Breeding for egg production techniques

1. Breeding for egg and meat
production
1.Breeding for egg production
Breeding for
Egg Production

2. Measures of Egg Production
Population: Two distinct type of population form
the basis of egg production measurement.
a) Hen-housed population: It consists of all hens
placed in the laying house at the end of the
rearing period. If a hen dies after being housed,
she is still considered a part of the population for
the purpose of measuring egg production. The
population is usually housed before the hens are
laying a significant number of eggs.

3. Measures of Egg Production
b) Survivor population: It consists only of hens
surviving to the end of test, usually after
about a year (365 days) in the laying house.
However, shorter test periods are often used.
The shorter the period, the less meaning there
is to the term survivor.

4. Measures of egg production
Egg production in flock is measured by hen-house
egg production and Hen-day egg production.
1. Hen-house egg production
i) Hen-house per bird =
𝑁𝑜 𝑜𝑓 𝑒𝑔𝑔𝑠 𝑙𝑎𝑖𝑑
𝑁𝑜 𝑜𝑓 𝑏𝑖𝑟𝑑𝑠 ℎ𝑜𝑢𝑠𝑒𝑑
in a
given period of time
ii) Hen-house percent =
𝑁𝑜 𝑜𝑓 𝑒𝑔𝑔𝑠 𝑙𝑎𝑖𝑑 ×100
𝑁𝑜 𝑜𝑓 𝑏𝑖𝑟𝑑𝑠 ℎ𝑜𝑢𝑠𝑒𝑑 ×𝑁𝑜 𝑜𝑓 𝑑𝑎𝑦𝑠
1

5. Features of Hen-house egg production
• Zero egg is valid observation
• Hens that die subsequent to placement in the
laying house and hens that never lay are part of
hen-housed population and they contribute to
the hen-house egg production.
• Hen-house egg production is a combination of 3
component parts
i) Age at first egg ii) Rate of egg production from
start of egg production iii) Viability
Any of these traits affect hen-house egg production

6. Measures of egg production
2. Hen-day egg production
i) Hen-day per bird =
𝑁𝑜 𝑜𝑓 𝑒𝑔𝑔𝑠 𝑙𝑎𝑖𝑑
𝐴𝑣𝑒𝑟𝑎𝑔𝑒 ℎ𝑒𝑛 𝑑𝑎𝑦𝑠
Average hen day =
𝑇𝑜𝑡𝑎𝑙 ℎ𝑒𝑛 𝑑𝑎𝑦𝑠
𝑁𝑜 𝑜𝑓 𝑑𝑎𝑦𝑠
ii) Hen-day percent =
𝑁𝑜 𝑜𝑓 𝑒𝑔𝑔𝑠 𝑙𝑎𝑖𝑑 ×100
𝑁𝑜 𝑜𝑓 ℎ𝑒𝑛 𝑑𝑎𝑦𝑠
2

7. Features of Hen-day egg production
• This measure of egg production is based on
survivor population which consists only of
hens surviving to the end of the test period.
• It is a measure made by the number of eggs
laid divided by the number of days a hen was
alive in the period.
• Calculation may commence i) at housing, ii) at
some other arbitrary age or iii)at the onset of
egg production of individual hen.

8. Age: Birds typically begin producing eggs in their
twentieth or twenty-first week and continue for slightly
over a year. This is the best laying period and eggs tend
to increase in size until the end of the egg production
cycle.
Body weight: In general, optimum body weight during
the laying period should be around 1.5 kg, although this
varies according to breed. Underweight as well as
overweight birds lay eggs at a lower rate. Proper
management and the correct amount of feed are
necessary in order to achieve optimum body weight.
Factors affecting Egg Production

9. Factors…
Laying House: A good house protects laying
birds from theft, predation, direct sunlight,
rain, excessive wind, heat and cold, as well as
sudden changes in temperature and excessive
dust. If the climate is hot and humid, for
example, the use of an open house
construction will enable ventilation. The inside
of the house should be arranged so that it
requires minimum labour and time to care for
the birds.

10. Factors….
Lighting schedule: Egg production is stimulated by
daylight; therefore, as the days grow longer production
increases. In open houses, found commonly in the
tropics, artificial lighting may be used to increase the
laying period. When darkness falls artificial lighting can
be introduced for two to three hours, which may
increase egg production by 20 to 30 percent. In closed
houses, where layers are not exposed to natural light,
the length of the artificial day should be increased
either in one step, or in a number of steps until the
artificial day reaches 16 to 17 hours, which will ensure
constant and maximized egg production. Effective day
length should never decrease during the laying period.

11. Factors…
Ahemeral lighting scheme: Refers to light-dark
cycles of less than or more than 24-hours. To
circumvent a limit of one egg in a 24-hour day,
the Ahemeral schemes of interest are those
of less than 24-hours.

12. Factors…..
Culling: Culling is the removal of undesirable (sick
and/or unproductive) birds, from the flock. There
are two methods of culling:
Mass culling, when the entire flock is removed and
replaced at the end of the laying cycle;
Selective culling, when the farmer removes
individual unproductive or sick birds. Culling
enables a high level of egg production to be
maintained, prevents feed waste on unproductive
birds and may avert the spreading of diseases.

13. Factors….
Feed efficiency: Feed cost amounts to >70% of
the total production cost in layers. So principal
objective in breeding for high egg production
is to increase feed conversion capability of
birds into egg. Rate of egg production is the
most important factor that determine
profitability in layers. To reduce body size of
hens keeping egg size unchanged is the
attempt of breeders to minimize maintenance
feed cost.

14. Laying curve of hens