Detailed Explanation of Technical Measures for Preventing Broiler Chick Mortality

Broiler chicks grow and develop relatively quickly and have high nutritional requirements. During the chick stage, their body temperature regulation function is not fully developed, and their resistance to disease is weak. Therefore, they must be given careful care; the slightest negligence can lead to various diseases and death. In production, preventive measures must be taken to reduce losses.

1. Strictly follow the immunization program and vaccinate in a timely manner. Chicks raised in large groups in confinement are prone to illness with the slightest inattention, especially Marek's disease, Newcastle disease, infectious bursal disease, infectious bronchitis and other diseases. Once these infectious diseases spread, they are very difficult to control and will cause devastating losses to the entire flock and even the entire farm. Therefore, in line with the principle of prevention first, active immunization must be carried out according to the immunization program. The formulation of the immunization program should vary according to the different types of pathogenic microorganisms in the farm or area. If chicks are introduced, an effective immunization program must be obtained from the supplier. If a certain infectious disease is not prevalent locally, vaccination against it should be temporarily withheld to avoid contaminating the area through vaccination. Only when the disease has occurred and been prevalent can vaccines be used for preventive vaccination.

2. Carry out timely drug prevention. Relevant statistical data show that pullorum disease is the leading cause of chick mortality, and coccidiosis is also one of the main causes of death during brooding. According to the epidemiology of these two diseases, antibacterial drugs should be added to the feed before 3 weeks of age. 0.2% oxytetracycline and 0.04% furazolidone can be added to the feed to prevent pullorum disease. After 15 days of age, coccidiosis should be prevented. Especially in environments with high rearing density and warm, humid conditions, drug prevention must be used. Drugs such as 30-60 ppm robenidine can be added to the feed. The drugs used must be weighed accurately and mixed evenly to avoid drug poisoning, and a coccidiostat drug should be replaced with a new drug after 1-2 years of use to prevent the development of drug resistance.

3. Prevent sudden changes in temperature and humidity and poor ventilation. If brooding insulation is poor and the temperature used is too low, chicks will find it difficult to maintain body temperature balance for a long time, and severe cases may freeze to death. If the indoor temperature is too high and doors and windows are occasionally opened for ventilation, colds are also likely to occur; indoor air is foul and ventilation is insufficient; temperature fluctuates and changes sharply; damp, contaminated litter and moldy feed are used; these often cause chick pneumonia; some emphasize insulation without air circulation, leading to suffocation; some use high-power light bulbs for heating, and chicks die from heat due to excessively high humidity; too high temperature and insufficient humidity can cause chick dehydration and shriveled feet and claws. All of this is due to failure to properly regulate the temperature, humidity and air in the brooding room, resulting in a poor brooding environment and bringing about stunted growth and death in chicks. Among the above factors, temperature is the most important. The temperature used during brooding should be flexibly controlled according to season, climate, type of brooder, chick constitution, age in days and other conditions. While maintaining the temperature of the brooding house, ventilation must not be ignored, but drafts and cross drafts must be avoided, and wind must be prevented from blowing directly on the chicks. Humidity has a great relationship with the growth and development of chicks. During the first 10 days, the indoor relative humidity should be maintained at 60-65%, and moisture prevention should be noted in the middle and later stages.

4. Supply complete and balanced feed to prevent nutritional diseases. A single feed variety, with certain nutritional components lacking or insufficient, can easily cause various nutritional deficiency diseases. For example, corn contains little calcium and insufficient phosphorus; long-term use of this feed can cause skeletal deformity and weakened constitution in chicks; vitamin D deficiency can easily cause poor development, soft and easily bent beak and bones, and weak or deformed legs; when selenium and vitamin E are deficient, white muscle disease occurs. Many places in China have selenium-deficient soil, and feed produced in these areas is also selenium-deficient. Therefore, attention must be paid to adding selenium compounds to the feed. If nutritional deficiency diseases are not treated, they will cause mass death. Therefore, in areas and farms where conditions permit, high-quality complete and balanced rations should be supplied according to feeding standards. If conditions are limited, multiple feeds should be mixed and fed to achieve nutritional complementation.

