Feed is made up of 85-90% grains, such as wheat, sorghum, barley, oats, lupins, soybean meal, canola and other oilseed meals and grain legumes. For this reason, international grain prices affect the cost of production very significantly.
Meat chicken diets are formulated to strict nutritional standards. A rough guide to the specifications of some of the key nutrients needed by a growing meat chicken is:
| Nutrient Specification of a Broiler Diet (Grower) | |
| Energy | 13 MJ/kg |
| Crude Protein | 20.5% |
| Lysine (digestible) | 1.1% |
| Total sulphur amino acids (digestible) | 0.7% |
| Calcium | 0.9% |
| Phosphorous (available) | 0.4% |
| Sodium | 0.2% |
| Chloride | 0.2% |
Generally speaking, cereal grains provide the energy component of the diet, and soyabean meal, canola meal and meat and bone meal primarily provide the protein. In some areas, grain legumes such as lupins are used as a component of broiler diets where they have the dual role of supplying energy and protein. Vegetable oils or animal fats (such as tallow) might be included in the diet to provide additional energy.
Meat chickens have very specific requirements for particular amino acids, which are the ‘building blocks’ of proteins. The amino acids lysine and methionine are also added to diets because they are generally not present in sufficient amounts in the grains and protein sources to meet the nutritional needs of the birds. Meat chicken diets are also fortified with additional vitamins and minerals and, where necessary, other essential amino acids to ensure that the broilers’ very precise requirements for these nutrients are met.
A ‘typical’ broiler feed might look something like the following.
| Composition of a Typical Broiler Feed |
%
|
| Wheat |
45.0
|
| Sorghum |
25.0
|
| Soyabean Meal |
12.0
|
| Canola Meal |
8.0
|
| Meat & Bone Meal |
7.0
|
| Tallow |
2.0
|
| Lysine |
0.3
|
| Methionine |
0.2
|
| Vitamins & Trace Minerals |
0.5
|
| TOTAL |
100
|
As the chicks grow, the composition and form of the feed is changed to match their changing nutritional needs and increasing mouth size. The ‘starter’ feed, which is in small crumbles just big enough for baby chicks to eat, is replaced with ‘grower’ feed as soon as they are large enough to eat fully formed pellets. After about 25 days, the chickens move on to a ‘finisher’ feed, and then often to a ‘withdrawal’ feed just before harvest.
Pelletized Feed Production
It is the best choice to feed poultry animals with pellets feed. During the feed pellet production, ingredients are ground, mixed together, steam conditioned and compressed into beak sized, well-formed pellets. The high temperatures applied in pelleting kill many bacteria that may be in the feed ingredients, essentially sterilising the feed. Some companies include whole grain mixed with pellets.
A flow diagram of the processes involved in the manufacture of chicken feed in a typical, large feed mill is below.
Corn fed and grain fed chicken is produced as the name indicates by feeding chickens a substantial diet of corn resp. grain. All chickens are fed grains as a major part of their diet. In Australia, the grain is mainly wheat and sorghum. The grains used will depend on the local availability so that in the US, for example, corn is the staple ingredient rather than wheat. Corn-fed chicken tends to have a slightly yellow appearance.
