To illustrate the effects that diet ingredient composition can have on dietary
vitamin contents, Table 4 shows the vitamin contents for broiler prestarter
and starter diets based mainly on wheat or maize, using animal or
oilseed meal proteins, and for diets containing other ingredients. Considerable and important variation occurs in the contents of some vitamins, particularly
biotin, nicotinic acid, pyridoxine, cobalamin, folic acid and choline. In
contrast, riboflavin and thiamin contents stay remarkably constant. Similar
variation can be demonstrated for other types of poultry diets.