Disease Prevention in Laying Hen in Brooding Period

 

4 major measures on how to prevent disease in laying hens during the brooding period

The brooding work plays a role in linking the past and the future in the production of laying hens. If the brooding effect is good, the laying hens will have less disease and lower mortality in future production. However, due to the lack of scientific guidance in feeding and management by farmers, various infectious diseases broke out during the brooding period, such as infectious bursal disease and mycosis. 

Here are some practical experiences for the reference of chicken farmers:

 

1. Health and epidemic prevention measures are in place

The brooding must implement "all in and all out", thoroughly disinfect before brooding, remove all feces, bedding, etc. in the brooding house, and use 2% caustic soda water to flush the ground, walls, etc., drinking fountains, feeding troughs and other utensils, with 2% -3% to Sur disinfection. 

The brooding house is closed for formalin fumigation and disinfection, and 14-15 grams of potassium permanganate and 28-30 ml of formalin are mixed for fumigation per cubic meter of space. After disinfection, it is sealed for 1-2 days for use. 

During the brooding period in the future, sanitation and epidemic prevention should also be strengthened, and the water tanks and food troughs should be disinfected regularly. The sick and dead chickens should be burned or buried in time, and should not be stacked near the brooding room.

 

In order to avoid the continuous attack of certain infectious diseases, a period of time can be arranged between each batch of chicks. 

In order to pursue high efficiency, some farmers often brood their young in batches, and there is never a break in the middle. In such chicken farms, certain infectious diseases often occur in batches, especially infectious bursal disease, Glandular type infectious bronchitis disease, causing great economic losses. 

It has been reported that many pathogenic microorganisms can survive in the external environment for a long time, 1 week or 2 to 3 months, and in the disinfection work, due to the complexity of the environment of rural brooding households, disinfection cannot kill all pathogens. 

The living area of ​​the household, and even the breeding staff may have pathogenic microorganisms left over from the previous batch of chickens. 

If the chickens are imported immediately, the pathogens will have new susceptible animals, so a certain interval is properly arranged between the brooding batches. 

Let the residual pathogenic microorganisms die naturally, which can reduce the incidence of infectious diseases and purify the chicken farm.

 

2. Carefully choose healthy chicks

First of all, carefully examine the breeder flock. Before entering the chicks, it is necessary to check the health status of the breeder flocks, the nutritional level of the breeders and the epidemic situation. 

If there have been vertically infectious infectious diseases such as pullorum and mycoplasma in the breeder farm, the incidence of these diseases in the hatched chickens will be high. 

In addition, it is necessary to carefully understand the immunization program and antibody level of the breeder flock, because the antibody level of the breeder flock not only directly affects the health of the breeder itself, but also indirectly affects the maternal antibody level of the chick and the resistance of the chick. Breeder farms enter chicks to ensure consistent maternal antibody levels.

 

Next is the selection of chicks. Healthy chicks are in good spirits, neat and clean coat color, conforming to breed characteristics, bright eyes without blemishes, flexible movements, loud calls, well-proportioned body, clean anus, feeling full in hand, struggling vigorously, belly soft, navel ring healed it is good. 

Choosing healthy and resistant chicks is a key step in brooding.

 

3. Improve the chick's own resistance

The root cause of the disease is that the body has a reduced susceptibility and resistance, so young chicks must be carefully managed and fed a comprehensive nutrient-dense compound feed. 

Each ingredient in the feed must be carefully selected, and it cannot fail to meet the nutritional standards, which will cause nutritional deficiencies in the chicks.

 

The temperature of the brooding room should be appropriate. Generally, the temperature of the first week old chicks after hatching should be 32-35°C, and then lower by 2-3°C every week until it is equal to the room temperature (20°C). 

Appropriate temperature will reduce intestinal diseases such as pullorum and Escherichia coli in chicks, and can also prevent chicks from respiratory diseases. 

While keeping warm, we should also pay attention to fresh indoor air, ventilate in time, and discharge excessive carbon dioxide, ammonia, hydrogen sulfide and other harmful gases in the chicken house in time. 

