Genetic Correlations Among Body Condition Score, Yield, and Fertility in First-Parity Cows Estimated by Random Regression Models

摘要

Twenty type classifiers scored body condition (BCS) of 91, 738 first-parity cows from 601 sires and 5518 ma - ternal grandsires. Fertility data during first lactation were extracted for 177, 220 cows, of which 67, 278 also had a BCS observation, and first-lactation 305-d milk, fat, and protein yields were added for 180, 631 cows. Heritabilities and genetic correlations were estimated Using a sire - maternal grandsire model. Heritability of BCS was 0.38. Heritabilities for fertility traits were low (0.01 to 0.07), but genetic standard deviations were substantial, 9 d for days to first service and calving interval, 0.25 for number of services, and 5/100 for first - service conception.