Optimum Level of Diet Nutrient for Laying Hens
In general, birds over-consume energy with higher-energy diets, and they will have difficulty maintaining normal energy intake when diets of less than 2,600 kcal ME/kg are offered. In most instances, underconsumption rather than overconsumption is the problem, and so use of higher-energy diets during situations such as heat stress may help to minimize energy insufficiency.
The majority of the world’s laying hens are kept in locations where heat stress is likely to be a major concern at some stage during the production cycle. The problem relates to birds not consuming enough feed at this time, although there are also some subtle changes in the bird’s metabolism that affect both production and shell quality. The key to sustaining production in hot climates is to maintain a positive energy balance. This may involve the use of higher nutrient-dense diets, greater use of fat and synthetic amino acids, texturing of diets, more frequent feeding and perhaps midnight feeding.
Eggshell quality is invariably the number-one issue in layer management today. The important nutritional considerations are levers of calcium, phosphorous and vitamin D3, although it is difficult for a bird to deposit an adequate shell around an egg with poor albumen quality.
There is considerable discussion about the optimum level of calcium to be used and the source of this calcium. Undoubtedly, layers require more calcium today since it is not uncommon to have flock average productions of 330 eggs per year. After 40 weeks of age, at least 50% of supplemental calcium should be as large-particle limestone or oystershell.
Egg composition can be influenced by nutrition. Yolk color in controlled by intake of xanthophylls, and more recently, there has been interest in enriching eggs with lutein as it relates to preventing macular degeneration in humans. Birds fed 10% flaxseed produce eggs with more than 300 mg omega3 fatty acids, while inclusion of 1 – 2 % fish oil is the best way to enrich eggs with DHA.
April 30 2008 08:31 am | Poultry