In order
to offset egg weight decrease of about 1g that we find in deep litter/free range
operations delay point of lay by one week by delaying light stimulation.
Light stimulation should not be given until birds have reached 1450 g. This will assist in ensuring good egg weight at point of lay. The aim must be a target bodyweight of 1650 g fed weight at 5 % lay. (See target body weights.)
The
feeding programme and nutritional recommendations given in this guide apply
equally to pullets reared for alternative systems.
Insoluble
grit should be offered during rearing to improve appetite and develop the gizzard.
Grit particles of 2-4 mm should be offered from 3-10 weeks of age and thereafter
3-4
mm particles should be used. Grit can be scattered on the litter or fed in
specific tube feeders at the rate of 3 g per bird / week from 3 to 10 weeks and
at 4 to 5 g a bird/week after 10 weeks. This will reduce the risk of low feed
intake at point of lay and avoid birds over consuming grit when they are
transferred to laying quarters.
In
general the principles of nutrition are the same as for birds kept in cages.
Energy
requirements are higher than for caged birds due to greater activity but the
protein
needs
are similar to those of caged birds.
Birds
are selective feeders therefore care must be taken regarding feeding techniques
and distribution.
At equal
temperatures maintenance requirements are higher by about 20 Kcal or say 7 g
of feed compared to caged birds.
Energy
requirements depend very largely on house temperature. The average house
temperature is lower than in cage systems because of the lower stocking density
within the building and the amount of time spent in the runs.
The
energy needs vary inversely with ambient temperature by 2 kcal per kg of
liveweight for each l°C. The variation is then about 3.8 kcal per bird
equivalent to 1.4 g of feed. However, towards end of lay, when birds may be
loosing feathers, extra energy requirements may be 2 or 3 times greater.
Birds
adapt feed intake well, taking into account the energy level of the food, their
maintenance requirements (bodyweight, temperature and their production rate).
Low
feed intake may be
a result of selective feed or due to the equipment and manner in which
feed is presented (see paragraph Feed distribution).
At the
start of production you should use a feed containing 2 % of oil that assists:
 |
energy
intake due to the palatable oil, |
|
early
increase of egg size. |
|
The
distribution of grit during the rearing and laying periods encourages
gizzard development and feed consumption. |
Protein
requirements are little affected by greater activity of floor birds, but are
affected by maintenance and production requirements.
The
daily requirements of amino acids are similar to those of cage birds. The
recommendations for amino acids are given in Table page 28.
When
coming into lay, the protein requirements must satisfy the needs for
maintenance, growth and production. Accordingly we must use a feed that will
cover the daily requirements for amino acids. From 2 % lay until 28 weeks feeds
specification is based on an intake level 10 g less than that seen after
28 weeks of age.
The
characteristics of feed in relation to feed consumption are set out in in the tables
here.
Protein
deficiency will result in a drop in production (percentage lay and egg size) and an increase in
food conversion ratio. In such cases, 2/3rd of the reduction of egg mass is due
to the fall in lay and 1/3rd to reduced egg size.
Reducing
egg size towards the end of lay by reducing the amino acid levels will result in a drop in production.
Calcium
levels must be adjusted according to feed intake to provide a daily calcium
intake of about 4 g at beginning of lay, 4.2 g from 28 to 50 weeks and 4.4 g
after 50 weeks. Overfeeding calcium may result in reduced feed intake.
Calcification
of the shell takes place during the night. Shell quality will depend upon
ample calcium reserves at the beginning of calcification. This can be provided
by feeding at the correct times and by using calcium in granular form.
For good
shell quality feeding times must be adjusted to meet the calcium demands of the
bird. Calcium utilisation is much greater at the end of the day and so by
feeding at that time and having the feeders empty around midday will increase
the uptake. In dark houses we can progressively introduce an artificial night
period in the middle of the day.
Calcium
carbonate should be provided in particle form, or oyster shell. Some 65 % of the
calcium should be in particle form between 2 and 4 mm to be retained in the
gizzard and ingested at the beginning of shell formation.
For
litter production, oyster shell or granular calcium can be scattered on the
scratch areas.
Deficiency
will de-mineralise the skeleton of the bird and lead eventually to bone
fractures (cage fatigue syndrome). This may be seen in flocks on slats.
The
requirements are adjusted according to feed intake and the form of presentation
of calcium carbonate. (see table pages 31 and 32).
Deficiency
in chloride can
lead to cannibalism and an excess can affect shell quality. A
In order
to improve shell quality additional sodium can be added partly as
bicarbonate of soda - especially in hot weather.
