The size of dairy heifers

Abstract

1. A field investigation to estimate the mean weight and chest girth of unserved Friesian, Ayrshire and Dairy Shorthorn heifers of between 3 and 24 months of age was carried out.2. Data from 1,620 Friesians, 725 Ayrshires and 455 Dairy Shorthorns in the North of England were obtained, with a mobile weighbridge and a. spring-loaded steel tape in the winter 1958–59.3. It was found that on average the Friesians were heavier and had a greater chest girth than the Ayrshires and Dairy Shorthorns, which did not differ significantly.4. These heifers were apparently reared on planes of nutrition which, judged by conventional feeding standards, may be described as ‘low’.5. After eliminating the linear effect of age by covariance analysis, highly significant differences between herds and between sires in weight and chest girth were found.6. The investigation demonstrated the feasibility and value of collecting field data on body size.

Environmental and managerial factors affecting the growth of Friesian heifers from six months of age to calving

“…It is also considered that the live weights and live-weight gains of the young stock at the Institute lie well within the range of the normal growth curve. In this connexion Hodges et al (1960), in a survey of the live weights of 1600 Friesian heifers in north country herds aged from 3 to 6 months and from 6 to 24 months, found mean live-weight gains of 1-4 lb/day and 0-9 lb/day respectively, results very similar to those reported here.…”

“…This is in contrast to the many studies of live weight in relation to age in which each animal is weighed only once (e.g. Hodges, O'Connor & Clark, 1960).…”