Prophylaxis of bovine trichostrongylidosis and dictyocaulosis in the alpine region: comparison of an early and late administration of the oxfendazole pulse release bolus to first year grazing calves.
The effect of the oxfendazole pulse release bolus (OPRB) administered at turnout, in May, or in mid-July on the development of infections with gastrointestinal nematodes and lungworms in first year grazing calves was investigated with three groups of nine animals, all grazing the same pastures in the Swiss midland region. In the calves of Group A (OPRB on 21 May) less than 20 eggs per gram of faeces (e.p.g.) and less than three Dictyocaulus larvae per 10 g (1.p.10 g) of faeces were shed for a period of 126 and 140 days respectively. Towards the end of the grazing period calves of this group excreted significantly higher levels of lungworm larvae (P < 0.05) compared with the other groups. Prior to OPRB administration on 14 July, the calves of Group B developed subclinical infections with trichostrongyles and lungworms which were similar to the untreated control Group C. By 4 weeks after bolus-administration the excretion of trichostrongylid eggs and lungworm larvae declined to levels below 20 e.p.g. and six l.p.10 g respectively. Serum pepsinogen values of the calves of Groups A and B were significantly lower (P < 0.05) compared with the control animals on days 84 and 98 after turnout and reflected mainly subclinical infections. With the exception of one Group A calf developing clinical parasitic gastroenteritis (p.g.e.) at the end of the season, clinical disease was not observed in the treated calves, while seven out of nine control animals grazing on the same pastures exhibited clinical p.g.e. with mean serum pepsinogen values exceeding 4400 mU tyrosine. Calves of Groups A and B gained significantly more weight (P < 0.01) compared with Group C (+36 kg and +41 kg respectively); differences between Groups A and B were not significant. The results indicate that in mixed grazing systems of treated and untreated calves, which are often found in the alpine region, administration of the OPRB in May or July provided good results with respect to performance of the calves. However, late administration of the OPRB has the additional advantage of coverage of the period of higher infection risk with trichostrongyles and lungworms in the late season until stabling, and should therefore be recommended.
Hertzberg
H
H
Institute of Parasitology, University of Zürich, Switzerland.
Durgiai
B
B
Schnieder
T
T
Kohler
L
L
Eckert
J
J
D000821:Animal Feed; D000818:Animals; D000969:Antinematodal Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001562:Benzimidazoles / Q000008:administration & dosage / Q000627:therapeutic use*; D002417:Cattle; D002418:Cattle Diseases; D003692:Delayed-Action Preparations; D004021:Dictyocaulus / Q000302:isolation & purification; D004022:Dictyocaulus Infections / Q000517:prevention & control*; D004334:Drug Administration Schedule; D005260:Female; D008297:Male; D009919:Orchiectomy; D006109:Poaceae; D012621:Seasons; D013557:Switzerland; D014251:Trichostrongyloidea / Q000302:isolation & purification; D014252:Trichostrongyloidiasis / Q000517:prevention & control / Q000662:veterinary*
D000969:Antinematodal Agents; D001562:Benzimidazoles; D003692:Delayed-Action Preparations; C011030:oxfendazole