How to prevent and cure the heat stress of laying hens caused by high temperature

The high temperature in summer will seriously decrease the weight gain and egg production of laying hens, and even die. How to overcome the trouble brought by high temperature to laying hens, how to minimize the harm of high temperature to laying hens, and how to ensure the normal laying of laying hens is an important problem that chicken producers need to solve.

Laying hens

First, clinical symptoms: the feed intake of laying hens decreased, the amount of drinking water increased, feces thinned, open mouth breathing, respiratory rhythm accelerated; egg laying rate decreased, thin-shell eggs increased, protein thin. Some laying hens developed leg paralysis and could not stand up. Serious cases died, and most of the deaths occurred at night.

Second, prevention and control measures.

1 Scientific feeding and management, strict nutrition control. Before the summer heat comes every year, the nutrition level of the diet of laying hens should be adjusted in time to make the digested protein in the diet reach more than 16%. Ensure that the daily feed intake of each laying hen is not less than 110g, and the daily protein intake is about 18g. This nutrition not only meets the laying needs of laying hens, but also accumulates in the body, laying the foundation for safe summer.

After entering the summer vacation, the feed should be reformulated to ensure the daily nutrient intake of laying hens. When modifying the formula, under the condition of meeting the required amino acids, the protein level can be kept to the lowest limit as far as possible, and fat energy can also be used to replace part of the carbohydrate energy. Because layers produce heat when decomposing and digesting protein, fat and carbohydrates, fat is the lowest and protein is the most. The temperature is low in the morning and evening, feed frequently, stimulate appetite and increase the feed intake of laying hens. Reduce the feeding density. Supply cold water and increase the frequency. Ground water or spray cooling, you can also sprinkle water on the chicken head and crown, spray can add disinfectant, to achieve the dual purpose of cooling and disinfection.

(2) improve the environment of chicken house. The chicken coop and walls should be made of materials with good thermal insulation, and the roof should be painted white. Planting flowers and trees around the chicken house can effectively reduce the ambient temperature of the chicken house. A fan is installed in the house to increase ventilation and promote heat emission. The maximum continuous ventilation was used at night to lower the temperature below 20 ℃. The greater the temperature difference between day and night, the stronger the heat stress resistance of laying hens. Wet curtain can also be used to lower the temperature, which can reduce the temperature by 6 to 8 ℃.

3Drug prophylaxis. Adding water-soluble vitamins and minerals to the drinking water of laying hens can alleviate the excessive loss of minerals in laying hens caused by the increase of drinking water at high temperature. 0.3% sodium bicarbonate was added to the diet to increase the content of HCO3- in blood, increase the deposition of Ca++ in eggshell and reduce thin-shell eggs. The addition of 200mg vitamin E per kg feed can effectively regulate the levels of corticosterone and thyroid gland in laying hens, and then regulate the stability of the internal environment of laying hens. The addition of 200mg vitamin C per kilogram of diet or drinking water is helpful to alleviate heat stress.