In a feedlot environment, acclimatisation means that the animal has adjusted to the high-energy food and also the higher humidity and local climatic conditions.
An animal that is NOT acclimatised will have a HIGHER risk of a heat event, so it is important to understand what acclimatisation means.
Animals will reduce their risk if they are introduced to the feedlot rations before entering the feedlot. This acclimatises the animals to the higher internal heat load generated by the high-energy diet. Animals will start to acclimatise within 7 days but it takes 20-30 days to be fully acclimatised to the weather conditions. This means that during a rapid change in local weather conditions (such as a heat wave), animals that have not experienced these types of conditions recently will be more susceptible to heat stress.