作者: M. J. McPhee , J. W. Oltjen , J. G. Fadel , D. Perry , R. D. Sainz
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摘要: The Davis growth model (DGM) simulates and body composition of beef cattle predicts development 4 fat depots. Model evaluation require quantitative data on weights, but sometimes it is necessary to use carcass that are more commonly reported. Regression equations were developed based published interconvert between characteristics kilograms in various depots predict the initial conditions for DGM. Equations include those evaluating relationship following: subcutaneous (SUB, kg) 12th-rib thickness (mm); visceral (VIS, KPH (kg); DNA (g) intermuscular, intramuscular, subcutaneous, empty weight; contributions (kg) intramuscular (INTRA), SUB, VIS total (kg). intermuscular (INTER, contribution was found by difference. linear regression as follows: SUB vs. (n = 75; P < 0.01) with R(2) 0.88 SE 10.00; (kg; n 78; 0.95 2.82; INTER, INTRA, weight 6, 5, 6; 0.08, 0.01, 0.05) 0.57, 0.93, 0.66, 0.03, 0.003, 0.02, respectively; 23; each depot, 0.97, 0.99, 0.61, 1.41, respectively. All empirical except challenged independent sets 12 10 9 depots). mean biases -2.21 (P 0.12) 2.11 kg equations, respectively, 0.05 0.97), -0.37 0.27), 1.82 0.08), -1.50 0.06) depots, random components square error prediction 73 26% similarly 99, 85, 62, 61% Both predicted accurately within bounds experimental error. considered adequate initializing depot differential DGM other simulation models.