GROWTH TARGETS

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.)

FEEDING IN REARING

The feeding programme and nutritional recommendations given in this guide apply equally to pullets reared for alternative systems. (See nutritional standards.)

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.

FEEDING DURING PRODUCTION

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.

ENERGY REQUIREMENTS

MAINTENANCE NEEDS

At equal temperatures maintenance requirements are higher by about 20 Kcal or say 7 g of feed compared to caged birds.

TEMPERATURE INFLUENCE

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. (See influence of temperature on performance)

The energy needs vary inversely with ambient temperature by 2 kcal per kg of liveweight for each lC. 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.

ENERGY REGULATION

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

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.

MINERAL REQUIREMENTS

CALCIUM

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.

FEEDING TIMES

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.

PARTICLE SIZE

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.

PHOSPHORUS REQUIREMENTS

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).

SODIUM AND CHLORIDE REQUIREMENTS

Deficiency in chloride can lead to cannibalism and an excess can affect shell quality. A lack of sodium will weaken the whole organism, lead to pecking and a fall in production. Excess of either sodium or chloride will result in increased water intake.

In order to improve shell quality additional sodium can be added partly as bicarbonate of soda - especially in hot weather.