In Egypt, ambient temperature can remain consistently high for extended periods of time and sudden recurrent hot and humid waves that have more harmful effects. So poultry production suffers significant losses every year because of heat stress, leading to economic losses to the poultry farmers. During these periods temperatures approached 40˚C most of the time and humidity reaches 75%. A temperature above 30˚C represents a heat-stressed condition for birds and is one of the most common stressors that affect poultry production criteria where the ideal temperature for broilers is 10-22˚C to get optimum body weight and 15- 27˚C for feed efficiency.
Heat stress is principally important in intensive poultry operations especially in broilers lines because their higher production performance and feed conversion efficiency make today's chickens more susceptible to heat stress than ever before.
High mortality, decreased feed intake, lower body weight gain and poor feed efficiency are common adverse effects of heat stress often seen in meat-type poultry flocks. In addition, heat stress increases lipid oxidation as a consequence of increased free radical generation, a condition that enhances the formation of reactive oxygen species (ROS) and induces oxidative stress in cells. Antioxidant enzymes catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) play a vital role in protecting cells from the harmful effects of ROS. Synthesizing these enzymes is an important regulation, in terms of animal response to stress conditions. However, this response will be effective only if cofactors such as Se for GPx and copper, zinc, and manganese for SOD are available.
Heat stress is divided into acute heat stress and chronic heat stress with the participation of different antioxidant enzymes. Under acute heat stress, ROS level in the body is rapidly increased and the antioxidant enzyme system also responds rapidly, by which the activity of CAT, SOD, and GSH-Px is increased significantly to remove excessive free radicals. Chronic heat stress can break the antioxidant enzyme system and cause ROS accumulation in the body to induce oxidative stress by decreasing the activity of CAT, SOD, and GSH-Px.
Article Polyphenols as Potential Attenuators of Heat Stress in Poult...
Article Effects of acute heat stress at different ambient temperatur...
Heat stress can increase the expression of Hsp70, which can reduce ROS production by increasing the activity of antioxidant enzymes such as superoxide dismutase (SOD) [
Poor performance of the birds under heat stress may be due to lower synthesis and increased degradation of proteins.
Sir, generally, heat stress nor cold stress affects the metabolic reactions of enzymes. Therefore, supplementation such as Vitamin B complex or Vitamin E may help to compensate for the loss of these important elements out of stress.
If you mean the antioxidants in the feed and expose them to high environmental temperatures, this will have a positive effect, as the temperatures work to destroy these enzymes added to the feed, so the addition is close to the date of giving the feed or preparing special stores that are not exposed to high temperatures and humidity
- Badges
- Science topic
- Similar topics
- Medicine
- Disease
- Infectious Diseases
- Immunization
- Vaccination
- Vaccines