Heritabilities of nine production traits measured in 1 236 ram and 1 371 ewe progeny born from the same 73 sires in the Tygerhoek Merino Flock from 1971 to 1977, were estimated by halfsib analysis procedures. The heritability values obtained for seven body mass and wool production characters in ewes exceeded those of rams by 10,9 to 46,7 per cent. However, there was no sex difference in the heritability of crimp frequency while the heritability of fibre diameter was slightly higher in rams than in ewes. Scrutiny of the data showed that the sexual disparity in heritability values may be explained by a slightly greater genetic component for most characters in ewes compared to rams.
"Experientia docet" - Experience is the best teacher