Uniformity is a very important management tool, as well as a parameter to describe the quality of the brooding, rearing or growing processes in both broilers and breeders.

A high uniformity means that the majority of the birds is in a very small range of body weights, and there is not a lot of difference between the biggest and the smallest birds.

Uniformity in broilers is important because it determines the range of body weights and for instance breast meat yields delivered at the processing line. Processing plants have a certain optimum body weight for the product they want to produce. A high uniformity means that more birds are in the desired weight range.

Uniformity in breeders is important because we have to apply the management (feed and light programs) to the whole flock, where smaller, less developed birds need another management than bigger, more developed birds. If the flock is uniform, the supplied management will be optimum for a higher number of birds.

Uniformity can be described by the percentage of birds in a certain weight range (called: % uniformity) or as a statistical figure that is called coefficient of variation.

Uniformity of a flock is influenced by circumstances as:
- brooding and quality of start
- diseases
- competition for feed (feeder space)
- competition in general (density)
- speed of feed distribution (feeding equipment)
- amount of feed distributed (feeding program)
- separation in weight groups (grading)