Radha Bai, Department of Animal Nutrition, LUVAS, Hisar
Shabnam, Department of Animal Nutrition, LUVAS, Hisar
Komal, Department of livestock Production and Management, LUVAS, Hisar
The objective of feed formulation is to derive a balanced diet that will provide appropriate quantities of biologically available nutrients required by the bird. In addition to energy and protein, formulations contain supplements to provide minerals, vitamins and specific amino acids. These supplements must be added to all diets as they provide essential nutrients necessary for health and performance. Modern feed formulations also contain a diverse range of non-nutritive additives, which may not be essential but have an important bearing on performance and health. Feed supplements and additives are used in only small quantities, and it is particularly important that they are mixed carefully with the main ingredients so that they are evenly distributed.
Nutritional supplements used in poultry feed formulations:
Only part of bird’s mineral requirements is provided by the natural feedstuffs in their diets. Mineral supplements must therefore be included in feed formulations.
Major minerals: Poultry require relatively large amounts of some minerals, such as calcium, phosphorus and sodium. Calcium and phosphorus are needed for normal growth and skeletal development, and poultry have unusually high requirements for calcium during the period of egg production, for the formation of strong egg shells. The calcium supplements commonly used in poultry feeding are limestone, crushed sea shells or sea-shell flour. Limestone powder can be included at no more than 3 percent, because higher levels will lower feed intake. It is therefore necessary to provide the extra calcium needed by high-producing layers as shell grit or limestone grit.
To meet the phosphorus needs of poultry, formulations must be supplemented with inorganic phosphorus sources. The inorganic phosphates used in poultry diets are dicalcium phosphate, bone meal, rock phosphate, defluorinated phosphate and tricalcium phosphate, all of which supply both calcium and phosphorus.
A recent development in phosphorus nutrition has been the availability of commercial phytase enzymes, which assist the bird’s digestion and utilization of the phosphorus bound in phytic acid. This enzyme improves the availability of phosphorus from plant materials and reduces the need for inorganic phosphates in feed formulations. This enzyme is a non-nutritive additive.
Common salt is included in all diets as a source of sodium and an appetite stimulant. Salt is added in poultry diets at levels of 0.2 to 0.4 percent. Excessive salt increases water consumption and leads to wet excreta. The use of salt can be lowered or even omitted if more than 5 percent fishmeal is used in the diet.
These elements are required in the diet at concentrations in trace amounts, usually about 0.01 percent. Trace minerals (zinc, copper, iron, manganese, cobalt, selenium) are therefore usually added in the form of propriety premixes.
Vitamin supplements: All vitamins, except vitamin C, must be provided in the diet. Vitamins are required in only small amounts, and are usually provided as vitamin premixes. Although vitamin premixes represent only 0.05 percent of the diet, they can have a large effect on bird performance.
Crystalline amino acids:
Pure forms of individual amino acids are now commercially available. Currently the limiting amino acids in poultry diets – methionine, lysine, threonine and tryptophan included in poultry diets to balance dietary amino acid levels. Amino acid supplements now play a very important role in improving protein utilization in animal feeding.
Non-nutritive additives used in poultry feed formulations:
So, these feed additives play a crucial role in poultry diet in terms of by improving the health and productivity of animals, enhancing the quality, palatability, digestibility and utilisation of feed, improve the growth efficiency and decrease disease chances and hence improve overall performance of birds.