Implementation plan for forced molting of layers

Forced molting has gradually become a common breeding management measures in farms, which can deal with the problems of market fluctuation and egg quality, laying performance and decline caused by disease and so on. In actual production, the operation rules of forced molting and related to nutrition regulation directly affect the production performance of laying hens after molting.

We, Chengdu Mytech, sorted out the applicable condition, operating procedures and  standard criteria of forced molting for your reference.

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1. Concept of forced molting

Forced molting is the practice to impose strong stress on laying hens, causing unique morphological and functional changes to their body, so that flocks will stop laying eggs in a short time, and feathers will fall off and renew. Once stress stopped, flocks will recover their physique, and have laying peak again. The whole process generally takes 7 to 9 weeks.

2. Under what circumstances are forced molting taken?

2.1 The egg price fluctuates greatly: When the egg price is too low and sold out of chicken will bring serious loss, molting is a way to avoid the down market; When the egg price is too high and the breeding of new chicken may not keep up with the trend, molting to produce more eggs.

2.2 When the price of chicken is cheap and eliminating chickens does not looking pleasant, molting to extend the laying period and share total cost.

2.3 When the egg production rate and egg quality drop sharply (usually it indicates disease of the chicken, but the type of disease might be different: E. coli, causes severe peritonitis, mycoplasma synovialis disease, and avian influenza can be solved by molting; maternal vertical transmission disease, like Marek, leukemia, etc., reproductive type spreading, poor body condition chickens cannot be solved by molting.

2.4 When markets that request big eggs, such as the Northwest, Southwest of China, people likes big eggs, molting to increase egg weight by 3-5g.

3. Advantages and disadvantages of forced molting

3.1 Advantages

a. Extend the utilization time of laying hens and reduce the cost of breeding chickens

b. Improve the appearance of layers, or wait for a better price

c. Restore the laying performance of chickens without disease

d. Improve egg quality (egg shell quality)

3.2 Disadvantage

a. High rate of mortality (1.5-3%) during molting

b. The utilization time of laying hens will reduce by 3-4 months after molting

c. After molting, the weight increases, feed intake increases, eggs are large, the egg production rate decreases, and FCR increase (compared to first period)

d. 4 months after molting, the laying rate will drop rapidly (compared to first period)

4. Methods and operating procedures for forced molting

Theoretically, there are three methods, include hormone method (intramuscular injection of hormones), chemical method (high zinc, low calcium, and iodine-rich diet), and animal husbandry method (starvation method: stop water, feed, light). The animal husbandry method is the most commonly used method. The specific operation process of this method is as follows:

Preparation period→implementation period→recovery period→second laying period (from the stop of feeding, the whole cycle is 45-55 days)

5. Criteria for judging the success of forced molting

5.1 Weight changes during forced molting

Taking the group weight of fixed cage chickens as the initial weight (benchmark), it is generally considered that the best weight loss of chickens by 25-35%. The weight loss is too small to achieve the purpose of molting. Excessive weight loss of more than 35% will increase the mortality of chickens.The rate of weight recovery was positively correlated with the initial weight of chickens.

5.2 Mortality during forced molting

During the molting period, there will be always some chickens cannot resist the strong human stress and die. Therefore, the mortality rate is an important indicator to measure the success of forced molting. Under normal circumstances, when cumulative mortality of the flock reaches 1.5%, the stress should be stopped to resume feeding, so that mortality of the entire molting period can be reduced by the end of the recovery period (ie: the egg production rate reaches 50%) Control in 1～3%.

5.3 Age of reproduction after forced molting

Premature or late reproduction affects the performance of layer after molting. Generally speaking, it will take 45-55 days to regain the egg laying rate to 50% since starting forced molting, which indicates that molting can be regard as a successful process. If the egg laying rate regain to 50% within 40 days, which indicates that molting process is incomplete; if the egg laying rate fail to regain to 50% in within 60 days, which indicates the recovery of body condition is too slow, either of which will have a negative effect on the egg laying after forced molting.

5.4 Main feather molting in the process

In most cases, the body feathers start to fall off about 10 days, and amount reach to the peak in 15 to 20 days. Thus the Main feather in the wing fall off gradually and generally takes 35 to 45 days to complete the change. The success of molting depends on the change of main feather in the wing. When the egg laying rate reach to 50%, then it need to observe the main wing feather: if five main wing feathers are all replaced with new feather, the forced molting is succeed; if the main wing feather replacement is less than five, then force molting is incomplete.

5.5 Egg production rate in the new laying period

Compared with the laying rate before force molting, it will obviously increased the highest laying rate could reach to 94%. And even diseased hen could reach to  new egg production peak and maintained for at least 4 months after successfully molting. After force molting, if the egg laying rate does not improve, which indicating that the molting is failed.