In hot environments, animals are prone to change their feeding patterns: the processes of digestion and nutrient absorption produce metabolic heat and, to control body temperature, animals limit feed consumption.

The magnitude of the reduction will depend on the species and the environmental temperature: for example, at 30ºC, Holstein cows eat 20% less; poultry 5% less; and fattening pigs consume 25 to 40% less, depending on their body weight.

40 to 60% of the productivity losses observed during heat stress are attributed to the reduction of feed intake, therefore, the practices focused on keeping a good level of feed intake are crucial. Besides management, feeding, and nutritional strategies, essential oils can be added to drinking water to increase feed intake.

The stimulatory effect of essential oils on feed intake is due to the stimulation of cold receptors located in the oral and nasal mucosa. Essential oils give the animals a very pleasant sensation of ‘freshness’, relieving heat stress instantly. In previous trials, the use of PlusBreathe©, an oral solution based on essential oils, during heat stress has been proven to increase feed intake by 5 to 17%, averaging 10.5%.

The remaining 40 to 60% productivity losses are due to metabolic imbalances, including the impairment of gut health. During heat stress, the blood flow is redirected from the internal organs to the skin surface to maintain body temperature, causing a decrease in the supply of oxygen in the digestive system, which leads to oxidative stress and leaky gut. Plant extracts are effective to maintain gut health during heat stress thanks to their antioxidant, anti-inflammatory, and microbiocide properties.