Abstract

There are no data on the potential for 1080 used for pest control to cause delayed deaths or impaired productivity in livestock following multiple, sub-lethal doses. Recent losses of late-gestation ewes exposed to weathered 1080 baits has also led to speculation that pregnant ewes may be unusually sensitive to the toxin. To address these data gaps, groups of 20 Perendale ewes, non-pregnant or pregnant with twins, were administered either a single (0.25 mg/kg) or multiple oral doses (0.05 mg/kg over 3 consecutive days) of a 1080 cereal pellet. The highest mortality occurred in the single dose groups (pregnant 45%, non-pregnant 21%) compared to the multiple dose groups (pregnant 35%, non-pregnant 0%). There was no mortality in the control group of pregnant ewes. Log-linear modelling showed highly significant treatment effects (P = 0.0003) and differences (P = 0.045) in acute mortality rates between pregnant (40%) and non-pregnant ewes (10%), which was linked to increased bioavailablity. There were no differences in the incidence of metabolic diseases, lambing percentages, lamb survival, or growth rates between dosed and undosed pregnant ewes. This study demonstrated that extra care should be taken to avoid exposure of pregnant ewes to even small bait fragments, but also provides further evidence that there are no long-term health effects in animals that survive accidental 1080 poisoning.

CE, O'Connor, LM Milne, DG Arthur, WA Ruscoe, and M Wickstrom

Proceedings of the New Zealand Society of Animal Production, Volume 59, , 250-253, 1999