To develop a modern appraisal of growth for Ayrshire, Brown Swiss, and Milking Shorthorn dairy heifers, data on heart girth and height at withers were collected from 1279 Ayrshire heifers (33 herds), 1819 Brown Swiss heifers (46 herds), and 565 Milking Shorthorn heifers (20 herds), ages 1 to 25 mo, in herds located throughout the US. Means and standard deviations were determined for height and heart girth for each month of age. Third-order regressions on age were fitted to the means to describe height and heart girth. Estimated mean height and heart girth at 6, 12, 18, and 24 mo, in centimeters, were for Ayrshire 98.7 and 118.4, 114.4 and 145.9, 122.8 and 163.2, and 127.6 and 176.4; for Brown Swiss 102.6 and 122.3, 199.4 and 151.3, 128.7 and 168.8, and 134.0 and 182.0; and for milking Shorthorn 98.0 and 119.4, 113.6 and 148.6, 122.6 and 166.6, and 127.7 and 179.9, respectively. These data can be useful to evaluate the heifer rearing program with respect to the growth rates of heifers on an individual farm.
All Science Journal Classification (ASJC) codes
- Food Science
- Animal Science and Zoology