Breeders must take care of them carefully and solve problems in a timely manner.

 

4. Regular immunization and medication

In the entire laying hen production process, we must adhere to the principle of "prevention first, supplemented by treatment, and prevention is more important than cure", especially for some serious infectious diseases caused by viruses, regular immunization is particularly critical. 

The immunization program during the brooding period is generally arranged as follows: 

1. 1 day old, subcutaneous injection of Marek's disease attenuated vaccine
2. 7 day old, intranasal injection of Newcastle disease clone 30 or IV line vaccine, and injection of 0.25 ml of Newcastle disease oil emulsion inactivated vaccine at the same time.
3. 10 days 14-day-old, bursal polyvalent vaccine drinking water
4. 21-day-old, fowl pox thorn seed
5. 24-day-old, bursa-bronchus seedling drinking water
6. 30-day-old, Newcastle disease IV line or clone 30 secondary immunization
7. 35-day-old, infectious bronchitis, renal branch secondary immunization

The above immunization procedures are not fixed, and farmers can increase or decrease a certain immunization according to the local epidemic situation.

 

In immunization, the immunization of infectious bursal disease and Newcastle disease is especially strict. You must not be careless, otherwise you will have endless troubles. 

In recent years, brooding households reported that these two diseases continued to occur despite immunization. In view of this situation, when immunizing, we must determine the first immunity time. The sooner the chick is immunized, the better. Too early is easy to be affected by maternal antibodies, and too late is easy to cause disease. 

Immunization should be arranged in a timely manner; in addition, the type of vaccine should be selected. 

At present, many infectious disease pathogens have multiple serotypes and mutant strains, and the type that is popular in the region must be selected for immunization. For example, infectious bursal disease has occurred continuously. 

In the brooding farm, it is best to use the tissue-inactivated vaccine prepared from the bursa of the bursal disease of the chicken that died of infectious bursal disease for immunization, which can solve the problem of strain variation and achieve better immune effects.

 

In the process of chicken disease prevention and control, preventive medicine is an indispensable part. 

For chickens under 14 days of age, the main purpose is to prevent and control pullorum, and 0.2% dysentery can be added to the feed, or chloramphenicol, enrofloxacin, etc. 

After 15 days of age, focus on preventing coccidiosis, and you can use amprolium, diclazuril, and clodipidine alternately. 

If a serious local epidemic occurs, drug prevention should also be carried out. 

Viralin and some antiviral Ayurvedic and Chinese herbal medicines can be used for viral infectious diseases, but antibiotics must be used at the same time to prevent secondary infection.

 

First 48 hours of Broiler Brooding are Crucial

The custody, transport and brood management of chicks after birth are very important. Especially in the first 48 hours after the chicks are born, any mistakes in the management process will affect the normal development of the genetic potential of the chickens. 

In actual production, the management of these links is easily overlooked. Therefore, in order to ensure the best production performance of the flock, the chicks should be provided with the best living environment. This article focuses on issues related to ensuring chick comfort during the first 48 hours of life.

 

The central part of brooding is to provide the most comfortable environmental conditions for the chicks, and the ambient temperature around the chicks is very important to the chicks. Therefore, when brooding, we should try our best to control the temperature and air flow in the house to provide the best living environment for chicks. Incubation cannot be ignored when discussing the temperature requirements of chicks. 

Whether the chick is in the hatcher box, hatching hall, storage room, during transportation or in the brooding house, any link temperature problems will have the same effect.

 

As the entire broiler breed transitions to wider breasts, the characteristics of the chicks themselves are constantly changing. Therefore, we must understand the chicks' environmental requirements, review and evaluate our feeding and management methods, and formulate the most suitable management plan for the chicks' needs. 

Under normal circumstances, the normal rectal temperature should be between 40-40.5 degrees Celsius after the chicks are born and early brooding, and the chicks should feel comfortable in a temperature equilibrium state. When chicks are heat stressed, their rectal temperature can reach or exceed 41 degrees Celsius.

