Yield
Yield index describes genetic potential for milk, fat and protein production. It includes breeding values for milk, fat and protein based in kilograms of milk as well as fat and protein (the latter are based on kg of milk and fat and protein percentages.) Information comes from the first three lactations from milk recording.
The goal is to produce milk that corresponds to the dairy payment systems. Therefore there is positive weight on protein and fat kilos and negative weight on milk kilos. The weighting differs between breeds.
The yield index is included in NTM. In addition breeding values for protein and fat percentage and persistency are published.
Read more about breeding value calculations on the document NAV routine genetic evaluation of dairy cattle – data and genetic models.
Growth
Growth index describes genetic potential for carcass gain and carcass conformation score.
Breeding values are based on slaughter carcass weight and carcass conformation (EUROP scale) from male calves raised with either a short intensive or a long extensive fattening period.
The growth index is included in NTM.
Read more about breeding value calculations on the document NAV routine genetic evaluation of dairy cattle – data and genetic models.