Heat stress in laying hens refers to a symptom in which the body temperature of chickens rises rapidly due to the high temperature of the living environment of the chickens, which affects the physiological functions and metabolism of laying hens.
Laying hens mainly regulate the temperature of the chicken body through the heat dissipation of the respiratory system. Generally, the temperature comfort zone of adult chickens is 21-28°C, and the relative humidity is 50-70%. If the ambient temperature of the chicken flock exceeds 28 degrees Celsius, the heat dissipation effect of the chicken body will become poor, and heat stress is very likely to occur. The effects of heat stress on flocks depend on the intensity of the heat stress.
Symptoms of heat stress:
1. Behavioral aspects: the feeding time decreases, the drinking time prolongs, panting increases, activities decrease, and wings open.
2. Physiological aspects: body acid-base imbalance, oxidative stress, respiratory alkalosis, deterioration of intestinal tight junction, and changes in cecal flora.
3. Production performance: increased dead eggs, decreased feed intake, decreased feed conversion efficiency, decreased body weight, decreased egg production rate and egg quality.
Preventive measures for heat stress:
1. Keep the chickens cool in hot weather: water curtains, sprays, sprinklers, and fans can be used to cool down.
2. Provide fresh and sufficient drinking water for chickens: cold water should be used for drinking water in summer, and the water temperature should be controlled at 15-20°C. This can effectively stimulate the appetite of laying hens, increase feed intake, and promote metabolism. Farmers should always check the water outlet of the drinking fountain to prevent the water line from being blocked.
3. The heat stress of laying hens will reduce their own body immunity, and farmers need to strengthen the prevention and management of epidemic infectious diseases. Strictly implement the immunization procedures and carry out regular antibody monitoring to avoid the occurrence of diseases in chicken flocks.
4. Nutritional regulation measures:
a. Heat stress requires higher and more efficient energy supply, and the feed needs to use fat and oil to increase the energy level of the feed.
b. During heat stress, the chicken metabolizes protein to generate heat and more nitrogen emissions, and the crude protein level needs to be appropriately reduced. And balance each amino acid level. Because lower protein levels and balanced amino acids can reduce heat stress and help flocks recover as quickly as possible.
c. Improve the electrolyte balance of the feed to 250meq/kg.
d. Increase the amount of vitamins and trace elements in the feed to maintain egg quality and eggshell strength.
e. Add additives to the feed to improve the intestinal tract, such as organic acids, probiotics, essential oils, etc.
If your laying hens need feed additives to balance nutrition and cope with heat stress, please contact Polifar.