OFFAL GROWTH IN YOUNG AND MATURE DAIRY COWS

Publisher Website
Google Scholar
Abstract
Nineteen young and eighteen mature lean Holstein cows were purchased from a commercial source and fed a high energy diet ad libitum based on high moisture corn and haylage. Six young and six mature cows were slaughtered at the start of the trial to give an estimate of the initial weight of the offal components. After 68 days on feed, two young cows and two mature cows were slaughtered on a weekly basis until the conclusion of the trial. The offal components were weighed fresh and the alimentary components emptied of digesta. The growth pattern of each offal component relative to empty body weight was estimated from the allometric equation (Y = aXb). Growth coefficients were homogeneous between young and mature cows, indicating that cow age did not influence the relative growth of offal. The internal organs concerned with vital body functions tended to be related to empty body weight to the power of 0.67, which is proportional to the basal metabolic rate. The internal fat depots, however, all had growth coefficients in excess of one. At a constant empty body weight young cows had heavier hides (P < 0.5) and tended to have less hot carcass weight (5.4 kg) than mature cows.