Genetic change in some South African Merino studs participating in the Merino plan

Data from the Merino Plan database were used to estimate genetic parameters for body weight (BW), clean fleece weight (CFW), fibre diameter (FD), staple length (SL) and total weight of lamb weaned. The number of records that could be used ranged from 26533 for TWW to 124252 for BW. Four-trait estimates of h were 0.35 for BW, 0.29 for CFW, 0.55 for FD, 0.26 for SL, and 0.05 for TWW (single-trait analysis). Genetic correlations among traits were mostly in accordance with published values. When expressed relative to the overall phenotypic means for the respective traits, geneti