Important changes are taking place in the mid-western egg industry. Changes in Iowa are broadly representative of the transformations taking place in this industry throughout the region. One of the most significant changes has been the decline in the number of farms producing eggs. In 1940, 198,000 Iowa farms -or 93 percent of all farms-reported chickens on hand. In 1950, the number was 174,000, or 86 percent. By 1959, there had been a further decline to 68 percent.

Along with the changing number of farms producing eggs, there has been a change in the sizes of flocks on farms. In Iowa, the proportion of very small flocks has remained nearly constant. In 1940 and 1950, roughly 13 percent of all Iowa flocks had fewer than 50 hens. This rose to about 15 percent in 1959. A sharp decline in medium-sized flocks of 50 to 400 hens occurred in the same period, from 86 percent in 1940 to 71 percent in 1959. Numbers of flocks larger than 400 hens have shown substantial increases, as shown in table 1 (1, 8, 14).

Small flocks (less than 50 hens) are of little commercial importance. They are maintained mainly to supply the farm household with eggs for consumption. Farm flocks of 50 to 400 hens are most numerous; they have served as a means of acquiring a steady flow of cash for the household and an outlet for family labor on the family farm. For our study, flocks of this size take on great importance; they are the main component of the existing production pattern. Flocks larger than 400 hens are increasing rapidly and will probably continue to increase because of economies of scale in egg production and possible economies in marketing operations. This study emphasizes these larger flocks to ascertain their relationship to assembly and processing costs.