Abstract

Three mobs of mixed age Saanen milking does (n=15) were grazed separately on 3 suites of paddocks during the spring-summer lactation season between 1984 and 1985. Animals within mobs were drenched at 21 d intervals according to manufacturer's recommended dose rates with 1 of either ivermectin, oxfendazole or morantel. Ivermectin was given to all stock while not lactating. Seasonal patterns in faecal nematode egg count (FEC) were similar across all 3 groups. FEC regain measured 7 d after drenching suggested that effectiveness of the drench depended on the type used. Faecal cultures indicated that Ostertagia spp. and Trichostrongylus spp. were dominant during the summer months. Does with kids at foot were turned out for 76 d as tracers on the various suites at the end of the first trial. At slaughter, the dominant genus found was Ostertagia while appreciably fewer Trichostrongylus spp. were recovered. Significant differences in total worm burdens were detected between treatment groups. Drenching programmes appeared to have little effect on parasite control on pasture grazed solely by Saanen does. This is attributable to contamination established on pasture as well as the relative ineffectiveness of these types of drenches in this breed of goat when used at rates recommended for sheep.

JF, Smith, AG Campbell, NR Towers, NR Cow, LT McGowan, and C Wesselink

Proceedings of the New Zealand Society of Animal Production, Volume 48, , 135-138, 1988