Evaluating seasonal risk and the potential for windspeed reductions to reduce chill index at six locations using GrassGro

摘要: The death of newborn lambs is a major factor influencing the reproductive efficiency sheep enterprises. Adverse weather conditions (wind, precipitation and low temperature), either alone or in combination (chill index), can increase level lamb mortality to over 50% births for short periods through increased heat loss. provision shelter reduce wind speed therefore chill index (heat loss) has been shown mortality; however, reduction variable. This study used decision support tool GrassGro determine likelihood adverse occurring at six locations across south-eastern Australia which varied widely climate. Data were extracted 24 consecutive weekly between May October 39 years (1968–2006) evaluate daily precipitation, temperature, radiation, index. minimum, maximum median values calculated all climatic factors every week year combination. effectiveness reducing occurrence high was also evaluated. severity these events with rarely exceeding 1000 kJ/m2.h Temora, but both Hamilton Orange this occurred two-thirds weeks examined. Reducing by reduced number twice as many Yass compared Orange. These results show that potential will vary according location time year. In where another factor, such temperature rainfall, greater influence on index, only reduces speed, be less effective than driver