Scientific prevention and treatment methods for low-temperature disease in chickens raised in autumn and winter

During their growth and development in autumn and winter, chickens are highly susceptible to osteomalacia and rickets. Because these conditions are often caused by low temperatures, they are also called “low-temperature disease”. This is a nutritional disease that occurs when the metabolism of calcium, phosphorus and other substances in chickens is disrupted during low-temperature seasons, causing abnormal growth of bone tissue. In adult chickens, the disease is usually called osteomalacia, while in chicks it is usually called rickets. Whether in adult chickens or laying hens, normal growth is greatly affected after onset, especially in laying hens, where egg production drops sharply, eggs become smaller and quality deteriorates. Therefore, during low-temperature seasons in autumn and winter, chicken farmers should pay attention to the prevention and treatment of “low-temperature disease”.

Symptoms: Affected chickens mainly show poor development, poor appetite and ruffled feathers, with soft and bent bones, bead-like hard nodules at the junction of the soft ribs and hard ribs, and a flat and flattened chest that protrudes to both sides. In severe cases, the beak becomes as soft as rubber and can bend, making pecking difficult; adult chickens have pain in both legs and cannot stand, with most lying down. Chicks have both shanks bent in an arc or X shape, a curved spine and weak crowing.

Prevention: (1) The diet should be formulated according to chicken nutritional standards, with sufficient calcium, phosphorus and vitamin D provided. Where conditions permit, a complete compound feed is best to ensure the chickens' calcium and phosphorus needs. (2) The chicken farm should provide sufficient sunlight exposure (sunlight passing through ordinary glass is ineffective). Generally, 16 hours of sunlight per day is appropriate. Where sunlight is insufficient, electric lighting can be used instead. Where conditions permit, it is best to let the chickens sunbathe on sand; enclosed chicken farms should increase fluorescent lighting, preferably by 10 minutes per week, and keep it constant. At the same time, supplement with grit to improve the chickens' feed digestibility. (3) Supplement an appropriate amount of green feed or silage, and feed rich in vitamins (especially vitamin D), such as green leafy vegetables, carrots, black locust leaves, etc.

Treatment: (1) When diseased chickens are found, promptly adjust the ratio of calcium and phosphorus in the diet. In general, the calcium and phosphorus content in the diet is: chicks 0.9%, growing chickens 1.1%, laying hens 3.1%-3.5%, and broilers about 0.9%. Among these, the calcium-to-phosphorus ratio is preferably: chicks 21:1, growing chickens 23:1, and laying-period chickens 7:1. At the same time, additives can be added to increase the content of various minerals and vitamins in the diet. In particular, attention should be paid to supplementing vitamin D or cod liver oil to promote the chickens' absorption of calcium and phosphorus. In general, add 2000 international units of vitamin D per kilogram of feed, and 1-2 milliliters of cod liver oil per chicken per day. (2) Add substances rich in calcium and phosphorus, such as bone meal, shell meal or eggshell meal, and stone meal, to the diet. In general, bone meal accounts for only 1%-2% of the diet; stone meal and shell meal together account for 1%-2% in chick feed, and about 2% in the diets of laying hens and breeding chickens. (3) In severe cases, diseased chickens can be given subcutaneous injections of vitamin D injection. Use 6000-10000 international units per kilogram of body weight per diseased chicken per day, repeated once every 3-5 days. Generally, 2-3 times is enough to see results, and the effect is better if combined with oral calcium supplements.