Monitoring and mitigating heat stress in cattle

Abstract

Heat stress related production loss, compromised welfare and cattle mortality are global concerns which are increasing in the context of climate change. Cattle response to heat stress varies based on individuality and thermal environment. However, current cattle heat stress monitoring and mitigation is directed at the herd level, and primarily based on climatic indices that do not monitor the individual animal. The objectives of this work were to validate a sensor-based method to monitor individual cattle heat stress responses through behavioural and physiological indicators (panting score and core body temperature), and climatic indices (temperature humidity index, THI and heat load index, HLI); and to determine the ability to detect heat-susceptible animals for isolated mitigation strategy through an advanced sensor system. The feasibility of this automated monitoring system and the management of cattle heat stress was reviewed in Chapter 2 and the sensor system validated in Chapter 3. The behavioural association with different levels of panting severity (Chapter 4) and cattle heat response diversity was revealed in Chapter 5 in relation to THI/HLI and core body temperature. These results also revealed the panting duration for Individual cattle within the same group to vary significantly with diverse levels of panting being associated with the timing of resting and eating (Chapter 4 and 6). This research highlights the potential for genetic selection for heat resilience and reveals the opportunity for strategic amelioration of heat for susceptible cattle to benefit animal welfare and productivity.