DEPARTMENT: AGRICULTURE


Factors affecting egg production
and quality

M.S.K. Mashishi 

Feed-related problems, diseases and bad management practices in intensive layer houses can result in a decreased number of eggs and also eggs which are abnormal in shape and colour.

Decreased egg production results in a smaller profit to farmers and less money in their pockets. Therefore, it is important to know how to prevent these factors affecting egg production.

FEED-RELATED PROBLEMS

Not enough drinking water

Clean and cool water must always be available to avoid heat stress. Lack of water results in reduced egg production.

No feed or decreased feed intake

Chickens tend to eat less when the feed is not tasty or when they are stressed because of environmental temperatures, especially when it gets too hot. Feed should be available at all times. 

When chickens are not well fed, egg production decreases

Low calcium in the feed

Low salt in the feed

This results in a sharp decrease in egg production. Chickens will also start pecking each other and eating feathers.

If salt deficiency is suspected, a sample of feed should be taken to the laboratory to check the level of salt. Take care when mixing your own chicken ration at home. Add the required quantity of salt, which is 0,4 %.

DISEASES

Newcastle disease (NCD)

NCD is a viral infection that can result in a mortality rate of 100 % in chickens. It also leads to a drop in egg production and quality.

Infectious bronchitis (IB)

This is a rapidly-spreading viral infection of chicken characterised by respiratory signs. It also causes drop in egg production (up to 50 %) and egg quality. Egg shells are deformed. There is a vaccine for this disease.

Epidemic tremor

This is a viral infection that results in a drop in egg production. Layers are vaccinated on the thirteenth week of age. The vaccine is given in the drinking water.

Egg drop syndrome

This is a viral infection that affects the reproductive organs of chickens. The signs are a drop in egg production, thin shells, soft shells and shell-less eggs. There is a vaccine available to prevent the disease. Layers are vaccinated on the sixteenth week of age. The vaccine is given in the muscle.

Other diseases causing a drop in egg production are salmonellosis, mycoplasmosis, infectious laryngotracheitis and internal parasites (when the chickens are kept on the ground).

MANAGEMENT PROBLEMS

Lighting

In housed chickens, lighting is important.

CHICKEN FACTORS

         Layers are usually kept for 52 weeks. After this period, they undergo a stage called moulting where they lose their feathers and stop producing eggs. Egg production will start again in the second laying period after moulting, but the eggs will be bigger, shells thinner and production lower.

CONCLUSION

When egg production and egg quality in your flock is unsatisfactory, seek help from the state or private veterinarian or animal health technician.

For further information about contact your animal health technician, state or private veterinarian
or
Animal Health for Developing Farmers
ARC-Onderstepoort Veterinary Institute,
Private Bag X05, Onderstepoort 0110

This publication is available on the web: www.nda.agric.za/publications




Information provided by
Animal Health for Developing Farmers
ARC-Onderstepoort Veterinary Institute
Private Bag X05, Onderstepoort 0110
Tel. (012) 529 9158


2001

Compiled by Directorate Communication, Department of Agriculture
in cooperation with
ARC-Onderstepoort Veterinary Institute

Printed and published by Department of Agriculture
and obtainable from Resource Centre, Directorate Communication
Private Bag X144, Pretoria 0001, South Africa