Comparison of single- and multiple-trait selected sires--response of heifer growth

Body weights and linear body measurements were on 386 heifers whose sires were selected according to two criteria: 1) Yield, selection only on milk yield Predicted Difference from daughters' first lactations; 2) Merit, selection on a combination of milk yield Predicted Difference (all daughters), udder type, and percentage of daughters leaving herd in first lactation. No significant differences existed between Yield and Merit heifers for body weights at various ages through first calving or in heart girth or withers height through 18 mo of age. Heifers born to dams first parity were lighter at birth but were not significantly different from other parties of dam for weight, withers height, or heart girth at later ages. Differential selection for milk yield as in this study did not change body weight of heifers.