Nutrient requirements of poultry
From Poultry Hub
Poultry diets must be formulated to provide all of the bird’s nutrient requirements if optimum growth and production is to be achieved. There are six classes of nutrients:
- Carbohydrates – the major source of energy for poultry. Most of the carbohydrate in poultry diets is provided by cereal grains.
- Fats – provide energy and essential fatty acids that are required for some body processes.
- Proteins – required for the synthesis of body tissue (particularly muscle), physiological molecules (such as enzymes and hormones), feathers and for egg production. Proteins also provide a small amount of energy.
- Vitamins – organic chemicals (chemicals containing carbon) which help control body processes and are required in small amounts for normal health and growth.
- Minerals - inorganic chemicals (chemicals not containing carbon) which help control body processes and are required for normal health and growth.
- Water.
Contents |
Factors affecting the nutrient requirements of poultry
The nutrient requirements of poultry are affected by a large number of factors, including:
Genetics (the species, breed or strain of bird)
Different species, breeds or strains of bird have different average body sizes, growth rates and production levels and will also absorb and utilise nutrients from feed with different levels of efficiency, leading to different nutrient requirements. As the genetics of commercial poultry is constantly changing so are their nutrient requirements. Consequently, breeders of commercial poultry provide information on the specific nutrient requirements for the birds they sell.
Age
Nutrient requirements are related to both body weight and the stage of maturity.
Sex
Prior to sexual maturity the sexes have only small differences in their nutrient requirements and males and females can usually be fed the same “compromise” diet to achieve acceptable growth rates. Differences in nutrient requirements are larger following the onset of sexual maturity and significantly different diet formulations are then required for each sex.
Reproductive state
The level of egg production in hens and sexual activity in males will affect nutrient requirements.
Ambient temperature
Poultry have increased energy requirements to maintain normal body temperature in cold ambient temperatures and the opposite in hot ambient temperatures. The process of digestion of food produces body heat and the amount of heat produced will vary according to the nutrient composition of the diet. This is called the heat increment of the diet. In cold temperatures it may be desirable to formulate a diet with a higher heat increment and the opposite in hot temperatures.
Housing system
The type of housing system will influence the level of activity of the birds and therefore their energy requirements.
Health status
Birds experiencing a disease challenge may benefit from an increase in the intake of some nutrients, most commonly vitamins.
Production aims
Optimal nutrient composition of the diet will vary according to production aims, such as optimising weight gain or carcass composition, egg numbers or egg size. Poultry that are raised for breeding purposes may need to have their energy intake restricted to ensure that they do not become obese.
Nutrient requirements of egg laying chickens
The intake of nutrients is a function of the amount of feed eaten and the nutrient levels in the diet.
Feed consumption
There are a number of factors that influence voluntary feed intake. These are discussed in the Section on Feed intake. Table 1 provides data on typical feed consumption for brown-egg laying hens in relation to body weight.
Table 1. Body weights and associated feed consumption for a brown-egg laying breed
| Age (wk) | Body weight (g) | Feed consumption (kg/100 birds/d) | Age (wk) | Body weight (g) | Feed consumption (kg/100 birds/d) |
|---|---|---|---|---|---|
| 1 | 70 | 0.07 | 40 | 2020 | 23.97 |
| 4 | 310 | 0.61 | 44 | 2040 | 27.25 |
| 8 | 670 | 1.81 | 48 | 2050 | 30.50 |
| 12 | 990 | 3.31 | 52 | 2060 | 33.72 |
| 16 | 1330 | 5.09 | 56 | 2070 | 36.92 |
| 20 | 1720 | 7.50 | 60 | 2080 | 40.11 |
| 24 | 1910 | 11.44 | 64 | 2090 | 43.31 |
| 28 | 1950 | 13.95 | 68 | 2100 | 46.50 |
| 32 | 1980 | 17.31 | 72 | 2100 | 49.69 |
| 36 | 2000 | 20.67 | 76 | 2100 | 52.88 |
Source: Commercial layer management training course
Nutrient levels for layer chick diets
Chicks require a diet that can provide the nutrients needed for rapid growth and feather development. Chick diets (often called starter diets) are relatively high in energy, protein and the vitamins and minerals required for growth and development. Table 2 provides data on typical nutrient levels for layer chick diets.
