BeefxDairy breeding values
NAV breeding values for AI beef bulls evaluated on their crossbred offspring from dairy cows (so called BeefxDairy or BxD breeding values) can be used by dairy farmers to select beef bulls across breed for producing crossbred calves that are easily born and have a good growth and carcass quality. Crossbred calves included in the evaluation are from purebred Holstein, Jersey and RDC cows. Up to ten single BxD breeding values can be published for each bull if the publication rules are fulfilled. The single breeding values are combined with economic weights into one of three sub-indices, Birth, Growth or Youngstock survival, which are further combined into the Nordic BeefxDairy Index (NBDI).
Nordic BeefxDairy Index, NBDI
The Nordic BeefxDairy Index (NBDI) describes a beef bull’s economic value based on genetic potential for producing crossbred beef-dairy offspring that give the farmers the best economy. It is composed of three sub-indices, Birth, Growth and Youngstock survival. The length and intensity of the rearing affects the economic values of the growth traits. Each bull gets different values both for the sub-index Growth and for the total merit index NBDI depending on rearing period short (<550 d) or long (>550 d). In general, short rearing period is applied in Denmark and long rearing period in Finland and Sweden.
Birth index includes two breeding values, calf survival and calving ease in later lactations, combined with economic weights.
Growth index, short or long, includes three breeding values, daily carcass gain, carcass conformation score and carcass fat score, combined with economic weights.
Youngstock survival index includes two breeding values, early period and late period combined with economic weights.
NBDI, short or long, includes birth index, growth index, short or long and youngstock survival index, combined with economic weights. How the different breeding values are combined into NBDI is the result of thorough economic calculations and expectations on future production conditions and price relations.
Making the decisions of which AI beef bull to use in your dairy herd based on NBDI gives crossbred calves that are easily born, with good growth and carcass quality and with high survival in rearing period. It gives progress in all included traits. With NBDI you are breeding for improved profit.
More information:
Total Merit Index (NBDI) for beef sires used for dairy cattle, updated 2024