The official Norwegian Red (NR) Total Merit Index (TMI) is an outstanding overall index that should be used to select NR sires for use with the NR population. This is the main purpose of the NR TMI. However, the NR TMI might not be the best index for selecting NR sires for crossbreeding in many herds around the world.
Geno has developed two additional indexes designed to help herds choose NR sires for specific herd types. These two indexes rank bulls different compared to the NR TMI and the indexes might be more suitable than the TMI for herds with economic and management circumstances that differ from what is found in Norway.
Index for high production herds
The first of these indexes is designed for high production herds that generally house and maintain cows in a confined setting where cows are few high energy rations without intake restrictions or limitations.
This index for high production herds places approximately half the emphasis on fat yield and protein yield but it also places significant emphasis on udder conformation, daughter fertility and udder health. This index is likely more suitable than the TMI for selecting NR sires to use in crossbred herds where cows are fed for top performance.
Top bulls based on this index will produce daughters that have outstanding solids production, excellent fertility and long lasting udders.
Index for grazing herds or other low input herds
The second of these indexes, the grazing index, is designed for herds that generally maintain cows on pasture for much of the year or manage cows with limited inputs.
This index for grazing and low input herds places heavy emphasis on fertility as well as fat and protein percentages. It also places some emphasis on udder health, udder conformation and overall fat and protein production.
This index is likely more suitable than TMI for selecting NR sires to use in grazing herds or other herds where feed intakes or feed concentrate intakes are restricted due to the herd management situation.
Top bulls based on this index will have daughters with excellent fat and protein production from grass or forage based production and they will have daughters with superior fertility and udder health.