Influence of acute mild winter conditions on the productivity of feedlot cattle: An Australian perspective

The impact of cold stress on feedlot cattle has received limited investigation in temperate climates. However, cold stress has been found to impact cattle welfare and production in temperate climatic conditions, where ambient temperature (T_A), precipitation, relative humidity (RH), wind speed (WS) and solar radiation (SR) all influencing apparent temperature. While there are many indices to quantify cold stress in cattle, there are limited indices that directly relate to cattle and account for all the interactions between climatic variables. This makes cold stress difficult to quantify, with on-cattle measures such as core body temperature and shivering difficult metrics to obtain in feedlot cattle. Moreover, individual cattle will react differently to cold conditions based on their production, age, sex, coat characteristics (colour and type), breed and nutrition. While cold stress can be difficult to measure, the production status, behavioural and physiological effects of cold stress have been identified, but generally under what could be considered as extreme cold stress events. Similarly, while mitigation strategies such as shelter, bedding and windbreaks have been investigated, limited information is available surrounding their usefulness in temperate climates. Further research is needed to fully investigate the effects of cold stress and how to mitigate those effects in feedlot cattle under conditions, such as those found in Australia.