ESTIMATES OF MATURING RATES AND MASSES AT MATURITY FOR BODY COMPONENTS OF SHEEP

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 slaught er ages. The data were fit with a nonlinear function Y(t) = A(1 - Be(- kt)) to provide estimates of rates of maturing (k) and weight at matur ity (A) for components of interest. Except for the testes, all tissues met the convergence criterion. The proportion of offal components rel ative to empty BW was greatest at birth and steadily declined after th is time. Rates of maturing for visceral organs (except for the heart) and the protein constituent of the offal were of greater magnitude tha n the carcass and nonprotein constituents of both the offal and carcas s. Estimated maturing rate and weight at maturity for lipid of the car cass exceeded corresponding estimates of the offal lipid. Evidence was provided suggesting that the developmental patterns of body component s may be established by functional demand.