Restricted maximum likelihood estimation of heritabilities for growth and feed utilization traits in Japanese Black using performance test records.

Records of 3,759 performance tested Japanese Black bulls, produced by mating of 382 sires and 3,031 dams, covering the period from 1974 to 1986 were analyzed. The data were obtained from 11 prefectural performance testing stations. All stations utilized standard testing procedures and regimen specified by the WAGYU Cattle Registry Association. Traits analyzed were final weight (FWT), average daily gain (ADG), concentrate intake (CON), roughage intake (ROU), ratio of roughage to total feed intake (RAT), feed conversion ratio of digestible crude protein (DCP), and feed conversion ratio of total digestible nutrients (TDN). The heritabilities were estimated by the Derivative-Free Restricted Maximum Likelihood and also by HENDERSON'S method III. The heritability estimates by the REML method were found to converge to one ultimate value regardless of whether or not values of initial heritability set in the program differ. Closeness of the initial value to the final estimate however seem to enhance the speed of convergence. The REML convergence estimates were also evidently influenced by the amounts of pedigree information used in the analysis. Generation 2 pedigree information seems to give the optimum heritability estimates. Estimates by REML method were higher than those by HENDERSON'S method III. The heritability estimates by REML were . 63 for FWT,. 28 for ADG,. 32 for CON,. 25 for ROU,. 18 for RAT,. 17 for DCP and. 18 for TDN. Anim. Sci. Technol. (Jpn.) 64 (7): 659-668, 1993