Feed formulation is the process of quantifying the amounts of feed ingredients that need to be put together, to form a single uniform mixture (diet) for poultry that supplies all of their nutrient requirements. It is one of the central operations of the poultry industry, in view of its role in ensuring good nutrition. Feed costs account for more than 70% of the total production costs for most types of poultry, so it is important that returns are maximised through use of adequate diets.
Feed formulation is a central operation in poultry production, ensuring that feed ingredients are economically used for optimum growth of chickens. It requires a good knowledge of poultry and feed ingredients. Most large-scale poultry farmers depend on commercial feed mills for their feeds, to obviate the need to do their own formulations or feed preparation. It is therefore essential that formulations are accurate, to ensure a large number of flocks are not adversely affected.
Feed formulation is both a science and an art, requiring knowledge of feed and poultry, and some patience and innovation when using formulae. Typical formulations indicate the amounts of each ingredient that should be included in the diet, and then provide the concentration of nutrients (composition) in the diet. The nutrient composition of the diet will indicate the adequacy of the diet for the particular class of poultry for which it is prepared (e.g. egg layers, meat chickens or breeders). It is common to show the energy and protein contents of the diet but comprehensive information on concentrations of mineral elements and amino acids may also be provided. Since lysine is a key amino acid for poultry, the concentrations of the other amino acids may be related to it. Because some nutrients interfere with the utilisation of other nutrients, relationships between nutrients, particularly amino acids, also show if each of the nutrients will be used efficiently.
Why are diets formulated for poultry?
One of the reasons for formulating diets for poultry has already been identified, i.e. to produce a single uniform feed that can be delivered efficiently to poultry. The production rates expected on modern poultry farms also dictate that the dietary requirements of poultry be carefully identified and precisely met. Diet formulation enables the poultry industry to maintain some uniformity in levels of production. Industry nutritionists tend to use the same formulations over relatively long periods of time, so that the quality of the product (meat or eggs) remains stable over time. The product quality can also be easily predicted if the same diet formula is used and all other factors remain unchanged. It is worth stating that chickens are able to select from different ingredients, placed separately, in order to grow and lay normally. Such a practice is known as choice feeding, and is practised on a limited scale by some poultry producers. However, choice feeding is cumbersome and cannot be economically applied in large-scale modern commercial situations without modifications to the infrastructure.
Although it does not appear to be a part of the feed formulation process, the first step in feed formulation is evaluation of ingredients. The requirements of the chickens for nutrients such as protein, mineral elements (e.g. calcium), and energy need to be identified. These requirements vary with age, type of chickens (layer or meat type), level of production, etc. It is also important to obtain and compare the prices of feed ingredients, in order to reduce the overall cost of the diet.
With this knowledge, mathematical formulae are used to derive the amounts of each ingredient that need to be included in the mixture, i.e. the diet. When using only a few ingredients, the formulae are simple, but a few ingredients are rarely able to supply all the nutrients that will meet the requirements of the bird, so several ingredients are used, requiring complex formulae. Some of these formulae have been built into computer programs, which enable the rapid processing of values that should be included in the formulation. Computer programs also make it easy to check if nutrient requirements are met.
It is important, however, to evaluate the diet in the laboratory or feed it to a small group of chickens to confirm the adequacy of the diet. This may not be necessary if the actual composition of the ingredients used is known and the actual nutrient composition can therefore be obtained. Although the average composition of many common ingredients is known, ingredients tend to vary between batches (e.g. in drought years cereals can be lower in quality).
