Warrnambool Veterinary Clinic dairy heifer internal parasite monitoring project 2012 - 2013: Part 1

Summary

Traditionally, replacement dairy heifers in western Victoria have been treated for gastrointestinal parasites, or worms, either by the “calendar”, usually every 6-8 weeks, or whenever they were yarded. This habitual approach to drenching replacement dairy heifers has generally involved the application of pour-on drenches using Ivermectin as the active chemical. Recent studies in Australia and New Zealand have shown that the pour-on method of application may not deliver a consistent effective dose to each individual calf. Factors implicated in the variable dose received include animals licking their herd mates, prevailing weather conditions, long/dusty hair or animals not…