Browsing by Author "Sampolahti, Sani"

In this study the economic values for the breeding goal traits for Finnish Ayrshire cattle were determined by the bioeconomical model. Additionally, the economic value was determined for a new trait, feed efficiency, which was modelled as residual feed intake (RFI). Feed efficiency was added to breeding goals because of intrest in reduction of harmful environmental effects of dairy cattle production. The effect of increasing feed costs on the economic weights was also studied. Economic values were determined by the program ECOWEIGHT. The bioeconomical model included 21 traits, which can be divided a few categories: milk production traits, growth and carcass traits and functional traits (calving difficulty, stillbirth, calf mortality in the rearing period, fertility traits, productive lifetime of cows, incidence of clinical mastitis, somatic cell score (SCS) and residual feed intake (RFI)). Economic values and standardized economic weights were defined for the traits. Profitability of the milk production was negative (?13,3%), when the subsidies were not included in the calculations. Adding RFI didn’t have any effect on the economic values of the other traits and it didn’t change the order of the traits in standardized economical weight. The marginal economic values for RFI of cows and heifers were ?55,8 and ?24,9 €/kg/d, respectively. The highest relative economic weights was found for 305-d milk (36%), protein (14%), fat (9%), mature weight (7%) and calving interval (5%). Relative economic weights for RFI of cows and heifers were 4,6% and 1,5%, respectively. An increase in the feeding costs (10, 30 and 50%) changed the order of the traits in standardized economical weights. The weights of milk production traits were decreased and the weights of growth traits, RFI and calving interval were increased. RFI of cows was the fifth important trait when feeding costs increased 30%. According to the results of this study would be beneficial, especially if the relative im-portance of feed efficiency will increase in the future due to increasing feed costs or in-creasing requirements to mitigate the environmental impact of milk production. However, more research will be needed before adding RFI to the breeding goals.