Key Points for Raising Laying Hens in Autumn: Environmental Regulation and Feed Management

Environmental Regulation

The growth and development of laying hens are affected by factors such as temperature, humidity, light, harmful gases, fright, noise, environmental sanitation, disinfection, mosquitoes and flies. The suitable temperature for laying hens is 18°C~25°C, with the best laying rate at 20°C. Under high-temperature heat stress, adverse reactions include pale combs, anemia, and reduced resistance; the laying rate drops by 10%~20%, the average egg weight drops by 5%~10%, and the decline in eggshell quality is reflected in an increase in thin-shelled, broken, soft-shelled, and shell-less eggs, while the mortality rate rises, and the damage to the oviduct and ovaries is irreversible. Therefore, improving the ability to withstand heat stress and preventing heat stress is the guarantee for ensuring the economic benefits of laying hens in autumn. In autumn, the temperature difference between day and night increases, and cold air invasions gradually become more frequent, causing temperature fluctuations. At this time, attention should be paid to keeping warm at night according to weather changes, to avoid the flock catching cold and developing colds and respiratory diseases. Poor ventilation in the chicken house can lead to insufficient oxygen. Because of the high temperature, the chickens drink a large amount of water, making the chicken manure very thin and prone to fermentation, producing large amounts of harmful gases such as ammonia and hydrogen sulfide, causing stress. This not only reduces the laying performance of laying hens but also easily triggers respiratory diseases in chickens. Among these, ammonia damages the cilia and inner lining of the trachea, allowing viruses and Escherichia coli to enter the respiratory system and cause respiratory diseases.

Feed Formulation

The low laying rate of hens is directly related to feed, especially the content of vitamin A, vitamin D, pantothenic acid, niacin, folic acid, choline, biotin, etc. in the feed. When the temperature is relatively high, the feed intake of laying hens is generally low. In general feed formulas, energy can meet their needs, but other components such as vitamins may be insufficient, especially fat-soluble vitamins. Due to the influence of heat stress, laying hens' requirement for vitamins increases, while vitamins in feed are affected by high temperature, with destruction intensifying and content decreasing. This is especially true for corn, whose vitamin content is generally lower than that of fresh corn, and inferior corn (such as moldy corn) mostly comes onto the market in autumn, further aggravating the harm of poor-quality raw materials. The above factors cause a deficiency of fat-soluble vitamins required by laying hens, seriously affecting their laying performance.

Chickens are naturally sensitive to mycotoxins, and even a relatively low toxin content in feed can cause massive deaths in the flock. Mycotoxins damage the body's immune system and reduce immune responses. Their effects on laying hens are mainly manifested as: decreased immunity and poor vaccine immune effects; atrophy of the ovaries and oviducts, decreased egg production, and production of deformed eggs; reduced feed intake, decreased production performance, and lower feed conversion efficiency; and reduced hatchability of breeding eggs. Different mycotoxins cause different degrees of harm to laying hens. Among the currently known mycotoxins, those with relatively large effects and toxic effects on laying hens include ergot toxin, trichothecene toxins, fumonisins, zearalenone, aflatoxin, ochratoxin, and others.

Due to the influence of heat stress, chickens have low feed intake. To ensure egg production, the energy level and nutrient concentration in the diet should be appropriately increased according to the chickens' feed intake, and the volume of the diet should be reduced, so as to compensate for the reduction in nutrient intake caused by heat stress.