Journal of Animal Science, Vol 71, Issue 11 2952-2957, Copyright © 1993 by American Society of Animal Science

JOURNAL ARTICLE

Estimates of maturing rates and masses at maturity for body components of sheep

T. G. Jenkins and K. A. Leymaster
Roman L. Hruska US Meat Animal Research Center, ARS, USDA, Clay Center, Nebraska 68933-0166.

Weight data for fleece-free empty body, carcass and offal components, and their chemical constituents (protein, water, lipid, and ash) were collected via serial slaughter techniques. Rams sired by a sheep breed of high genetic merit for growth were slaughtered from birth through 48 mo of age. Approximately six rams were killed at each of 13 slaughter ages. The data were fit with a nonlinear function Yt = A(1-Be-kt) to provide estimates of rates of maturing (k) and weight at maturity (A) for components of interest. Except for the testes, all tissues met the convergence criterion. The proportion of offal components relative to empty BW was greatest at birth and steadily declined after this time. Rates of maturing for visceral organs (except for the heart) and the protein constituent of the offal were of greater magnitude than the carcass and nonprotein constituents of both the offal and carcass. Estimated maturing rate and weight at maturity for lipid of the carcass exceeded corresponding estimates of the offal lipid. Evidence was provided suggesting that the developmental patterns of body components may be established by functional demand.