Reproductive performance of northern Australia beef herds. 8. Impact of rainfall and wild dog control on percentage fetal and calf loss

Abstract

Context: Dingoes and hybrid domestic dogs (wild dogs) are lethally managed, principally by large-scale baiting programs, to protect Australia’s AU$11.4 billion beef cattle industry from predation. This strategy is promoted by pest management agencies as best practice.Aim: To investigate the impact of baiting frequency and rainfall on percentage fetal and calf loss.Methods: Using 64 property-years of data from 31 properties located across Queensland and the Northern Territory, 14 171 mating outcomes were investigated to assess whether annual rainfall, relative to 124-year mean annual rainfall, and the frequency that wild dogs were lethally controlled on each property, influenced predicted fetal and calf loss.Key results: No effect of baiting frequency on fetal and calf loss in mature cows was observed. Predicted fetal and calf loss was significantly higher in dry and very wet years than in moderate-rainfall years (P < 0.001). Losses were observed to be higher in first-lactation cows when baiting was either: not conducted, conducted every 2–5 years or several times per year (P < 0.05) when compared with baiting annually, suggesting that factors other than baiting frequency are likely to have a stronger impact on calf loss.Conclusions: Only limited empirical evidence was found to support lethal control. Further investigations may clarify whether the calves of first-lactation cows experience increased predation risk and whether the effect that dry conditions have on cow nutrition, milk supply and, consequently, the vigour of the cow and calf, may also increase predation risk.Implications: Lethal control of wild dogs to protect calves is mostly unnecessary.