Essential oils have a wide range of manners to provide respiratory support. The mode of action of these compounds are based on antibacterial, antiviral and anti-inflammatory effects like the breakdown of mucus in the respiratory tract and suppressing coughing while helping to widen the airways. All of these effects result in freer breathing during an infection. This article will focus on two particular effects of the essential oils peppermint and eucalyptus related to heat stress.
Warm blooded animals are homoeothermic, which means that they are able to maintain a constant body temperature by regulating metabolic heat production and heat loss. In the ‘thermo neutral zone’, animals are able to control their heat loss: body temperature is held at a constant level, feed intake is maximized and the FCR is optimal. However, when temperatures increase, especially in combination with a high humidity, animals are not able to control their body temperature, with severe impact on health and production. This principal applies to all species, however, poultry seems to be particularly sensitive to heat stress. It has been suggested that modern poultry genotypes produce more body heat, due to their greater metabolic activity. Despite this fact, most poultry production is situated in (sub)tropical areas all over the world.
The detrimental effects of heat stress on broilers and laying hens range from reduced growth and egg production to decreased meat and egg quality. Moreover, the negative impact of heat stress on poultry welfare has recently attracted increasing public awareness and concern.
Need for anti-oxidants
Physiologically, heat stress results literally in a stress response. The immune system is alarmed and affects the sympathetic nerves causing a catecholamine release, thereby leading to an increase in free radicals in the blood and tissues of the body. Free radicals attack the structure of unsaturated fat, hence damaging cell membranes. Thus, heat stress increases the need for antioxidants. Since birds do not have the ability to synthesize antioxidants in the event of heat stress and given the fact that antioxidants are reduced under oxidative stress, the addition of antioxidants to poultry diets is essential. Therefore, to cope with the adverse effects of heat stress, plant extracts like some essential oils containing antioxidants are currently being used. Peppermint and the active ingredient in eucalyptus 1,8-cineol have proven to contain antioxidant properties which support broilers during heat stress.
The use of essential oils during respiratory diseases in humans is very well-known. When suffering a cold the pleasant sensation of breathing air containing menthol and/or eucalyptus provides a cooling effect. This effect is caused by the stimulation of oral mucosa sensory cold receptors, activating the trigeminus nerve. Due to this refreshing sensation it has been shown that behavior related to heat stress, such as wing lifting and panting, is ameliorated with the addition of refreshing essential oils to drinking water or through aerosol application. This effect can be interpreted as improving animal welfare.
Immediate support during heat stress with Aeroforte
Heat stress has a major advantage over a respiratory field infection: it is predictable. The moments in which birds are exposed to an increased ambient temperature are often known in advance and immediate management actions can be implemented. Kanters has developed Aeroforte, a liquid mixture containing eucalyptus, peppermint, and menthol. It can be used both through drinking water or through nebulization. The application of essential oils is simple, effective and can improve the welfare of poultry.