Table 2. Examples of layer chick diets
| Selected nutrients | 1-diet starter | 2-diet starter | |
|---|---|---|---|
| Chick starter (0-5 weeks) | Chick super starter (0-3 weeks) | Chick starter (3-9 weeks) | |
| ME (MJ/kg) | 11.7 | 12.3 | 11.9 |
| Crude protein (%) | 19.5 | 21.0 | 19.0 |
| Lysine (%) | 0.96 | 1.20 | 1.00 |
| Methionine (%) | 0.39 | 0.50 | 0.43 |
| Linoleic acid (%) | 1.00 | 1.10 | 1.10 |
| Calcium (%) | 1.00-1.25 | 1.00 | 1.00 |
| Available phosphorous (%) | 0.50-0.65 | 0.50 | 0.50 |
Source: Commercial layer management training course
Nutrient levels for layer pullet diets
Once the chicks are fully feathered their energy requirements are reduced. Feeding management for layer pullets aims to maintain a growth rate that will lead to the pullet reaching sexual maturity at the desired age and to avoid obesity. The stage at which a pullet will start laying eggs is affected by age, bodyweight and day length.
Layer pullet diets have lower energy and protein levels than chick diets on a percentage basis. Different breeders recommend different feeding strategies for their birds, including the number of different diets fed during the pullet growing stage. Many breeders recommend a pre-lay diet that increases some of the nutrient levels, such as calcium, that will be required by the bird when it begins to lay eggs. Table 3 provides data on typical nutrient levels for layer pullet diets.
Table 3. Examples of layer pullet diets
| Selected nutrients | 1-diet | 2-diet grower | |
|---|---|---|---|
| Pullet grower (5-19 weeks) | Pullet grower (9-14 weeks) | Pre-layer (14 weeks – 10% lay) | |
| ME (MJ/kg) | 10.9 | 11.1 | 11.5 |
| Crude protein (%) | 15.0 | 16.0 | 16.0 |
| Lysine (%) | 0.65 | 0.67 | 0.78 |
| Methionine (%) | 0.28 | 0.30 | 0.36 |
| Linoleic acid (%) | 0.80 | 0.90 | 1.10 |
| Calcium (%) | 1.00-1.25 | 1.00 | 2.00 |
| Available phosphorous (%) | 0.50-0.65 | 0.45 | 0.45 |
Source: Commercial layer management training course
Nutrient levels for layer diets
The aim of layer diets is to optimize egg production, provide the nutrition required to safeguard health, maintain the desired bodyweight. This can be in terms of either in terms of egg numbers, egg size or egg mass. As with layer pullets, different breeders recommend different feeding strategies for their birds, including the number of different diets fed during the laying stage. Calcium is increased in the ration for egg shell formation. Table 4 provides data on typical nutrient levels for layer diets.
Table 4. Examples of layer diets
| Nutrients | Units | Phase 1 diet (19-50 weeks) | Phase 2 diet (50+ weeks) |
|---|---|---|---|
| ME | MJ/kg | 11.5-11.7 | 11.4-11.5 |
| Crude protein | mg/d | 19.5 | 18.5 |
| Lysine | mg/d | 880 | 840 |
| Methionine | mg/d | 430 | 410 |
| Linoleic acid | g/d | 1.6 | 1.6 (max) |
| Calcium | g/d | 3.9-4.1 | 4.2-4.6 |
| Available phosphorous | g/d | 0.44 | 0.38 |
Source: Commercial layer management training course
Nutrient requirements of meat chickens
The intake of nutrients is a function of the amount of feed eaten and the nutrient levels in the diet.
Feed consumption
There are a number of factors that influence voluntary feed intake. These are discussed in the Section on Feed intake. Table 5 provides data on typical feed consumption for broiler chickens in relation to age and sex.
