Detailed Explanation of Key Points in Artificial Forced Molting Technology for Chickens

1. Chemical method: After chickens ingest an excessive or insufficient amount of chemical substances within a certain period, their metabolism is disturbed and the functions of internal organs are disordered, resulting in the hens stopping laying or molting. After the chemical agent is removed, the hens rest and their physique recovers, and under the condition of being fed normal feed, they again recover a second laying period. At present, the most commonly used chemical method is feeding a high-zinc diet. For example, when feed containing 2% zinc is fed in the diet, after 3 days the laying rate of the chickens drops below 50%, and after 6 to 7 days laying stops completely; after removing zinc, within 2 weeks the laying rate of the hens can exceed the level before zinc feeding. Alternatively, add 2.5% zinc oxide to a compound feed containing 3.5% to 4% calcium, let the chickens feed freely, and do not restrict water supply. Generally, by the 4th day the feed intake of the hens drops by 75% to 80%, and by the 7th day the laying rate almost drops to 2% to 0%. After stopping this feed for 25 to 30 days, the laying rate of the hens can reach 50%.

2. Hormone method: When using this method, the chickens feed and drink freely, and for the first 12 days the light is shortened to 8 hours. For example, after intramuscular injection of 30 mg progesterone into hens, the primary wing feathers and secondary wing feathers are replaced very quickly, and laying begins 41 to 48 days after molting. The laying performance of hens treated by this method is slightly poorer. Because injecting hormones easily disrupts the hormone balance in the body and causes metabolic disorder, the hormone method is rarely used.

3. Animal husbandry method: Through water deprivation, feed deprivation, and light deprivation, stress factors are artificially imposed on chickens, disrupting the normal routine of the chickens and causing sudden physiological pressure on them; hormone secretion loses balance, lutein decreases, and this in turn reduces estrogen in the ovaries, resulting in follicular atrophy and causing cessation of laying and molting. In practice, the animal husbandry forced molting method of water deprivation, feed deprivation, and light deprivation has many varied schemes, all of which can achieve certain results. (1) Rapid forced molting method: The goal is to restore the hens to a 50% laying rate within 6 weeks. The method is as follows: 1) Deprive of feed for 10 days; 2) At the beginning, stop supplementary lighting in open-sided chicken houses, and shorten lighting to 8 hours in enclosed chicken houses; 3) Provide free drinking water; 4) Feed shell powder during the molting period; 5) After 10 days of feed deprivation, allow free access to laying hen feed and restore the lighting used before molting. (2) Common forced molting method: The goal is to bring the hens to a 50% laying rate within 6 to 8 weeks. The implementation method is as follows: 1) Deprive of feed for 10 days; 2) Provide free drinking water; 3) Stop supplementary lighting in open-sided chicken houses, and shorten lighting to 8 hours in enclosed chicken houses; 4) From the 11th day, continuously feed cracked pellets for more than 4 weeks; 5) When laying resumes, begin feeding laying hen feed and restore the original lighting.

4. Combined method: This method is an improved forced molting method adopted by combining the advantages of the animal husbandry method and the chemical method. The method is as follows: deprive of water and feed for 2.5 days, stop artificial supplementary lighting, then begin supplying water; from the 3rd day, let the chickens feed freely on feed containing 2% zinc powder or 2.5% zinc sulfate for 7 consecutive days. Generally, after 10 days all laying stops, and at this point normal lighting is restored. After molting begins, the hens lay eggs again 20 days later. Fifty days after molting begins, the hens reach a 50% laying rate. With the combined method, the mortality rate of hens during the molting period generally does not exceed 1%.