Genetic evaluations of the
PTAs for yield and type are combined into a
Production Type Index (PTI) that represents the economic merit of the traits evaluated for the animal. Fat Corrected Milk (FCM), based on an accepted conversion formula for milk represents yield, and
PTA for adjusted final score.
Two PTIs with differing weights are provided by ADGA to dairy goat producers:
- one with yield weighted twice as much as type (PTI2:1)
- one with type weighted twice as much as yield (PTI1:2)
PTIs are a relative index; the numbers are relative to breed averages. It is important to remember that comparisons should not be made between breeds.