Project aims to determine heat stress limit for sheep in New Zealand

AgResearch scientists are developing a tool to help sheep farmers better predict when their animals are likely to be heat-stressed. The tool, called a heat load index, will be used to help farmers proactively manage this risk for their animals. The project, funded by the Ministry for Primary Industries, has scientists monitoring a small mob of Romney ewes in a paddock at its Ruakura site, where the data collected will be used to formulate the index. The research was outlined at a field day at Ruakura organised by the MPI. AgResearch scientist Karin Schutz said they are monitoring the ewes’ movements and time spent in shade and grazing pasture. The sheep’s respiration rates are also recorded and counted. The index – along with a temperature threshold to advise when farmers should start mitigating for heat – should be ready by next summer. A heat stress risk map will be created using NIWA weather data and sheep population density to show areas where heat stress is potentially an ...