Abstract
In order to clarify the growth pattern of body measurements of Japanese Black beef steers, the body measurements were collected from 801 steers of Japanese Black cattle on progeny testing at Miyazaki and Kagoshima Prefectural Livestock Experimental Stations from 1986 to 1993. Four non-linear models (Logistic, Gompertz, Von Bertalanffy and Brody) were used to fit growth patterns of the body weight (BW), withers height (WH), hip height (HH), body length (BL), chest girth (CG), chest depth (CD), chest width (CW), rump length (RL), hip width (HW), thurl width (TW) and pin bone width (PBW) . The coefficients of determination were more than 70.0% for all body measurements except TW and PBW fitted by four non-linear models. Logistic model was the best fitted of all non-linear models for every body measurement of Japanese Black steers. The mature estimate of body measurements of fattening steers were 913.5 kg, 167.1cm, 197.2cm and 273.9cm for BW, HH, BL and CG by use of Logistic model, respectively. Estimated BW was reached to 66.6% of predicted mature size at the end of fattening (about 20 months of age) and also reached to 77.4-81.5% for other body measurements.
