How many times do the laying hens change their feathers before laying eggs?

3.1 Hormone levels

The level of estrogen in laying hens is relatively high, and estrogen can inhibit the growth of new hair, so the phenomenon of moulting generally does not occur before the peak of egg production. However, after the peak laying period, the level of estrogen in the body decreases, and laying hens will experience partial moulting, especially on the neck and back.

3.2 Natural hair removal

Hair loss is a physiological phenomenon involving the shedding of existing feathers, their replacement by new feather growth, and is often accompanied by a reduction in egg production or even a complete cessation of egg production.

Before natural shedding precedes adult feathers, the life process of poultry has experienced several shedding stages of alternating new and old feathers. The first molting, the down is replaced by the first new feather, occurs at about 6-8 days of age to the end of 4 weeks of age; The second moult, the first new feather is replaced by the second new feather, occurs at about 7-12 weeks of age; the third molt, which occurs between 16-18 weeks of age, is very important for production.

For laying hens, natural molting occurs every year when the daytime becomes shorter, such as around the winter solstice in my country's solar calendar (around December 20). At this time, the secretion of thyroid hormones determines the molting process, and the application of artificial light maintains a constant Under these conditions, the natural moulting of chickens is mainly achieved by regulating the "hormone clock" in the poultry.

Moulting characteristics: Males molt earlier than females. Depilation is observed first on the head and neck, then on the thorax, and finally on the tail and wings. The moult may be localized or general. The degree of shedding depends on the breed and individual bird. The duration of shedding is variable. , poor layers re-feather between 6-8 weeks of age, while good layers complete the molting process faster after a short pause (2-4 weeks).

Physiologically, egg laying stops causing more of the diet to be used for feathering (the main protein synthesized by itself), estrogen is a hormone released during egg laying that acts as a hindrance to feather formation, and egg laying stops are reduced estrogen levels. As a result, feather formation is accelerated.

3.4 Pecking addiction

Individual self-eating or mutual pecking of feathers or shed feathers, after pecking the flesh and exposing bleeding, develops flesh-pecking addiction, which is common in peak egg laying and moulting periods.

Feather pecking between flocks occurs mainly on the head, is not serious, and generally does not require treatment. Severe feather pecking is often the result of overcrowding, light problems and nutritionally unbalanced diets and can harm birds.

Injuries from feather pecking are accompanied by bleeding that attracts further cannibalistic pecking. In order to prevent cannibalism, the best way is to isolate the sick or injured chickens. The injured chickens should be treated with anti-inflammatory and bactericidal powder on the wounds, and the wounds should be painted with dark food paint or tar to reduce further exposure to other The pecking attack of chickens can also sprinkle some unpleasant powder on injured chickens.

Beak trimming or beak trimming of flocks will reduce the likelihood of feather pecking or cannibalism, especially as issues related to light, stocking density and nutrition are improved. In addition, certain breeds of flocks have also been found to be more prone to feather pecking (genetic specificity).

3.2 Season

Laying hens that start production in spring will experience partial feather loss after entering autumn.

3.3 Mating

During mating, the rooster tramples on the hen, and the hen's back feathers are torn off by the rooster's claws. In order to reduce the shedding of feathers caused by this, the rooster's claws need to be trimmed with tools such as nail scissors, and the distance on the rooster's legs can be trimmed to 1.5cm left and right length.

3.4 Production performance

When culling chickens, it is found that chickens with intact coats are often low-yielding layers. It can also be seen in the daily pathological anatomy of chickens. The laying hens with ovarian atrophy (such as infectious bronchitis during brooding, and the formation of false hens) feathers remain intact, a phenomenon that suggests that high-producing hens are more prone to feather shedding than low-producing hens. This is because low-yielding and dead-yielding laying hens have excess nutrients, and feather growth and physical development are relatively good, so the diet structure and feed intake of high-yielding laying hens should be adjusted at any time to meet their nutritional needs. Otherwise, high-yielding laying hens will not only increase the loss of coat, but also make it difficult to exert their genetic properties. For example, the Roman brown-shell hen is 72 weeks old, and the average egg production per chicken should be 19~20Kg. In actual production, chickens with more feathers fall off. The average egg production per chicken in the flock is only 15~16Kg or less.