Management of Layers during Molting

Management of Layers during Molting

Dr. Ankit Sharma^1*, Dr. Anil Kumar²

¹PhD Scholar (Poultry Science), Department of Livestock Production Management, College of Veterinary and Animal Sciences, GBPUAT, Pantnagar

²Professor, Department of Livestock Production Management, College of Veterinary and Animal Sciences, GBPUAT, Pantnagar

*Corresponding author email: ankit291994@gmail.com

Introduction:

Molting or moulting is the process of shedding and renewing feathers. During the moulting, bird takes complete rest from laying and the increase its body reserves of nutrients. The provision of new feathers or coat is a natural process, to maintain the birds’ ability to escape enemies by flight and to provide protection against cold winter conditions. Under natural conditions, moulting in adult birds will occur once a year, however it may occur in certain individuals twice in one year and more rarely only once in a period of two years.

During molting, the metabolic rate and protein synthesis increases, along with a loss of adipose tissue, bone mass and humoral immune system suppression (Kuenzel, 2003; Mumma et al., 2006). Molting also results in an alteration of the hormonal system of the hen (Swanson and Bell, 1974 a,b,c,d; Davis et al., 2000). Hormonal changes are typically related with molting and broodiness in the wild, seasonal changes resulting in limited food supply and the husbandry practice of molting in the commercial egg and breeder industries. The hen is capable of coping with changing conditions in its environment to maintain physiological homeostasis (Clarenburg, 1986; Freeman, 1987). From growth to point of lay, the chick goes through one complete and three partial moults. After which the mature bird normally undergoes one complete moult a year, usually in autumn although this depends on the time of the year at which the bird commenced laying. Generally complete moulting occurs from 1-6 weeks and partial moulting at 7-9 weeks, 12-16 weeks and 20-22 weeks and during this latter moult the stiff tail feathers are grown.

Natural moulting usually begins during March-April and should be completed by July when egg production start again. The three main factors which bring about moulting are:

• Physical exhaustion and fatigue.
• Completion of the laying cycle. Birds lay eggs only for a certain period of time.
• Reduction of day length resulting in reduced feeding time and following loss of body weight.

Eleven months continuous production is expected from pullets hatched in season, so that if a flock of pullets commenced laying in March at six months of age, they should continue laying until the following February, although the odd bird may moult after laying for a few weeks. However, these few bird should begin producing eggs again after June 22 (the shortest day of the year) and continue in production until the following autumn.

Forced molting:

Forced molting is also known as induced molting, is the practice by poultry industry of artificially inducing a flock to molt by withdrawing food for 7–14 days and sometimes also withdrawing water for an extended period. Forced molting is usually implemented when egg-production is naturally decreasing toward the end of the first egg-laying phase. During the forced molting, the birds stop laying eggs for at least two weeks, which allows its reproductive tracts to regress and rejuvenate. After the molt, egg production rate usually peaks slightly lower than the previous peak, but egg quality is improved. The purpose of forced molting is therefore to increase egg production, egg quality and profitability of flocks in their second or subsequent laying phases, by not allowing the hen’s body the necessary time to rejuvenate during the natural cycle of feather replenishment. Domestic chickens have been bred for high egg production and under ordinary circumstances they do not go through a complete molt until the end of a long and intensive laying period. It is possible however, to speed up the process through a program of forcing pullets to molt rapidly. The ability of a hen to produce eggs well after the molt can be attributed only to the rest period the bird receives.

The thumb rule for molting is to reduce body weight to mature body weight i.e. about 1250gms. Another way is to reduce the weight by 25 % of the weight at the time of molting. The older birds are generally 1650gms after 60 weeks of age. Reduction of body weight from 1650 to 1250gms is less stressful and results in less mortality. The type of molting desired depends on the situation:

• Fast molting: Flock to come back into production fast. There is water restriction also. It takes 6 weeks from start to 50% production.
• Normal molting: It takes about 8 weeks. Flock is off feed till the flock looses 30% weight and start feeding grower ration. Flock should be vaccinated and given layer feed as soon as the production starts. If the initial weight of the flock is low, the flock may loose the weight faster and there can be mortality. Low density ration should be fed for two weeks to avoid mortality.
• Slower molting: If the flock looses enough body weight and farmer still do not need production, feed the flock with low quality ration like 10% protein and may be only 60gms per day to delay the production. This might take 10 weeks.

Birds above 60 weeks are ideal for molting are because the production of older flocks is low. Also older birds are heavier and take longer time to loose weight i.e. more feed saving.

Types of Molting:

Egg producing hens may be molted one or more times, the two general types of programs are:

Two-Cycle Molting Program:

It includes one molt and two cycles of egg production. The hens are force molted after about 10 to 12 months of egg production, brought back into about 6 months of egg production, then sold.

Three-cycle molting program:

It includes two molt and three cycles of egg production. The hens are first molted after about 9 months of production. Then held through another shorter production period, molted again, followed by an even shorter period of lay, then sold. This periodic molting program totals about 24 month: longer programs are seldom profitable.

