Intensive / Nutrition and Feed Management
Nutrition and Feed Management
Feed Presentation
A consistent quality feed is essential. Sudden changes in appearance and raw material make-up must be avoided. Grist profiling of good textured mashes, readily accepted by laying birds, suggests that the major portion of the particles (70 - 80%) should fall within the range 1 mm to 3 mm. The remaining particles should be evenly dispersed above and below this range.
To minimise the levels of small dusty particles, granular forms of the major minerals such as limestone, the phosphates and salt should be used.
The inclusion of a vegetable oil in the formulation will also help dampen and contain the smaller particles within the meal and encourage feed intake. Oils, which have the lowest heat increment during digestion, are also the most cost-effective source of energy. Care however should be taken that the oil is stabilised to prevent oxidation and rancidity.
To increase feed intake during the first few weeks of life (0 - 3 weeks) good quality crumbs, free from dust, as opposed to mash, can be used to good effect. Thereafter to encourage the development of an active and healthy digestive tract, the feeding of a coarse mash is recommended.
Protein
The dietary specifications that are detailed will provide the required daily nutrients at each stage of the growing and laying cycle, the latter being based on the assumed daily feed intake.
The levels of the essential amino acids Lysine, Methionine and Cystine, Threonine and Tryptophan are designed to support the egg production and egg mass detailed in the guide’s performance tables.
Protein levels have been kept to a minimum to reduce the excessive intake and the subsequent and energy-dependant excretion of non-protein nitrogen. Amino acid levels should be achieved using the more digestible synthetic sources.
Major Minerals
Calcification of the shell takes place during the night photoperiod when the birds are not actively eating feed. The source of calcium during this period becomes residual feed in the digestive tract and the labile medullary bone reserve.
Small particles of limestone are not retained in the gizzard and are readily excreted leading to poor shell quality. It is recommended that granular limestone forms a major portion of the source so that there is retention in the gizzard for utilisation during shell deposition.
Oyster or marine shell with larger particles can also be introduced, especially during the afternoon, as a supplementary source of calcium, which the bird can self-select.
Phosphorus levels have been increased in all feeds throughout growing and lay. Phosphorus has been shown to be a critical nutrient in the development of ovum and the maintenance of bone quality in lay. Levels later in the laying cycle are reduced, as too much phosphorus can be detrimental to shell quality.
Electrolyte Balance
A correct balance of the electrolytes sodium, potassium and chloride is essential. An excess of any of these nutrients can lead to an increase in water consumption and wet droppings. When sodium is limiting, birds become flighty and excitable and this can result in cannibalism and increased mortality.
Using sodium bicarbonate to replace part of the salt will limit the level of chloride and has also been shown to improve shell quality especially during periods of heat stress.
Linoleic Acid and Egg Weight
The manipulation of egg weight, that is often necessary due to market demands, can be achieved, in part, with the use of varying levels of the essential fatty acid, linoleic. The effect is only on egg weight and egg numbers should be unaffected.
Linoleic acid is found in vegetable oils such as those derived from maize, soya and sunflower seeds.
Feed Management
Regularly empty, clean and disinfect feed bins and avoid unnecessary build-up of dusty, stale, mouldy and unpalatable feed. Order feed in good time.
On delivery and before discharge confirm the correct product and quantities have been delivered. Take a sample for inspection and retain it for a minimum period of one month.
Inspect sample for grist, colour and smell and compare with previous deliveries. In the event of a significant deviation from the norm inform your feed supplier immediately. Consider exchanging the load.
Periodically a sample should be sent to a specialist laboratory for analysis and for comparison with supplier’s quality control.
Rearing Diet Feed Programme
This consists of a Chick to be fed from day-old to approximately 6 weeks of age during the period of repid supply organ development. Feeding of crumbs during the first three weeks of life can be beneficial to bodyweight gain by avoiding selective feeding. If target weight is not achieved the feeding of this diet should be extended.
The next stage Grower feed should be fed to approximately 12 weeks during the period of maximal structural bone growth. If target weight is not achieved the feeding period should be extended.
The Developer diet is fed to about 15 weeks of age during the period of soft tissue, muscle and fat growth. Above target weight during this period will result in excessive fat deposition, delayed maturity and increase in double yolk eggs and prolapse.
Pre-Lay Diet
A pre-lay diet is recommended to follow the Developer at about 15 weeks of age or at approximately 2 weeks before the first egg is laid.
This diet, with a higher calcium (2%) and available phosphorus (0.40%), is designed to help build up the medullary bone reserves that augment the dietary calcium supply when the shell is being formed and also to help prevent osteoperosis.