Iophenoxic acid as a serum marker for red deer (Cervus elaphus scoticus)

Abstract

As part of a study investigating the efficacy of toxic foliage baits for controlling red deer in New Zealand, a pen trial was conducted to determine whether red deer could be marked by oral dosing with the serum marker iophenoxic acid. The doses required to mark red deer, retention times, and the relationship between dose and serum concentration of the marker were also investigated. Three groups of three deer were fed baits containing 0.26, 2.32, and 6.10 mg iophenoxic acid per kilogram of bodyweight. Mean serum iodine concentration was significantly greater in deer fed marked baits for at least 40 days after dosing than in deer fed unmarked baits. The level of marking in each group was proportional to the dose, suggesting that iophenoxic acid may be used to quantify the amount of bait consumed by red deer. Iophenoxic acid is, therefore, an effective serum marker for red deer and could be used in short- and medium-term ecological and bait technology development field trials.