Impact of Heat Stress on Livestock and Mitigation Strategies to Improve Productivity and Well-Being

Extreme heat events may induce sub-optimal livestock performance and the negative impact of heat stress (HS) on animal productivity is often a symptom of a larger welfare issue. Poor welfare will occur when an individual has difficulty adapting to a stressor resulting in a greater strain response. This response may vary depending on previous HS exposure, genetics, species, or production stage and the physiological changes that occur to ensure survival may impede the efficient conversion of feed energy into animal products. The impact of HS on livestock productivity is well-documented and ranges from decreased feed intake, body weight gain, and reproductive efficiency to altered carcass composition and meat quality. As a result, decreased animal performance may cause profit losses for producers and can affect the economic sustainability of all livestock industries. Furthermore, food security may be threatened in regions that experience year round HS. Given the negative impacts of HS on livestock, appropriate mitigation strategies must be implemented to maintain productivity during times of high thermal heat loads and promote recovery after HS has occurred. Strategies to mitigate the effects of HS may vary depending on region, resources (economic and natural), and species. They can include management strategies (i.e., use of cooling technologies, etc.), genetic improvements, and nutritional additives. Mitigating the negative effects of HS is key to improving productivity, preserving proper animal welfare standards, and reducing the stress load incurred by livestock species.