Table 5. Cumulative feed consumption for male and female broilers (g)
| Age (weeks) | Male | Female |
|---|---|---|
| 0 | 0 | 0 |
| 1 | 135 | 131 |
| 2 | 425 | 404 |
| 3 | 912 | 848 |
| 4 | 1616 | 1490 |
| 5 | 2576 | 2228 |
| 6 | 3717 | 3229 |
| 7 | 4998 | 4310 |
| 8 | 6430 | 5475 |
| 9 | 8007 | 6721 |
Source: Commercial meat chicken management training course
Nutrient levels for broiler diets
Feeding strategies for broiler chickens will vary depending on the target market for the final product. Strategies for feeding broilers destined for the whole bird market will differ from strategies for broilers destined to be sold as pieces. Furthermore, the nutrient intake of fast growing broilers must be carefully controlled to prevent metabolic diseases such as ascites and leg weakness. Table 6 provides data on typical nutrient levels for broiler diets.
Table 6. Examples of broiler diets
| Nutrients | Pre-starter | Starter | Grower | Finisher/Withdrawal | |||
|---|---|---|---|---|---|---|---|
| Crude protein (%) | 23 | 22 | 20 | 20 | 18 | 18 | 16 |
| ME (kcal/kg) | 3050 | 3050 | 2900 | 3150 | 3000 | 3200 | 3050 |
| Lysine (%) | 1.35 | 1.20 | 1.05 | 1.10 | 0.90 | 0.90 | 0.80 |
| Methionine (%) | 0.52 | 0.48 | 0.42 | 0.44 | 0.38 | 0.37 | 0.36 |
| Calcium (%) | 1.0 | 0.95 | 0.95 | 0.92 | 0.92 | 0.90 | 0.90 |
| Available phosphorous (%) | 0.45 | 0.42 | 0.42 | 0.40 | 0.40 | 0.38 | 0.38 |
| Sodium (%) | 0.19 | 0.18 | 0.18 | 0.18 | 0.18 | 0.18 | 0.18 |
Source: Commercial Poultry Nutrition, 2nd Ed. S. Leeson and J. D. Summers. Pub University Books, Canada, 1997
Water consumption rates for chickens
Water is an essential nutrient for life. Water consumption can be limited if the water is too hot or is contaminated with excess minerals. Water and food consumption rates are interdependent and so reduced water intake can also lead to reduced food intake. Tables 7 and 8 provide data on typical water consumption levels for layers and broiler, respectively.
Table 7. Typical daily water consumption for layers (litres per 1000 birds)
| 20oC | 32oC | ||
|---|---|---|---|
| Layer pullet | 4 weeks | 50 | 75 |
| 12 weeks | 115 | 180 | |
| 18 weeks | 140 | 200 | |
| Laying hens | 50% production | 150 | 250 |
| 90% production | 180 | 300 |
Source: Commercial layer management training course
Table 8. Typical daily water consumption for broilers (litres per 1000 birds)
| Age | 20oC | 32oC |
|---|---|---|
| 1 weeks | 24 | 40 |
| 3 weeks | 100 | 190 |
| 6 weeks | 240 | 500 |
| 9 weeks | 300 | 600 |
Source: Commercial meat chicken management training course
Nutrient requirements of turkeys
Nutrient levels for turkey diets
The principles behind formulating turkey diets are similar to those for broiler chickens. Table 9 provides data on typical nutrient levels for turkey diets.
Table 9. Examples of turkey diets
| Nutrients | Starter 1 | Starter 2 | Grower 3 | Grower 4 | Developer 5 | Finisher 6 |
|---|---|---|---|---|---|---|
| Crude protein (%) | 28 | 26 | 23 | 21.5 | 18 | 16 |
| ME (kcal/kg) | 2900 | 3000 | 3050 | 3100 | 3200 | 3300 |
| Lysine (%) | 1.70 | 1.60 | 1.50 | 1.30 | 1.15 | 1.00 |
| Methionine (%) | 0.62 | 0.55 | 0.50 | 0.47 | 0.42 | 0.34 |
| Calcium (%) | 1.4 | 1.3 | 1.2 | 1.3 | 1.0 | 0.90 |
| Available phosphorous (%) | 0.7 | 0.6 | 0.5 | 0.6 | 0.5 | 0.40 |
| Sodium (%) | 0.18 | 0.18 | 0.17 | 0.17 | 0.17 | 0.17 |
Source: Commercial Poultry Nutrition, 2nd Ed. S. Leeson and J. D. Summers. Pub University Books, Canada, 1997
Further information
- Commercial Poultry Nutrition, 2nd Ed. S. Leeson and J. D. Summers. Pub University Books, Canada, 1997