Precaution Taken:

1. Vigorous culling of unhealthy, unthrifty and underweight birds should be carried out before the starting of this program.
2. Only good first year flock should be molted.
3. During hot climates, do not follow the water restriction program.
4. Check the flocks for diseases and vaccinate them against pox, IB and ND.
5. The maximum mortality should not exceed 2%.
6. Body weight of the flock should be reduced to 23%.

Programs for two cycle molting:

The three basic programs are:

1. Conventional Force Molting program (on again, off-again program)
2. Washington Force Molting Program(Low feed intake)
3. California Force Molting Program(No water Restriction)
4. Chemical Molting program (By feeding of chemicals like Zinc, Low sodium diet etc)

Procedure for forced molting:

• Grade the birds and cull the weak and lame birds.
• One week prior to this program deworm the flock.
• Four days after deworming vaccinate the flock against ND and IB.
• Give three days 24 hrs light before the start.
• Weigh the selected birds on day 1 morning (About 50)

• On day 10, check bird for the body weight reduction. If it is not reduced to a desired level continue the fasting.
• After 7 days, if the mortality is increased abnormally start feeding the birds with grower mash or cracked grains at the rate of 30g/bird and continue till the body weight is reduced to a desirable level.
• A day before starting of the feeding, give jaggary water @1kg/1000 birds and give electrolytes as well so that the systems get activated.

Advantages:

• Cheaper to carry a bird through a moult than to buy replacement pullets, fewer replacement pullets may be needed. So, it can save money, time and transport.
• Moulted birds are hardier and not as prone to disease. If strict culling is carried out during the first year, only high producing efficient birds will be retained.
• When the rate of lay of the pullets declines in the summer, the additional eggs from the moulted birds should sustain an adequate supply. The following autumn the older birds can be killed for the table, the best pullets allowed to moult and another lot of pullets on point-of-lay purchased.At the same time a relatively constant year round supply of eggs is guaranteed.

Disadvantages:

• Although moulted birds eat less feed than pullets, they also lay less egg. Overall, their conversion of feed into eggs, and feed cost per dozen eggs is higher.
• During the moult the birds continue to eat but remain unproductive.
• If the birds are to be slaughtered for the table after two years of laying they will not be as tender to eat too few birds may be retained to provide sufficient eggs the following year.

Conclusion:

Moulting is the process of shedding and renewing feathers. Bird takes complete rest from producing eggs and the increase its body reserves of nutrients. It is a natural process, to maintain the birds’ ability to escape enemies by flight and to provide protection against cold winter conditions. Birds above 60 weeks are ideal for molting are because the production of older flocks is low, older birds are heavier and take longer time to loose weight i.e. more feed saving. Forced molting is artificially inducing a flock to molt by withdrawing food for 7–14 days and sometimes also withdrawing water for an extended period. The purpose of forced molting is to increase egg production, egg quality and profitability of flocks in their second or subsequent laying phases, by not allowing the hen’s body the necessary time to rejuvenate during the natural cycle of feather replenishment. It is cheaper to carry a bird through a moult than to buy replacement pullets, so it can save money, time and transport. Moulted birds are hardier and not as prone to disease. The additional eggs from the moulted birds should sustain an adequate supply during summer when there is less production. Although moulted birds eat less feed than pullets, they also lay less egg. Overall, their conversion of feed into eggs, and feed cost per dozen eggs is higher. During the moult the birds continue to eat but remain unproductive.

NON-FASTING MOLT RECOMMENDATIONS

FORCED MOULTING IN POULTRY

FORCED MOULTING IN POULTRY

NON-FASTING MOLT RECOMMENDATIONS

References:

W.J. Kuenzel. 20Introduction. Univ. California Coop. Ext. Bull. AXT-410.

Swanson, M. H., and D. D. Bell. 1974b. F03. Neurobiology of molt in avian species. Poult. Sci., 82: 981-991.

J.O. Mumma, J.P. Thaxton, Y. Vizzier-Thaxton, W.L. Dodson. 2006. Physiological stress in laying hens. Poult. Sci., 85: 761-769.

Swanson, M. H., and D. D. Bell. 1974a. Force molting of chickens. 1.

orce molting of chickens. 2. Methods. Univ. California Coop. Ext. Bull. AXT-411.

Swanson, M. H., and D. D. Bell. 1974c. Force molting of chickens. 3. Performance characteristics. Univ. California Coop. Ext. Bull. AXT-412.

Swanson, M. H., and D. D. Bell. 1974d. Force molting of chickens. 2. Egg quality. Univ. California Coop. Ext. Bull. AXT-413.

G.S. Davis, K.E. Anderson, A.S. Carrol. 2000. The effects of long term caging and molt of Single Comb White Leghorn hens on heterophil to lymphocyte ratios, corticosterone and thyroid hormones. Poult. Sci., 79: 514-518.

1986. Clarenburg. 1986. Syllabus for the Course of Veterinary Physiology I (11 ed.), Dept. Anat. Physiol., Coll. Vet. Med., Kansas State Univ., Manhattan.

B.M. Freeman. 1987. The stress syndrome. World’s Poult. Sci. J., 43: 15-19.

GOOD MOLTING PRACTICES IN COMMERCIAL LAYERS

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