Heat stress is responsible for large economic losses in the livestock industry throughout the world. Nutritional solutions can be introduced to help animals cope better to a situation of stress. Antioxidants, selenium in particular, have a key role to play.
Micro-nutrient supplements are particularly important under heat stress conditions, as they are involved in biological systems, whereby they are able to limit and/or decrease the negative consequences of oxidative stress, which are known to increase when animals experience hyperthermia. Selenium (Se) plays a key role in antioxidant nutritional solutions. Selenium imbalances in livestock can result in altered growth, reproduction and health. Selenium deficiency also results in an imbalance of redox homeostasis and ultimately in oxidative stress.
When animals suffer from heat stress, they adopt several strategies to dissipate excess heat. They increase their water consumption significantly and decrease their feed intake, thus reducing their nutrient/micronutrient uptake. Moreover they dissipate energy by increasing their heart rate, panting and by means of other metabolic adaptations. All these events have a detrimental effect on their performance, in terms of average daily gain, feed efficiency, liveability and milk production. These metabolic changes induce an overproduction of free radicals at the cellular level.
These free radicals include reactive oxygen species (ROS), which are known to seriously damage such biological molecules as lipids, protein and DNA. In order to counteract these challenges, the cell needs to be protected by means of the boosting of antioxidant activities.