocated in two groups. The calves in one group received a bolus at the time of turn out,...

A field experiment was carried out in Pennsylvania, USA, to evaluate the use of an experimental albendazole pulse release bolus (E-bolus) on gastrointestinal parasitism in calves. The bolus was administered at turnout to 9 first-season grazing calves and 9 animals were kept as controls on a...

Ten of 20 heifers aged 9-18 months were each dosed with 2 g albendazole 31, 62 and 93 days after being turned out to graze in spring, the other ten were left untreated, and grazed an adjoining strip of pasture. This treatment prevented parasitic gastroenteritis, and the treated animals had lower...

A second trial of the oxfendazole pulse-release bolus confirmed the good results against ostertagiasis of types I and II obtained previously in Belgium (Vercruysse et al. 1987). This was applied when the animals were turned out to graze in spring. Another "front-loaded" type of bolus, applied in...

An ELISA was used to detect serum pepsinogen and albumen, gastrin and antibodies against Cooperia, Ostertagia and Dictyocaulus species for diagnosis of parasitism in 7 untreated 5-8 month old calves and 7 calves treated with an oxfendazole pulse-release bolus (OPRB). During the grazing season, no...

Daily changes in serum gastrin and pepsinogen concentration were studied during 2 types of infection with O. ostertagi in calves. In a first experiment 2 calves were trickle infected (10 times 10 000 L3 Ostertagia) and 2 animals received a single infection of 100 000 L3 Ostertagia. Gastrin and...

Thirty parasite-naive Holstein-cross heifers aged 7 to 12 months were allocated into 3 groups and were treated with either an oxfendazole pulse release bolus (Repidose) administered orally at turnout or ivermectin (Ivomec) injected s.c. at 200 µg/kg at 3, 8 and 13 weeks after turnout or untreated...

Gastrin values were evaluated in 130 parasite-free calves, in 61 first season grazing calves during 6 field trials and in 8 experimentally infected adult immune cows. The gastrin values were linked to pepsinogen levels and daily weight gain. Also the influence of thiabendazole treatment on...

The influence of different levels of infection with O. ostertagi on the development of a protective immune response in calves was investigated. Four groups of calves were infected with either 5000 (Group A), 10 000 (Group B), 20 000 (Group C) or 40 000 (Group D) infective larvae (O. ostertagi L₃)...

Two farms had a low prevalence of gastro-intestinal parasites (dominated by Cooperia and Ostertagia), but there was still a difference in faecal egg counts and serum pepsinogen between 23 calves given a fenbendazole bolus at the start of grazing (at 7-8 months of age) and 23 untreated calves.