Relationship between follicle number and wool production

Abstract

The relationship between follicle number per unit area and wool production per unit area was examined in strong-wool (South Australian) and medium-wool (Peppin) Merino sheep. In four groups of strong-wool sheep (varying in number from 103 to 197 sheep) non-significant positive correlations were observed between follicle number per unit area and the amount of clean wool delineated by a 1 in. calliper. In two groups of strong-wool sheep (178 ewes and 169 rams) and one group of medium-wool sheep (184 ewes) the relationship between follicle number and unit area wool production was inferred from the association between number and fibre weight. There was a highly significant negative correlation (r = – 0.45 approx.) between number and fibre weight in each group. Further, a highly significant difference was observed between sire groups in mean fibre weight after adjustment for differences in follicle number. It was concluded that there was a small positive correlation between follicle number and wool production. This association was so small as to be of dubious biological significance. There were strong indications of a negative genetic correlation between follicle number and wool production, although this did not attain statistical significance.