By Pryce , J. E. and Simm, G. and Veerkamp, R. F., Stocarstvo, 1999
Description
Genetic parameter estimates for milk yield, calving interval, and mastitis and lameness incidence were calculated from analysis of data from two UK recording schemes using two selection indices. The goal of both indices was to optimize responses to selection for production, using economic values of -0.03 o/kg, 0.60 o/kg and 4.04 o/kg for milk, butterfat and protein yields respectively. One index was used to maximize response in production (PIN) and the other was restricted to zero genetic change in several health and fertility traits (RIN). Selection on PIN was predicted to increase calving interval by 2.78 days per unit selection differential. Mastitis and lameness were expected to increase by 0.018 and 0.007 cows with one or more cases of mastitis and lameness respectively. Selection using RIN was expected to result in 11% less overall economic response in production than PIN
Genetic parameter estimates for milk yield, calving interval, and mastitis and lameness incidence were calculated from analysis of data from two UK recording schemes using two selection indices. The goal of both indices was to optimize responses to selection for production, using economic values of -0.03 o/kg, 0.60 o/kg and 4.04 o/kg for milk, butterfat and protein yields respectively. One index was used to maximize response in production (PIN) and the other was restricted to zero genetic change in several health and fertility traits (RIN). Selection on PIN was predicted to increase calving interval by 2.78 days per unit selection differential. Mastitis and lameness were expected to increase by 0.018 and 0.007 cows with one or more cases of mastitis and lameness respectively. Selection using RIN was expected to result in 11% less overall economic response in production than PIN
We welcome and encourage discussion of our linked research papers. Registered users can post their comments here. New users' comments are moderated, so please allow a while for them to be published.