Global warming has created a massive challenge for the livestock industry, especially in tropical and subtropical zones which contribute most to global livestock production. In farm animal husbandry, practices are intrinsically linked with animal health, production, and welfare. To deliver quality animal products and safe food efficiently, farmers must practice good animal husbandry and maintain their animals in peak condition. Moreover, there are nutritional solutions that enhance the resistance of animals in the period of high ambient temperature, leading to heat stress.


Heat stress : the challenge for livestock industry at peak hot seasons

Heat stress is a non-specific physiological response of the body when exposed to high ambient temperatures, which can break the balance of body redox and result in oxidative stress that affects growth performance as well as the health of animals. Heat stress (HS) occurs when the amount of heat produced by an animal surpasses the animal’s capacity to dissipate the heat to its surrounding environment. This results in an imbalance of free radicals in animal cells (Figure 1) and can affect the growth, health and reproduction of livestock. Free radicals can cause damaged cells by reacting strongly to protein molecules, DNA structures and essential fatty acids on the lipid membrane, leading to cell damage and death.

Figure 1 : Cause of heat stress on animal physiology

It may weaken the immune system of livestock, reduce the success of vaccination, and make them more susceptible to infection leading to a decline in growth performances (Figure 2). Furthermore, heat stress may affect meat color and pH, and is recognized as one of the primary influencing factors of meat quality.

Figure 2 : Consequences of heat stress on animal performance

Polyphenol as a solution to optimize livestock performance in hot seasons peak

A thorough understanding of the etiology and pathophysiology of oxidative stress in livestock will allow producers and nutritionists to design specific anti-oxidant stress solutions, in accordance with the status of each farm. Here are effective ways to reduce oxidative stress as well as prevent livestock losses:



Polyphenols have attracted much attention in recent years due to their antioxidant ability and thus, are an effective attenuator of heat stress. They exist in a variety of plants and have been used for various purposes because of their strong antioxidant ability. Plus, they promote the activation of stress-responsive proteins such as antioxidant enzymes that can inhibit reactive oxygen species (ROS).

Several researches have demonstrated the antioxidant properties of many plants and found that grape byproducts are highly concentrated in bioavailable polyphenols such as antocyanins and proanthocyanidins. Nor-Grape® by Nor-Feed is an extract from an excellent source of natural antioxidants found in selected grape. More than an antioxidant, Nor-Grape® is able to regenerate and strengthen the activity of vitamin E and vitamin C, and increase the production of endogenous enzymes like Super Oxide Dismutase (SOD) and Glutathione Peroxidase (GPx), improving the animal resistance capacity against heat stress.


Nor-Grape® optimizes the use of vitamin E

The supplementation of vitamin E is closely related to the prevention against ROS. However, in some cases, the action of vitamin E is limited by its bioavailability and the pro-oxidant effects. Moreover, the situation today shows us a price volatility of vitamin E which increase a lot. The last trials highlighted than Nor-Grape® could regenerate the effect of vitamin E and overcome its limitations. By substituting 50% of vitamin E* Nor-Grape® gives performances substantially equivalent to 100% vitamin E thanks to a synergistic effect (Figure 3). Nor-Grape® is beneficial to potentiate the activity of vitamin E especially in heat stress conditions.

Figure 3 : Synergistic effect of Nor-Grape® on the vitamin E


*1g of Nor-Grape® 80 for 11g of pure vitamin E



Human consumers are increasingly aware of the health benefits of foods rich in natural antioxidants. Therefore, the supplement of minerals, vitamin E and natural substitutes rich in polyphenols like Nor-Grape® has attracted substantial attention from livestock producers. Because the livestock industry is constantly seeking and implementing animal nutrition strategies based on the needs and wants of consumers for safe micronutrient meat products. Therefore, the supplement of polyphenol-rich natural antioxidants for animal feed help enhance animal health and performance, especially during heat stress periods.