Analysis and Discussion of the Effects of Forced Molting in Chickens

(1) Mortality rate during forced molting. Measures in a forced molting program such as fasting, water withdrawal and reduced lighting are a great stress to chickens, and flock mortality is a response that tests whether the amount of stress is appropriate. Generally, it is suitable to keep mortality during the implementation period of forced molting at no more than 3%, and by the end of the recovery period, to keep mortality within 5%.

(2) Body weight loss rate. The decline in hen body weight indirectly reflects the state of fat consumption in the oviduct. Only when the body weight loss rate reaches 25%-30% can the fat deposited in the oviduct be basically exhausted, which is crucial for improving eggshell quality in the second laying period.

(3) Rate of primary wing feather replacement. When the laying rate recovers to 50%, randomly sample 30-50 chickens; if more than half (5) of the 10 primary wing feathers have been replaced, this indicates that the forced molting was successful. Generally, during the first 7-10 days of forced molting, mainly small body feathers are replaced; from 10-20 days, primary wing feathers begin to be replaced; about 70% or more of the primary wing feathers are replaced within 50 days, and new feathers begin to grow more than 10 days after feather loss.

(4) Body weight recovery and return to laying. Generally, after resuming feeding, body weight recovers to 80%-85% of the original by 10 days, to 85%-90% by 20 days, and it is suitable for it to recover to 95%-100% by 50-60 days. Generally speaking, it is suitable for the time from the implementation period of forced molting to the recovery of the laying rate to 50% to be 50-60 days.