Saved feed sub-index describes genetic potential for saving feed costs from both an improved maintenance efficiency (reduced maintenance requirement) and an improved metabolic efficiency. For both parts, a higher breeding value indicates more saved feed and can be expressed as reduced kilograms of dry matter intake in the first three lactations.
The breeding value for maintenance efficiency describes the genetic ability for saved feed through lower maintenance requirement. Basically, it is related to the body weight of the cow. It is well-known that a larger cow requires more energy for maintenance than a smaller cow. The information for this breeding value is based on weight records from many Nordic cows – either from scale or from tape measurements – in the first three lactations. Further, the body conformation measures stature, body depth and chest width, from linear classification, are used as correlated traits.
The breeding value for metabolic efficiency describes the genetic ability for saved feed through improved feed utilization. This breeding value is based on information about individual feed intake data as well as body weight and milk production.
More about Saved feed:
Genetic evaluation for Saved feed (November 2020)