 

In actual production, the most common problem is that the chicks are heat stressed during hatching and transport, but then get cold when the chicks are brooded. Also, chicks hatched from young breeder flocks are susceptible to cold during hatching, transport, and brooding.

 

Incubation link

In addition to the management of the brooding period, the management of the hatcher is also very important for the newly hatched chicks. 

In general, hatchers are designed for maximum heat rejection of 0.11 watts/egg. However, for developing broad-breasted embryos, the latest research shows that the heat production of the embryo reaches 0.14-0.3 watts/egg, which is 27-173% different from the heat output of the machine. Therefore, when some chicks are thermally stressed due to uneven temperature in the hatcher, the utilization of yolk will be accelerated, and these chicks will die of dehydration on the farm. 

The common rectal temperature for chicks in the hatcher is between 39.4-42.2 degrees Celsius. 

Field tests show that by reducing the set temperature of the hatcher, the market weight of commercial broilers can be increased and the feed-to-meat ratio can be reduced.

 

Under normal circumstances, a day-old chick still exhibits the characteristics of a cold-blooded animal, which cannot regulate its body temperature according to the ambient temperature. Therefore, if the ambient temperature decreases, its body temperature also decreases. 

After a few days, the chicks gradually have the ability to regulate their body temperature, and can adjust their own heat production capacity according to the changes in the ambient temperature to resist the effects of temperature changes. 

However, chicks do not become fully thermoregulated until after 2 weeks of age.

 

Through on-site observation, we found that the first 48 hours were the most critical. During this stage, it is very important to maintain the chick's body temperature so that the chick's rectal temperature is between 40-40.5 degrees Celsius. 

Because the chick's gut and thyroid are still developing during this period, any stress that is too high or too low will result in a drop in performance. 

After 48 hours, low rectal temperatures in chicks are generally only seen on very poorly managed farms.

 

A research report in the Netherlands showed that some chicks were placed in the hatcher for 4 days after hatching, and the temperature was controlled to maintain the rectal temperature of the chicks between 40-40.5 degrees Celsius, and the rest of the chicks were placed on the broiler farm at a lower temperature. 

Under the conditions of brooding, the results of the first week of dead panning rates were 0.35% and 2%. Another set of experimental results showed that the chicks were raised under optimal environmental conditions for 8 days, the rectal temperature was maintained between 40-40.5 degrees Celsius, and the body weight at 8 days of age could reach 250-280 grams.

 

The transport environment of chicks

Chicks are more suitable for transportation. As long as the conditions are suitable, one-day-old broiler chicks can easily recover from the transportation process. 

A chick's yolk contains approximately 2 grams of fat and 2.5 milliliters of water. The energy contained in the fat can sustain the chicks for 3 days. 

If the ambient temperature is lower than 26 degrees Celsius, the moisture in the yolk of the chick can also be maintained for 3 days. However, if the ambient temperature reaches 40 degrees Celsius, the water in the yolk can be depleted in 8-10 hours. Therefore, if there is short-term heat stress during the transportation of chicks, even if it has no effect on the survival rate, it will affect the weight gain of the chickens. 

The results of a test show that when the chicks are subjected to heat stress at 40 degrees Celsius for 1 hour during transportation, the growth rate of the chicks at 16 days of age has a significant impact, and this effect on weight gain has persisted in the subsequent production performance. hard to make up for.

 

Through the observation of the changes in the feed intake of the chicks, it was found that the critical temperature of the primary heat stress during transportation is about 35-36 degrees Celsius. 

Exposure of chicks above the critical temperature for the first 48 hours reduces chick feed intake for the first 2 weeks and increases mortality. Therefore, the temperature around the chicks during transportation should not exceed this range, otherwise it will affect future production performance.

 

The temperature inside the box full of chicks is higher than the temperature outside the box. In general, a box of 100 chicks with a weight of 40 grams each produces 165btu/hour (174KJ/hour). 

