Chick feeding density refers to the number of chicks per square meter of ground or cage bottom area in the brooding room. Feeding density is closely related to the growth and development of chicks. The density of chickens is too high, eating is crowded, grabbing water and food, feeling of hunger and satiety is uneven, and chicks grow slowly and irregularly; Excessive density will also cause indoor air pollution, increased carbon dioxide content, strong ammonia smell, poor sanitary environment, and chicks are prone to illness and addiction. The density of chickens is too small. Although chicks are well developed and have a high survival rate, the utilization rate of houses is reduced, which makes it difficult to keep warm, which increases the cost of chicks and is uneconomical. The feeding density of broiler breeders in the brooding stage is shown in Table 4-6.
Table 4-6 Feeding Density of Different Feeding Methods
The size of a litter depends on equipment conditions and feeding purposes. The number of each group should not be too large, the feeding effect of small groups is better, and too little is uneconomical. For example, commercial chickens can be raised in large groups, each group 1000 ~ 2000, or even 3000 ~ 5000. However, it is better to raise breeders in small groups, generally 400 ~ 500 chickens in each group, and male and female chicks are raised in groups.
(2) Ventilation in the brooding room
Although chicks are small, they grow and develop rapidly, and their metabolism is vigorous. They need a lot of oxygen and emit more carbon dioxide. The carbon dioxide emission per unit weight is more than 2 times higher than that of livestock. In addition, under the conditions of temperature and humidity in the brooding room, feces and padding are decomposed by microorganisms to produce a large number of harmful gases such as ammonia and hydrogen sulfide. Too much accumulation of these gases in the brooding house will cause air pollution and affect the growth and health of chicks. If the carbon dioxide content in the brooding house is too high, the number of breaths of chicks will increase obviously, and in severe cases, chicks will be listless, lose appetite, grow slowly and lose their physique. Excessive ammonia concentration will cause pulmonary edema and congestion in chicks, stimulate conjunctiva, cause keratitis and conjunctivitis, and induce upper respiratory diseases. Excessive hydrogen sulfide gas content will also make chicks feel uncomfortable and reduce their appetite. Therefore, it is necessary to pay attention to the ventilation of the brooding house, eliminate harmful gases in time, and keep the air in the brooding house fresh, so that the contents of harmful gases such as ammonia, hydrogen sulfide and carbon dioxide in the brooding house do not exceed 20 mg/kg, 10mg/kg and 0.3% respectively, that is, people do not feel pungent and dazzling after entering the brooding house. At the same time, we should pay attention to the change of indoor temperature to prevent the gap wind from blowing in, so as not to cause chicks to catch a cold.
There are two ways of ventilation in brooding houses: natural ventilation and forced ventilation. The ventilation of open chicken coops can be solved by natural ventilation. The specific method is: every day at noon 12, open the window of Chaoyang appropriately, from small to large, and finally it is in a half-open state. Never open the doors and windows suddenly and let the cold air blow the chicken directly. The window opening time is generally 0.5 ~ 1 hour. In order to prevent the indoor temperature from dropping, the indoor temperature should be increased by 1 ~ 2℃ before ventilation, and then decreased to the original temperature after ventilation. Closed henhouses are usually forced to ventilate by power machinery (fans). The specific requirements of ventilation are: 0.03 ~ 0.06 m3 per minute in winter and early spring, and 0. 1.2 m3 per minute in summer.