Feeds for poultry

Poultry feeding is one of the important aspect of poultry science. Poultry feeds are of three types

1. Starting poultry feed: An all mash ration to be fed to chicks upto the age of 8 weeks.

2. Growing poultry feed: A ration to be fed to growing chickens after 8 to 20 weeks or until laying commences.

3. Laying poultry feed: A ration to be fed to laying birds after 20 weeks onwards or after laying commences.

Following are the nutrient constituents of poultry feeds

Proteins: In poultry, the products produced consists mainly of protein. On a dry weight basis the carcass of an 8 weeks old broiler is more than 65% protein and the egg contents are about 50% protein. Typical broiler rations will contain from 22 to 24% protein and in layers ration the amount varies between 16-17%.

Source: Meat scraps (lysine), fish meal (lysine, methionine), poultry by-product meal (tryptophan, lysine), blood meal, liver and glandular meal, feather meal (hydrolyzed), animal tankage, milk products, cottonseed meal, peanut meal, soybean meal, sesame meal, sunflower seed meal.

Carbohydrates: The main function of carbohydrates in the diet is to provide energy to the animal. The polysaccharides of major importance are starch, cellulose, pentosans and several other complex carbohydrates. Although cellulose and starch are composed of glucose units, chickens possess enzymes that can hydrolyze only starch. Cellulose, therefore, is completely indigestible. Cereal grains and their by-products are excellent source of starch and thus constitutes a bulk of poultry ration.

Source: Corn, sorghum grains (milo) barley, rye, oats, wheat, wheat middlings, various grain by-products.

Fats: Fats make up over 40% of the dry egg and about 17% of the dry weight of a broiler. Although fats supply concentrated form of energy (2.25 times more energy than carbohydrate and protein) their inclusion as true fats or oils in the ration is seldom practised because of high cost and the risk of rancidity which develops on prolong exposure to air, heat, sunlight, etc. Most feed ingredients (maize, barley, safflower, milo, wheat, rice, bran, etc.) contain 2-5% fat and that is enough for the inclusion of one essential fatty acid (Linoleic acid), which must be present in the young growing chicks or they will grow poorly, have an accumulation of liver fat and be more susceptible for respiratory infection. Laying hens with diets deficient in linoleic acid will lay small eggs that will not hatch well.

Source: Animal tallow (beef), lard, corn-oil, other vegetable oils.

Minerals: The body of the chicken and the egg excluding shell contain nearly 4 and 1% mineral matter respectively. The elements known to be required in the diet of poultry are calcium, phosphorus, sodium, potassium, magnesium, chlorine, iodine, iron, manganese, copper, molybdenum, zinc and selenium. Usually the grains and vegetable protein ingredients are relatively poor in mineral contents when compared with those of animal protein feed stuffs. The common mineral supplements in poultry feed are as follows: -

1. Limestone

2. Bone meal

3. Oyster shell

4. Sodium chloride

5. Dicalcium phosphate

6. Manganese sulphate

7. Potassium iodide

8. Superphosphate.

Source: Meat scraps, fish meal, milk products, ground limestone (calcium), ground oyster shells (calcium), dicalcium phosphate (calcium, phosphorus), defluorinated rock phosphate (phosphorus, calcium), steamed bone meal (phosphorus, calcium), salt (sodium, chlorine, iodine), manganese sulfate (manganese), manganese oxide (manganese), zinc carbonate (zinc), zinc oxide (zinc).

Vitamins:

Vitamins most commonly function as coenzymes and regulators of metabolism. The 13 vitamins required by poultry have been summarised in tabular form. Apart from natural sources, commercial vitamin mixture suitable for poultry are also available. One point to remember, of course, is that the natural vitamins are likely to have other factors associated with them. These may be other recognised nutrients or they may be unidentified factors. Diets continuously deficient in any one of the required vitamins will seriously tell initially upon the egg production and then the life of the chickens.

Source: Yeasts, fish solubles, distillers’ solubles, liver meal, alfalfa meal, milk by-products.

Feed additives: Additives are never nutrients. They either singly or in combinations are added to a basic feed, usually in small qualities for the purpose of fortifying these with certain nutrients or stimulants or medicines. Often they are called "non-nutrient" feed additives.

Following are some modern feed additives used for poultry –

Recommended range of proportion of poultry feeds.

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