Prevention and Treatment of Three Common Diseases in Caged Laying Hens

Cage rearing of chickens means raising chickens in cages welded from metal wire, with different types of cages designed according to chicken breed, sex and age, including chick cages, growing chicken cages, laying hen cages, breeder cages and rooster cages, etc. This can increase stocking density and save feed, among other benefits, but caged laying hens are generally susceptible to three common diseases: fatty liver syndrome, egg drop syndrome and cage layer fatigue. The conditions and their prevention and treatment methods are described below:

Fatty liver syndrome

This is relatively common in high-yielding laying hen flocks. On the surface, the laying hens appear to be in good condition, but their egg production rate gradually declines, or the egg production rate fails to reach its peak, or the peak period is shortened. In severe cases, some sick hens die suddenly. Because fatty liver in laying hens is very common and is not easily detected under normal conditions, it is easily overlooked by farmers. Necropsy reveals severe fat deposition in the liver of laying hens, with excessive fat deposited around organs such as the liver and kidneys, leading to liver hemorrhage in laying hens and causing lipid metabolism disorders. Prevention and treatment methods: 1. Increase the protein level of the feed by 1%-2%, and add a certain amount of wheat bran. For overweight chickens showing sporadic deaths in the later stage of rearing, add 500 g of Zhuangyou (bile acid powder, aminobutyric acid, xylooligosaccharide) per 1000 jin of feed, and continuous use for 15-20 days can significantly control deaths, with even better results if use is continued afterward; 2. Restrict feeding before the laying period to control the chickens' body weight.

Egg drop syndrome

This disease is more common in laying hens that produce brown-shelled eggs. When the egg production rate drops to 20%-50%, egg quality also declines, with the appearance of thin-shelled eggs, soft-shelled eggs, colorless eggs, waist-drum-shaped eggs, sand-shelled eggs, etc. The hatchability of breeder eggs declines, the stillbirth rate rises, and even if chicks hatch, their vitality is weak and the survival rate is low. Sick hens pass soft droppings and green droppings; the comb turns purplish-blue, and neurotic symptoms appear; feed intake does not decrease. Prevention and treatment methods: 1. Add Zhuangyou (bile acid powder, aminobutyric acid, xylooligosaccharide) and vitamin B12 to the diet to protect the liver and regulate the intestinal tract; to control infection, add 0.2% oxytetracycline or 0.2% furazolidone. 2. Increase the protein level of the feed and keep it at 18%-19%.

Cage layer fatigue

This is mainly caused by a deficiency of calcium, phosphorus and vitamin D in the chickens' diet, or an improper calcium-to-phosphorus ratio, as well as long-term lack of exercise, and it occurs mostly shortly after the start of laying or in the early laying period. Sick hens often lie on their sides in the cage, unable to stand, and later become paralyzed; their responses are sluggish, and many sick hens suffer fractures of the wing and leg bones, with thin and brittle bone walls. Prevention and treatment methods: 1. Add an appropriate amount of vitamin C or vitamin D in the early laying period. Keep the available phosphorus in the feed at 0.45%. For severely affected chickens, inject 50 international units of vitamin D intramuscularly to promote calcium absorption. 2. Persist in feeding compound feed. 3. Place affected chickens on the ground to raise them and let them move about freely.