A survey of nematode control measures used by milking goat farmers and of anthelmintic resistance on their farms
- 1 August 1983
- journal article
- Published by Taylor & Francis in New Zealand Veterinary Journal
- Vol. 31 (8) , 139-143
- https://doi.org/10.1080/00480169.1983.34999
Abstract
Forty-seven milking goat herds, located throughout New Zealand, were surveyed for anthelmintic usage and for gastrointestinal nematodes resistant to anthelmintics. Most farmers (62%) followed a predetermined drenching programme and usually (68%) had a policy of alternating between drench families. Alternation was generally within the farming year. Kids were on average being drenched 12.5 times during their first year (range 2-34). Does aged greater than one year were all being drenched at the same frequency (average 13.4, range 2-34) irrespective of age. On each of the 47 farms, a group of goats was treated with a benzimidazole (BZ) drench (oxfendazole, OFZ, at 4.5 mg/kg on 36 farms and thiabendazole, TBZ at 66 mg/kg on 11 farms); a second group was treated with a "cell membrane depolarizing" (CMD) drench (levamisole, LEV, at 8 mg/kg on 35 farms and morantel citrate, MOR, at 10 mg/kg on 12 farms); a third group remained untreated as controls. Faecal egg counts and larval cultures were done before dosing and one week later. Faecal egg count depressions of <80% were taken as being suggestive of anthelmintic resistance. On this basis resistance was found on 79% of farms surveyed. Resistance to BZs alone occurred on 36% of farms, resistance to CMDs alone on 4% and resistance to both on 38% of farms. On 23% of farms one or other of the drenches was without any apparent effect and on one farm both of the drenches tested failed to reduce the egg counts. Post-drenching larval cultures showed Trichostrongylus, Haemonchus and Ostertagia to be the most prevalent genera remaining after drenching with BZ on 14,11, and 8 farms, respectively. After drenching with LEV Ostertagia was the dominant species on 10 farms, Trichostrongylus on 2 and on one farm the two genera were equally common. Following treatment with MOR Trichostrongylus was the dominant species on 3 farms, Haemonchus on 2 and on one farm Trichostrongylus and Ostertagia were equally common. There was a positive association between drenching frequency and the presence of resistance on farms. Possible interpretations of this association are discussed.Keywords
This publication has 7 references indexed in Scilit:
- A survey of nematode control measures used by sheep farmers and of anthelmintic resistance on their farms Part 2: South Island excluding the Nelson regionNew Zealand Veterinary Journal, 1982
- A survey of nematode control measures used by sheep farmers and of anthelmintic resistance on their farms Part 1. North Island and the Nelson region of South IslandNew Zealand Veterinary Journal, 1981
- Effect of oesophageal groove closure on the pharmacokinetic behaviour and efficacy of oxfendazole in sheepResearch in Veterinary Science, 1981
- Benzimidazole resistance in haemonchus contortusNew Zealand Veterinary Journal, 1980
- The inheritance of thiabendazole resistance in Haemonchus contortusParasitology, 1979
- The influence of breed on the susceptibility of sheep and goats to a single experimental infection with Haemonchus contortusVeterinary Record, 1978