5. Strict disinfection to prevent umbilical infection. If the hatchery, brooding room, breeding eggs and various tools are not strictly disinfected, Escherichia coli, Staphylococcus and others can invade the yolk sac through the poorly closed umbilical opening, causing infection and inflammation and leading to omphalitis. Therefore, fumigation with formalin should be used to disinfect the hatchery, brooding room, breeding eggs and various tools. In addition, chicks with large navels should be separated individually and carefully cared for at a room temperature 2-3°C higher than the normal body temperature of chickens, and therapeutic doses of antibacterial drugs should be added to the feed to reduce the mortality rate of this disease through strengthened feeding management.

6. Provide timely "first drinking" to prevent dehydration. In chicks raised in large numbers, dehydration is caused by delayed "first drinking" due to excessively long transport time or preparations such as vaccination; or by chicks not knowing how to drink when water is provided, or by blocked drinker openings, or by too few drinkers, resulting in untimely drinking and excessive water loss in the body. Dehydration in chicks is manifested as weight loss, shriveled feet and claws, convulsions, sunken eyes, and finally exhaustion, paralysis and death. The first thing newly hatched chicks should do is drink water within 24 hours, so that they begin drinking before they feel thirsty, promoting their metabolism and preventing the phenomena of death from excessive drinking and diarrhea and death from dehydration and paralysis. Chicks transported from outside should be given a 5% glucose and 0.1% vitamin C solution within 3 hours of entering the house to strengthen their constitution, relieve stress, and promote the excretion of harmful substances from the body.

7. Prevent death from poisoning. When using drugs to treat and prevent diseases, the dosage must be calculated accurately and without error; excessive dosage will cause poisoning. When adding drugs to feed, they must be mixed evenly. A small amount of powder feed should first be mixed in, then gradually expanded to the required content according to the specified ratio. Drugs that do not dissolve in water cannot be administered through drinking water, to avoid drug precipitation at the bottom of the drinker and causing excessive intake by some chicks. Never place feed and pesticides together, which could cause pesticide poisoning; absolutely do not use moldy and spoiled feed to feed chicks; ensure indoor ventilation and beware of gas poisoning. If any of the above is neglected, it can cause irreparable losses.

8. Prevent death from piling up and crushing. Death from piling up and crushing occurs from time to time during the chick stage, mainly due to: excessive density combined with a sudden drop in room temperature; tilting and piling during transport; piling during weighing or vaccination without timely dispersal; too long a period without water and feed, especially crowding after water deprivation when feeding resumes; sudden power outages or intrusion by rodents and other factors causing fright, commotion and piling. Therefore, the rearing quantity should be determined according to the area of the chicken house, and sufficient feeders and drinkers should be provided. During the chick stage, training with 23 hours of light and 1 hour of darkness should be carried out so that they can adapt to a dark environment.

9. Strengthen management to prevent the occurrence of various vices. Severe vices mostly occur after 3 weeks of age. Common ones include vent pecking, toe pecking and feather pecking. The main preventive measure is beak trimming at 5-9 days of age. Management should be strengthened at ordinary times, rearing density should not be too high; the content of various nutrients in the compound feed should be reasonable, and inorganic salts and essential amino acids must not be lacking; light intensity should not be too strong, and the duration should not be too long.

10. Prevent animal damage. The greatest animal danger to chicks is rats, so rodent control should be carried out uniformly before brooding; doors and windows should be closed promptly when entering and leaving the brooding room, and it is best to cover doors and windows with nylon rope; block all openings in the room.

In summary, the causes of chick death are many-sided, but as long as the sense of responsibility of the keepers is strengthened, all operating procedures are strictly followed, all environmental conditions for brooding are well managed, feed with comprehensive and balanced nutrition is supplied, and strict epidemic prevention and disease control measures are implemented, it is possible to reduce the number of chick deaths, increase the survival rate of brooding, and achieve better economic benefits.