Success of the feeding program should be measured by how it achieves the breeder’s goals for proper weight and development specific to each strain. Feed and the length of time required to attain certain weights in pullets and turkeys are presented in the growth and feed tables elsewhere in this chapter ( see Nutritional Requirements of Poultry Nutritional Requirements of Poultry read more ). The figures in these tables can be used as a guide to estimate the amount of feed required but will vary considerably because of differences in the nutrient density of feed, strain or breed of bird, amount of feed wasted, and environmental temperature.
Most diets used to feed poultry are nutritionally “complete” and commercially mixed, ie, prepared by feed manufacturing companies, most of which employ trained nutritionists. The formulation and mixing of poultry feeds requires knowledge and experience in purchasing ingredients, experimental testing of formulas, laboratory control of ingredient quality, and computer applications. Improper mixing can result in vitamin and mineral deficiencies, lack of protection against disease, or drug toxicity.
The physical form of the feed influences the expected results. Most feeds for starting and growing birds are produced as pellets or crumbles. In the pelleting process, the mash is treated with steam and then passed through a suitably sized die under pressure. The pellets are then cooled quickly and dried by means of a forced air draft. The conditions under which pelleting occurs (eg, use of an expander rather than an extruder, exposure to high temperature, use of soft pellets) have an important effect on the nutritional quality of the pellets or of the crumbles produced by crushing the pellets.