If the air stops flowing, the temperature inside a coach full of chicks will rise by 0.6 degrees Celsius per minute, so the temperature around the chicks will exceed 40 degrees Celsius in just 10 minutes.

 

Breeder age and body temperature

In actual production, the rectal temperature of chicks also varies with the age of the breeder. Under the same environmental conditions, the rectal temperature of chicks from young flocks is sometimes only 38.3-39 degrees Celsius, while the rectal temperature of chicks from older breeder flocks is about 40 degrees Celsius. This means that chicks from young breeder flocks are susceptible to cold stress, and such flocks will not develop their genetic potential. 

This phenomenon is also demonstrated by the following experiments:

The experimental group chicks from young breeder flocks and old breeder flocks were exposed to 20 degrees Celsius for 2.5 hours, while the control group chickens were raised at 33 degrees Celsius. 

Calorie production, rectal temperature, and plasma T3 concentration (a substance involved in the body's thermoregulation) were measured in the chicks during the experiment. 

The results showed that after the chicks were treated with cold stress, the calorie production of the chicks from the young breeder flocks was significantly lower than that of the chicks from the old breeder flocks. 

The heat maintains the proper rectal temperature, however, chicks from young flocks do not have this ability. 

Furthermore, blood T3 concentrations were also lower in chicks derived from young breeder flocks after the chicks were cold-treated.

 

Reason analysis: 

1. The ability of old breeders and young breeders to transfer lipids from the mother to the eggs is different. 

2. The ability of developing embryos to utilize yolk lipids is affected by the age of the breeder flock. 

3. In addition to the age of the breeder, the hatching process also affects the utilization and absorption of fatty acids. Therefore, there is evidence that the shift in chick thermoregulatory capacity is influenced by lipids in the yolk. This may be the reason for the difference in thermoregulatory ability of day-old chicks from aged and young breeders.

 

Therefore, in actual production, we should try to avoid the premature start of breeders, especially for the current wide-breasted breeds, because the egg weight and egg yolk of premature eggs are smaller, and the lipids contained in the egg yolk are also less. 

The hatched chicks have higher environmental requirements and are prone to quality problems.

 

Brooding Temperature

The brooding temperature also has a great influence on the performance of chicks. The following experimental results are the results of the effect of low brooding temperature on flock performance:

 

The brooding temperature is 30-32 degrees Celsius, and the brooding temperature is 24-26 degrees Celsius

 

Birth weight of chicks g37.3±0.4637.2±0.49

 

12-day-old weight g248.3±2.32240.8±2.64

 

Material ratio 1.36:11.40:1

 

Feed intake g335.9±2.86336.4±2.18

 

12-day death rate %0.542.25

 

Since chicks are in contact with the litter for a long time, litter temperature during brooding is very important. The litter temperature should be at least 29°C when chicks arrive. 

In addition, the litter must also be kept dry, wet litter acts as an evaporative cooling effect. 

Through field observation, we found that the litter temperature that chicks prefer is 32-33 degrees Celsius.

 

Lower litter and brood temperatures also increase the incidence of ascites. When the chicks are cold, they will increase their metabolic function to maintain their body temperature. The increase in metabolic capacity requires a lot of oxygen consumption, which also increases the workload of the right ventricle, which in turn develops into ascites.

 

Conclusion

In order to maximize the production potential of the flock, in addition to providing the chicks with adequate feed and drinking water and a good biosafety environment, if necessary, the rectal temperature of the chicks should be detected to ensure that the chicks are in various stages of hatching, storage, transportation and brooding. The links are all under the most comfortable environmental conditions, so that the rectal temperature of the chicks is maintained between the most suitable 40-40.5 degrees Celsius as much as possible. To do this, the ambient temperature of the chicks should be maintained between 31-37 degrees Celsius after birth, preferably a slightly higher ambient temperature if the chicks are from young flocks. In conclusion, temperature management of chicks after birth is very important, especially in the first 48 hours after birth.